2025-03-31-accounts

Birds Science People

2024/25

CONTENTS
Opening words	3
At a glance	4
Seeking solutions	6
Embracing everyone	8
Charting change	10
Delivering data	12
Sustaining supporters	14
Framing futures	16
Our volunteers	18
Our partnerships	20
Focus on England	22
Focus on Wales	24
Focus on Scotland	26
Focus on Northern Ireland	28
Being fit for the future	30
Thank you for your support	32
Our supporters	34
Our scientific output: 2024	36
Financial overview	38

YORKSHIRE CURLEW FIELDWORK, BY RICH BUNCE / WALKING PHOTOGRAPHER; SHORT-EARED OWL, BY DAVID TIPLING / BIRDPHOTO.CO.UK; SETTING NETS FOR RINGING, BY LEE BARBER / BTO

Birds Science People

FROM OUR CHAIR: PROFESSOR ZOE DAVIES

BTO continues to go from strength to strength, with staff, volunteers and members striving towards a better future for both birds and people, mediated through high-quality and impactful science. There have been many highlights during the year, as work to deliver our new strategy gained momentum.

BTO Youth collaborated with RSPB and WWF-UK to organise the second UK Youth in Nature Summit , which united almost 150 young people in their shared passion for protecting and enhancing biodiversity. This event is an important forum to inspire the next generation, given that young adults are increasingly less engaged with nature. Similarly, BTO joined forces with more than 400 organisations for the Restore Nature Now march in London, which called on politicians to step up and take meaningful action to recover biodiversity across the UK. Closer to home, on the doorstep of BTO HQ in Thetford, staff have been forging deeper connections with our local community and showcasing our work. This has included running a range of activities — such as outdoor fieldcraft sessions and arts projects — for groups of people that BTO has under-served in the past. All these activities underpin our desire to ensure that everyone feels a genuine sense of belonging. As such, BTO has a zero-tolerance approach to abuse of any kind, something that was underscored by the powerful A Girl & Birds blog, published during the year.

On a final, personal note, I would like to thank both Board and BTO staff for their kindness and support while I underwent breast cancer treatment throughout 2024. In particular, I am grateful to Iain Coucher for deputising as Chair.

FROM OUR CEO: PROFESSOR JULIET VICKERY

We celebrated 30 years of the BTO/JNCC/RSPB Breeding Bird Survey — a survey that has accumulated almost eight million records of nearly 300 species, from approximately 9,000 volunteers. It now underpins official government statistics, a range of approaches setting conservation priorities in the UK and Europe, and countless scientific publications to help better understand and conserve birds. It’s an extraordinary tribute to the power of the partnership BTO represents between scientists and volunteer observers. BTO Garden BirdWatch isn’t far behind in longevity and, like many of our schemes, is detecting threats to birds that were unknown or unforeseen at its inception. In this case, the vulnerability of Blackbirds to Usutu virus — a vector-borne disease more usually associated with the tropics. Garden BirdWatch’s surveillance network is helping to document the spread and impact of this disease on Blackbird numbers in and around Greater London and beyond.

While much of the value of these long-term schemes is their constancy between years, BTO science is always innovating. This year we deployed a flock of model birds to help improve the accuracy of seabird flight height estimates and hence better understand the risk of collision with offshore turbines. We launched a new raptor monitoring scheme in Wales with novel approaches to help engage diverse audiences in counting and conserving these charismatic species. And, thanks to a novel partnership and aviary and field techniques, 12 of our headstarted Curlews returned to East Anglia and attempted to breed. As is evident throughout this report, Birds Science People is a powerful combination — thank you for being part of it.

Trustees’ Annual Report & Financial Statements 2024/25 | 3

THE DIFFERENCE WE MAKE

Through our Bird Study journal, we brought together 22 important that scientific papers shed new light on the avian influenza outbreak and help direct our response to this devastating disease.

Our Together Through Nature (Thetford) project has given us the foundations needed for a successful community project, working with people who don’t usually have the opportunity to engage with nature and BTO.

funders and supporters, £7.3 million was spent during the yea carrying out, supporting and communicating our ornithological research and delivering engagem

During 2024/25, we received just under £800,000 through gifts in Wills, something for which we are phenomenally grateful.

4 | Trustees’ Annual Report & Financial Statements 2024/25

THE DIFFERENCE WE MAKE

----- Start of picture text -----
ar
ent.
----- End of picture text -----

Some 43,679 BTO volunteers have contributed to Garden BirdWatch, which has celebrated 30 years of recording this year, generating 10.6 million weekly observations.

“ BTO is working with Natural England to inform the adaptive response to climate change on SSSIs. ” Professor James Pearce-Higgins, Director of Science

Volunteers contributed 2,643,682 hours to BTO work during the year, mainly through our bird surveys and monitoring schemes. This incredible effort has an estimated financial value of more than £54 million.

Trustees’ Annual Report & Financial Statements 2024/25 |

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

SEEKING SOLUTIONS

How we manage our land and seas to meet our needs and those of the natural world is one of the most pressing conservation issues in the UK today, and BTO science is at the forefront of work to tackle this issue.

PROTECTED AREAS AND MIGRANT BIRDS

Under the 1979 Convention on Migratory Species, countries must protect migratory wildlife and the habitats upon which they rely. Well-managed protected areas are a vital conservation tool for this work, safeguarding species, supporting biodiversity, and reducing threats such habitat loss and hunting pressure. However, the role of protected areas in the conservation of migratory birds has proved difficult to establish, not least because of the dynamic nature of migratory populations.

By using data from across Europe, collated through the EuroBirdPortal, BTO’s Dr Jennifer Border and colleagues analysed the weekly distributions of 30 species, examining the degree of overlap with Europe’s protected areas and then comparing this to conservation policy targets. The study revealed that 13 of the species were inadequately covered by protected areas for some, or all, of the European part of their annual cycle under a target based on the 2020 Convention on Biodiversity framework, and none was adequately covered under a target based on the 2030 Convention on Biodiversity framework. Species associated with farmland had the lowest percentage of their weekly distribution protected.

The percentage of a species’ distribution within protected areas was positively correlated with its long-term population trend, even after accounting for confounding factors, suggesting a positive influence of protected areas on long-term trends. This work emphasises the positive contribution that an informed expansion of the European protected area system could play for the future conservation of migratory birds.

WHEATEAR, BY LIZ CUTTING / BTO

INFORMING BETTER PLANNING

Increasing demands on land for housing are contributing to biodiversity loss, both here in the UK and elsewhere in the world. There are, however, opportunities to use our knowledge of species and their habitat requirements to secure a more wildlife-friendly approach to urban planning, reducing its impacts on biodiversity.

Such an approach has the potential to deliver both conservation outcomes and the ecosystem services that benefit human wellbeing. To do this effectively, we need knowledge of the types of habitats and management practices that support the range of bird or other species of interest. This knowledge can be secured by analysing the data collected by BTO volunteers participating in our core schemes, but we then need to share this knowledge in ways that are relevant and accessible to those responsible for planning new housing developments.

In a 2024 study, BTO researchers used data from 160 urban sites in England, collected by volunteers taking part in the Wider Countryside Butterfly Survey, in which BTO is a partner (Cooper et al. 2024). Butterflies were chosen as the species group to investigate because they can be sensitive to small changes in habitat and are commonly seen in urban settings. These data were then used to quantify how individual butterfly species responded to 32 different measures of the urban environment.

Most of the species were found to respond more positively to urban greenspaces where management is less frequent, and higher butterfly counts were also found at urban sites with larger areas of semi-natural grassland, other managed greenspaces or adjacent arable land. Fewer butterflies were seen where the land was highly built up, and the greenspaces were more fragmented.

The results of this work can be used alongside related BTO research on birds in urban spaces, and there is the opportunity to develop a dedicated urban-environment biodiversity prediction tool. Practitioners could receive digestible species information, based upon the nature of their development site and the configuration of habitats within their plan.

When used over multiple plans, the developer should see which plan supports the most species or has the highest likelihood of encounters with particular species or species groups. This could help support developers in creating biodiverse spaces for people to live in, and reduce the reliance on off-site offsetting schemes, meeting the demand for new homes in a way that benefits both humans and the natural world alike. If anyone reading this is involved in landscape planning and would like to help us develop this tool, please get in touch.

6 | Trustees’ Annual Report & Financial Statements 2024/25

H

CASE STUDY: CLIMATE CHANGE

Marine renewables are an important part of our climate change response, but their construction and operation can impact birds and other marine life. BTO has continued its work in this area, improving the evidence base and working with partners across government, the NGO sector and industry to support both policy and practice.

SANDWICH TERN, BY DAVID TIPLING / BIRDPHOTO.CO.UK

TERNS IN A CHANGING WORLD?

Climate change is a key threat facing many of our seabirds, and offshore renewables are an important tool in mitigating its impacts. But these offshore developments can also pose a risk to seabirds, either through direct mortality or by reducing the accessibility of important foraging areas. Understanding these impacts is vital if we are to minimise these risks. A 2024 study of Sandwich Terns on the Norfolk coast used long-life GPS tags to follow movements over multiple years in an area with growing wind farm development. When the study began, there were five operational offshore wind farms within the distance that Sandwich Terns are known to commute on foraging trips. Two more offshore wind farms were under construction, and became operational during the course of the study.

The results revealed that Sandwich Terns entered offshore wind farms, but the extent to which they used these areas was found to vary over time and between sites. For the two wind farms that were completed during the study, there was a marked reduction in the amount of time birds spent at these sites. Although birds sometimes entered offshore wind farms while foraging, they appeared to avoid them when commuting between foraging areas and their colony. This created an apparent ‘funnelling’ effect between important feeding locations. The study informs future decisions about the placement of new wind farms and their potential impacts on seabirds (Thaxter et al. 2024).

ENHANCING THE EVIDENCE BASE

Back in 2012, BTO published an influential review using information from tracking studies and marine surveys to estimate how far seabirds travel from their colonies to feed during the breeding season. These estimates of seabird foraging ranges have been widely used to assess the potential for birds to interact with planned offshore wind farms, and to apportion any predicted impacts to individual breeding colonies. There has, however, been a rapid expansion in seabird GPS-tracking

studies since this review, which means that the evidence base for assessing the interactions between seabirds and wind farms is now much improved.

Working with colleagues from the RSPB Centre for Conservation Science and NIRAS Group (UK) Ltd, BTO researchers have updated the 2012 work to bring in the new information for 27 seabird species (Woodward et al. 2024). Among other findings, this BTOled study shows that, thanks to tracking data, the foraging ranges for eight species, including Kittiwake and Puffin, are more than 50% larger than those calculated previously.

This improved understanding of seabird foraging ranges ensures that decisions on the placement of wind farms are being made on the basis of the best available evidence. BTO’s ongoing work, tracking seabirds at different breeding colonies, will further refine our understanding and improve the evidence base that supports decision-making in the marine environment.

GUILLEMOT, BY SAM LANGLOIS / BTO

Trustees’ Annual Report & Financial Statements 2024/25 | 7

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

EMBRACING EVERYONE

One of our strengths is the breadth of opportunities for people to be part of our community through a shared love of birds. We are continuing our work to broaden our community, and co-creating opportunities with audiences that are new to us.

TOGETHER THROUGH NATURE

Over the past year, we’ve worked closely with partner organisations to support local communities — including many for whom access to nature is a new and transformative experience. By opening the door to birds and the natural world, we’ve not only introduced people to our work but also helped them build confidence and connection, additionally improving well-being in other aspects of their lives.

Our Together Through Nature pilot project took place in Thetford, Norfolk — the town where we have our headquarters, and where many of our staff live. Thetford has vibrant but often underserved communities, facing a range of economic, health and wellbeing challenges. We know that regular access to nature can play a powerful role in supporting mental and physical health, so this project set out to explore how we could make that access more inclusive and meaningful.

TOGETHER THROUGH NATURE EVENT / BTO

fostered a sense of ownership but also helped to embed our work in ways that were relevant and genuinely beneficial.

This pilot has laid strong foundations for future work. It has shown us how we can genuinely engage people who haven’t traditionally had access to nature, or to BTO. Looking ahead, we’re committed to offering more of these opportunities locally, and to exploring how this community-first approach can be expanded to new areas and partnerships across the UK.

BIRDS IN GREENSPACES

Urban areas are often overlooked in conservation, but they are where most people encounter nature in their daily lives. For many people, local parks and greenspaces offer the only connection to wildlife, playing a vital role in well-being, health, and community identity. We believe these spaces can — and should — be managed to better meet the needs of both people and wildlife. Over the past year, we’ve been laying the foundations for a new UK-wide initiative to do just that.

Through pilot work with communities and partners, we’ve been exploring how urban greenspaces can support thriving bird life while remaining welcoming and valuable to the people who use them. These spaces mean different things to different people — places to relax, to play, to connect, or to reflect — and their design and management must reflect that richness of purpose.

At the heart of our approach is community involvement. By working closely with local groups, including Fields in Trust in Scotland, we’ve been testing methods and gathering insights to ensure our survey is relevant, inclusive, and locally informed. This groundwork is preparing us for the full launch of Birds in Greenspaces in 2026. We are deeply grateful to the late Denis Summers-Smith, whose generous gift in Will has made this work possible. His legacy will help shape healthier, greener cities for generations to come.

Delivered in partnership with Civil Society Consulting, and with support from the John Swire 1989 Charitable Trust, we co-created this initiative with four grassroots community organisations. Using a bottom-up, collaborative approach, we listened to what communities were already doing, where the gaps were, and how we could add value — whether by integrating nature-based activities, creating welcoming spaces, or offering engaging introductions to BTO’s work.

Rather than reinventing the wheel, we built on existing community strengths — embedding nature and bird-focused engagement into ongoing programmes. This approach not only

TELLING BETTER STORIES

To better understand our impact, and deliver the right

opportunities, we need diverse evidence — including personal stories that show how our work empowers, engages, and enables people. These narratives are powerful: they amplify voices, reveal what matters to different communities, and help us understand how change happens from the perspective of those with whom we work. They are an important part of our work to become a more inclusive organisation. Over the past year, we’ve trained staff in storytelling techniques, helping them to better capture and integrate these insights into our work.

8 | Trustees’ Annual Report & Financial Statements 2024/25

EMBRACING EVERYONE

“ Our partnership with the experts at BTO will enable us to learn more about the value and benefits that our parks and greenspaces provide. By working together through our complementary projects, we will be able to learn more about how hard our parks are working for us by offsetting carbon emissions and providing valuable habitats for wildlife. ” Fields in Trust

Trustees’ Annual Report & Financial Statements 2024/25 | 9

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

CHARTING CHANGE

Over the year, we have continued to add to our high quality and long-term data about birds across countries and regions, thanks in large part to our amazing volunteer networks and a range of other partners.

GARDEN BIRDWATCH

Launched in January 1995, BTO’s weekly Garden BirdWatch survey celebrated three decades of monitoring the birds and other common wildlife found in the UK’s gardens. By the end of 1995, some 2,526 people had joined the project and were submitting data. Incredibly, three decades on from that first year of recording, 407 of those participants are still with us and entering their weekly counts. Over the intervening period we have received Garden BirdWatch data from 43,679 participants across 47,530 different gardens, from Land’s End to John O’Groats, and from the middle of London to the wilds of the Hebrides.

Garden BirdWatch continues to generate much-needed information on gardens, contributing data on seasonal and longer-term patterns of garden use, as well as contributing to our understanding of wildlife diseases — such as finch trichomonosis and Usutu virus — and the influence of gardening practices on our wildlife. The project is funded by its participants, to whom we are hugely grateful.

information on breeding pairs, locations, and productivity that is essential for informed conservation management. Although many individuals and groups collect these data, they are not currently collated or made easily accessible to support conservation efforts. Additionally, scarcer raptor species often receive more monitoring, leaving widespread species less well studied, and there is a shortage of new volunteers to continue or expand long-term monitoring efforts.

To address these challenges, we are delivering new projects that build on 20 years of experience with the Scottish Raptor Monitoring Scheme and other long-term monitoring work. The launch of Cudyll Cymru in Wales (see page 25) is one such example, but we are also exploring other opportunities. We want to streamline data collection, storage and reporting, making it more accessible and efficient for volunteers, and better at delivering the information needed by decision-makers and conservation practitioners.

Ultimately, improved monitoring of birds of prey will contribute to better-informed conservation policy and action, ensuring that these majestic birds grace our skies nationwide, now and into the future.

FILLING GAPS FOR RAPTORS

Despite the dedicated work of many volunteers and organisations, significant gaps remain in our knowledge of birds of prey and their populations. These species have faced long-term threats, including illegal persecution, habitat change and declines in prey populations, with new pressures — such as avian influenza — emerging in recent years. Without enhanced monitoring, declines in raptor populations may go unnoticed, and the success of conservation efforts could be overlooked.

To support effective conservation, more detailed data are needed, not just at the national level but also within specific countries and regions. While valuable BTO/JNCC/RSPB Breeding Bird Survey trends exist for some species, they do not offer the comprehensive

THE STATE OF NATURE

The monitoring schemes coordinated by BTO provide crucial information on the status of bird species at a range of spatial scales. The evidence that we generate is used for assessing conservation status and for identifying sites that are important for particular species. Many readers will be aware of how such data feed into high profile national reports, such as the State of Nature report published by a very broad suite of NGOs and other stakeholders.

However, the same data sources can also be used at smaller scales, and a report published in June 2024 provides a good example of this capability. The State of Yorkshire’s Nature , published by Yorkshire Wildlife Trust, is the first of its kind — a county-based multi-taxa assessment — and one that will help to evaluate and direct conservation and policy action. The BTO data that have gone into this report come from core surveys, including the BTO/JNCC/ RSPB Breeding Bird Survey, and collectively they underline the importance of Yorkshire for birds in a wider context. Of the 191 bird species that regularly breed or winter in Yorkshire, a quarter have major strongholds there.

The report provides a vital snapshot of how Yorkshire’s nature is faring, and it will help to direct conservation efforts over the coming years. For this reason, we are proud to have been part of this initiative and hope that it leads to similar approaches elsewhere within the UK.

KESTREL, BY PHILIP CROFT / BTO

10 | Trustees’ Annual Report & Financial Statements 2024/25

CHARTING CHANGE

CASE STUDY: SEABIRD MONITORING PROGRAMME

Our breeding seabird colonies are of international importance, and it is vital that we have up to date information on their status and health.

The Seabird Monitoring Programme monitors the population changes of our internationally important breeding seabird species, covering both coastal and inland colonies across the UK. The scheme was established by JNCC (then known as the Nature Conservancy Council) in 1986, working in partnership with a number of statutory government agencies and conservation organisations. BTO took on responsibility for running the scheme in July 2022, and has since been reviewing and developing the approaches used to support volunteers, manage and store data, and analyse and report on results.

Publication of the latest Seabird Monitoring Programme report, published in November 2024, documented changes in the abundance and productivity of breeding seabird species from 1986 to 2023, and included a detailed account of the 2021, 2022 and 2023 breeding seasons. The results from this report emphasised the impact of the recent outbreaks of high pathogenicity avian influenza, and are used more broadly to assess the health of the wider environment, to inform policy and for conservation action.

The Seabird Monitoring Programme is only possible thanks to the efforts of both professional fieldworkers and skilled nonprofessionals dedicated to the monitoring of the UK’s seabirds. We are very grateful to all participants who make it possible to report from across the Channel Islands, England, the Isle of Man, Northern Ireland, Scotland, the Republic of Ireland and Wales.

Trustees’ Annual Report & Financial Statements 2024/25 | 11

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

DELIVERING DATA

We have been working to increase the value and impact of the data collected by BTO volunteers and staff. Having greater access to the right kinds of data will help and support more people to take positive action for birds.

SHARING RECORDS MORE WIDELY

The BTO/JNCC/RSPB Breeding Bird Survey (BBS) plays a central role within the UK’s bird monitoring architecture. Each year, thanks to BBS volunteers, we are able to report on the population trends of close to 120 common terrestrial birds. The trends — which are official government statistics in their own right — are combined with those from the BBS’s predecessor, the Common Birds Census, taking our knowledge of changing populations back to the 1970s. They have highlighted the long-term declines of farmland and (more recently) woodland birds, and are used widely in research, including in recent BTO work on the value of protected areas.

Although these BBS data have formed the backbone of over 180 peer-reviewed papers, they have only been available on request. As part of our efforts to ensure our data and science are doing the most that they can for birds and people, we have now published the raw data — generated over the 30 years of BBS. Making the data available in this way means that there are in excess of seven million records of 26 million individual birds of 200 plus species that can be downloaded and used. We hope that this initiative will facilitate more research, both nationally and regionally, for the benefit of the UK’s birds.

THE M.C.H. BIRD ARCHIVE

At the beginning of October 2024, we welcomed the M.C.H. Bird Archive into the BTO Archives. This rich collection includes bird ledgers and natural history diaries kept over a period of five decades by the Reverend Maurice Bird (1857—1924). Bird was a wellrespected ornithologist, who was good friends with Emma Turner and other contemporaries. We are very grateful to his family for entrusting us with this unique material.

WEBSITE RELAUNCH

During the year we began work to redevelop the BTO website, improving its structure, navigation, and responsiveness, and reducing its carbon footprint. We wanted to make the site even more accessible, so that as many people as possible can access the wealth of information that it contains. The new site is based on the foundations of meeting the Web Content Accessibility Guidelines (WCAG) AA standard or better, with other guidance and best practice material — for example, dyslexia accessibility guidance — also shaping the end result.

Phase One of the work was completed just after year end, with the new website launched in early summer 2025. This phase dealt with structural elements, including delivering a site designed for mobile

devices, reflecting that two-thirds of our visitor traffic already uses the site on mobiles and we expect this proportion to increase in future. Phase Two of the work involves reviewing and reworking content, so that it is more informative and more accessible.

The website work also enabled us to relaunch our BirdFacts pages (www.bto.org/birdfacts), which bring together a wealth of information on the UK’s birds, much of which has been generated from BTO surveys and schemes, supported by our partners. These pages are particularly well used and we are looking at opportunities to bring more material into them, and into associated tools, such as the Trends Explorer — which allows anyone to access and interact with the latest information on our bird populations.

The work on our website is a core step in delivering our strategic objective to make it possible for anyone to access information about bird populations where they live throughout the UK. Associated with this is an expectation that will we see the use of BTO website-based data increase four-fold by 2030. We are particularly grateful to our members and supporters, whose financial support enabled us to direct core funds to this important piece of work.

CURLEW FIELDWORK, BY RICHARD BUNCE / WALKING PHOTOGRAPHER

BIRDS: BRILLIANT AND BIZARRE

BTO research, including that on bird ringing, disease surveillance and the tracking of migrant birds, featured in the Birds: Brilliant and Bizarre exhibition at the Natural History Museum in London. The exhibition showcased both the wonder of birds and the science that has delivered our understanding of their lives and the threats that they face. With just over 107,000 visitors, Birds: Brilliant and Bizarre was the most successful single group exhibition in the Museum’s history, and it was fantastic to have BTO science and data feature in such a high profile event.

12 | Trustees’ Annual Report & Financial Statements 2024/25

DELIVERING DATA

Trustees’ Annual Report & Financial Statements 2024/25 | 13

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

SUSTAINING SUPPORTERS

We want to ensure that everyone who works with us feels valued, and knows that they are playing an important role in tackling the biodiversity and climate crises. Over the past year we have continued to deliver projects that are helping us to do this.

LOOKING AFTER VOLUNTEER NETWORKS

Volunteers are the beating heart of our community, contributing an extraordinary 2.64 million hours to our work over the past year. Their dedication powers everything we do. This incredible effort is supported locally by the BTO Regional Network — itself made up of volunteers — who provide a local point of contact across 125 regions throughout England, Scotland, Wales, Northern Ireland, Isle of Man and the Channel Islands.

Recognising the pivotal role of volunteers in our mission, lifetime BTO member and Witherby Custodian Gillian Wills reached out to explore how she could help strengthen this vital network. Gillian visited us to discuss and refine a funding plan that met with our shared ambitions. Thanks to a multi-year commitment from Gillian, we have been able to employ Drew Lyness to improve support to the overall Regional Network, working closely with engagement staff in Scotland, Wales and Northern Ireland. In June 2024, Gillian visited BTO again, to meet Drew and other staff, and to see first-hand how this new role is already enhancing support for our dedicated volunteers across the UK.

We are deeply grateful to Gillian for her commitment and for making such a meaningful and lasting difference to the lives and work of our volunteer community.

GILLIAN WILLS AND DREW LYNESS, BY JON CARTER / BTO

A GIRL & BIRDS

We want everyone who works with us to feel valued, and know that they are playing an important role in tackling the biodiversity and climate crises. Our values, those that underpin how we work and how we behave when we interact with others, help us to deliver these aspirations, and they are shared with our staff, volunteers and supporters through our Code of Conduct. There are, however, occasions

when individuals fall short of expected standards of behaviour, and it is important that we are open about such failings, learn from them, and work to address them.

Early in 2024, we were invited by Alicia Hayden to support her in the publication of a blog relating her experiences as a young person in birding. The blog relates an incident of abuse that had, and continues to have, a devastating effect on her. Although Alicia’s story is difficult to read, it raises important issues that need to be heard. We chose to support her to share her experience because we believe it will help us do, and be, better in the future.

Alicia’s story was told through a blog on the BTO website, and through an art exhibition which was shown at our Thetford office before moving elsewhere. In addition to the support that we gave, we are very grateful to the support given to Alicia and her project by the Eric Hosking Trust. Sharing stories and experiences can help us, and others, to deliver positive change in our communities.

DEVELOPING SKILLS

Over the past year we have continued to deliver a variety of training opportunities, enabling participants to develop their birdwatching and surveying skills. These opportunities support individuals at different levels of knowledge, helping them to become better birdwatchers and to get more out of their hobby. This approach also benefits BTO and our work, increasing the pool of birdwatchers willing to participate in our surveys and longterm monitoring schemes. Both are equally important, and both contribute to our objective of enabling individuals to play a role in tackling the biodiversity and climate crises.

In addition to online and face-to-face training sessions, we have also been working to deliver other relevant resources and materials. Some of these have been aimed at specific audiences, such as those participating in particular projects. For BTO Garden BirdWatch, for example, we have produced targeted identification resources covering the other wildlife species monitored in this garden-based survey. These have been presented as an ongoing series in the quarterly magazine sent to paying participants.

Working with animator Will Rose — who delivered our strategy animation — we have used some of our training and identification expertise to support a series of You Tube videos that provide a very accessible way into bird identification. The series, written, animated and produced by Will and titled ‘What Bird is That?’, is rapidly becoming an engaging channel, which is helping people to recognise and enjoy the birds around them. The project is supported by Leica and fact-checked by BTO.

14 | Trustees’ Annual Report & Financial Statements 2024/25

ACTION AREAS — ACHIEVEMENTS AND PERFORMANCE

INFORMING POLICY DECISIONS FRAMING FUTURES

As recent work demonstrates, BTO expertise and extensive monitoring capabilities are helping us to understand the impacts of new and novel drivers of change in bird populations and their distribution.

RESPONDING TO AVIAN INFLUENZA

High pathogenicity avian influenza (HPAI) has emerged as a rapidly escalating threat to wild bird populations around the world. Within the UK, we have witnessed significant levels of mortality in our internationally important breeding seabirds and wintering waterfowl, as well as impacts on vulnerable bird of prey populations. The last three years have shown the power of surveyors and bird ringers, combined with BTO analysis, to track the spread of the disease and its impact on bird populations.

Being able to quickly bring together data and expertise from across BTO and its partner organisations has enabled us to respond to a rapidly evolving situation, and to then reflect on the lessons learned. During the year we published two special issues of our scientific journal Bird Study , bringing together 22 papers that shed new light on the scale of the outbreak and help to direct our response to this devastating disease. Our collective findings call for urgent investment in long-term monitoring, improved approaches to disease response, and greater integration of wildlife disease surveillance into public health and environmental policy. The papers have also been published as a ‘virtual collection’ online, where they will form a valuable resource for researchers and practitioners alike.

While we tend to think of HPAI as a disease of waterbirds and seabirds, three papers in the special issues highlight its impact on bird of prey populations. Because these birds tend to occur at low densities and live in remote areas they can be difficult to study. However, given their susceptibility to persecution, birds of prey are often covered by long-term monitoring programmes. The papers demonstrate the importance of long-term studies in helping to identify HPAI impacts in bird of prey populations and to then place these into context.

In Scotland, notable declines were found in the breeding productivity of several bird of prey species. The productivity of White-tailed Eagles and Golden Eagles was significantly reduced, significantly so in coastal areas where the likelihood of contact with infected prey or carrion was highest. Buzzards in the Easter Ross Peninsula, an otherwise stable population, experienced a sudden reduction in occupied territories and fledging success during 2022 and 2023, coinciding with confirmed HPAI cases in Pinkfooted Geese, and Peregrine Falcons in southern Scotland showed reduced productivity and increased breeding turnover postoutbreak. Without the efforts of the volunteers monitoring these populations we would have been unable to identify the impacts of the disease.

HUMAN CONFLICTS AND WILDLIFE

Human conflicts can have impacts on wildlife, as research published during the year and involving BTO staff reveals (Russell et al. 2024). When Russia invaded Ukraine on 24 February 2022, Greater Spotted Eagles from an important breeding population in southern Belarus were already on their spring migration, the first birds entering Ukraine over the following days. Some of these birds were carrying GPS tracking devices as part of a wider project studying the breeding behaviour and migration of this population.

The movements of 19 tagged birds were analysed alongside conflict data from the Armed Conflict Location and Event Data project. The analyses revealed that migrating eagles were exposed to conflict events along their migration through Ukraine and responded by exhibiting different migratory behaviour compared with previous years. They used fewer stopover sites within Ukraine and made large deviations from their usual routes, which ultimately delayed their arrival at the breeding grounds and likely carried an additional energetic cost. These birds fly at relatively low altitudes during this part of their migration, which would have brought them closer to the human conflict taking place. The study provides a rare glimpse into how human conflicts can impact other species in less obvious ways.

SUPPORTING DECLINING MIGRANTS

Our ongoing work, tracking the migrations of Cuckoos, has continued to deliver valuable new insights into the pressures that these birds face. One aspect of this work has involved collaboration with colleagues working on the species elsewhere within its European breeding range. The work set out to establish to what extent these birds use the same sites in different years.

Data from satellite-tracked adult male Cuckoos shows that, although all of the tracked birds returned to the same breeding grounds in consecutive years, they were much less faithful to sites used at other times of year. In only 18% of instances did the tagged individuals return to within 50 km of a previously visited nonbreeding site.

Like many other migratory birds, the Cuckoo is undergoing a substantial population decline in the UK and other parts of its breeding range. Understanding the drivers of site selection throughout their annual cycle is important, because such knowledge can be used to guide conservation efforts — such as the size and placement of protected areas along migration routes — to address such declines in this, and other, species.

16 | Trustees’ Annual Report & Financial Statements 2024/25

FRAMING FUTURES

----- Start of picture text -----
Trustees’ Annual Report & Financial Statements 2024/25 | 17
----- End of picture text -----

ACHIEVEMENTS AND PERFORMANCE

OUR VOLUNTEERS

BTO’s volunteers work in partnership with our scientists and survey organisers to deliver the evidence base that supports conservation action and decision-making processes, for the benefit of birds and people. Their knowledge, generosity and enthusiasm enable us to make a significant contribution to society.

REGIONAL ORGANISERS

Many of BTO’s core surveys are coordinated at the local level by Regional Organisers, volunteers who take on the responsibility for finding people to cover survey squares and submit returns. Being able to tap into their local knowledge and local connections makes a big difference to our ability to secure the levels of survey participation needed to deliver robust datasets.

A good example of the difference that our Regional Organisers are making is the level of coverage achieved for the 2023 UK Breeding Woodcock Survey, the peer-reviewed results from which were published in 2024. Over 1,000 volunteers took part in the survey, which made this the largest survey ever for this species in the UK. With its nocturnal habits and cryptic plumage, this is a challenging species to survey during the breeding season. The 1,192 survey squares covered by volunteers represents a 43% increase in coverage compared to the previous survey in 2013. For the first time, and thanks in particular to the coverage achieved in Northern Ireland, it has been possible to produce a Woodcock population estimate for the entire UK. A great deal of the thanks for this result is due to the volunteer Regional Organisers.

NESTING WOODCOCK, BY JOHN PROUDLOCK / BTO

YAP AND BTO YOUTH

BTO’s Youth Advisory Panel sits at the heart of the work that we are doing to inspire and support the next generation of birdwatchers and survey participants. Comprised of young volunteers, the Panel has played a key role in developing a comprehensive and inclusive

Youth Engagement Strategy, as well as taking on broader strategic responsibilities that inform the work that our charity does with young people.

Working alongside the Youth Advisory Panel are our Youth Representatives, who engage other young people with nature and science by organising events within their regions. They also work with their local communities and other stakeholders, and are part of the wider BTO Regional Network teams. Collectively, our young volunteers bring much-needed perspectives on birdwatching and volunteering to BTO, supporting and encouraging their peers to get involved in the opportunities that we are now able to offer. Importantly, they have identified and shaped ways for the organisation to deliver events and resources that meet the needs of younger people.

Another example of the incredible difference that our younger volunteers are making comes in the form of the Youth in Nature Summit. This two-day event, which seeks to inspire, empower and unite young people and leaders from across the environmental sector, takes significant planning and organisation. Members of our Youth Advisory Panel play a key role in the organising committee for the event, which has partnered BTO with RSPB and WWF-UK. The last event was held early in 2024, and the next is planned for 2026.

DELIVERING VALUE FOR NATURE

During 2024, volunteers contributed a staggering 2,758,402 hours to BTO work, mainly through our bird surveys and monitoring schemes. This represents an increase of 26% on the previous year and has an estimated monetary value of more than £54 million. The contribution of our volunteers to biodiversity monitoring is hugely important, especially when viewed against a backdrop of falling public spending on biodiversity, and the twin threats of climate change and biodiversity loss. Our data are needed now more than ever, and it is our amazing volunteers who enable us to collect our robust evidence and to leverage this for the public good.

We are working hard to provide more support to our volunteers and to offer increased opportunities for more people — from more backgrounds — to get involved in our work. By better understanding our volunteers and their reasons for supporting us, we hope to further develop the volunteering experience, so that individuals can clearly see the difference that they are making for birds, and for people.

18 | Trustees’ Annual Report & Financial Statements 2024/25

ACHIEVEMENTS AND PERFORMANCE

Trustees’ Annual Report & Financial Statements 2024/25 | 19

ACHIEVEMENTS AND PERFORMANCE

OUR PARTNERSHIPS

We are collaborative, working in partnerships with individuals and organisations to achieve our collective goals. During the year, these partnership have enabled us to reach and engage with new audiences.

RECOGNISING ACHIEVEMENT

Our ongoing partnership with the Marsh Charitable Trust has continued to celebrate contributions to different aspects of ornithological study, covering both the professional and voluntary sectors. This year, through these awards, we recognised the incredible work of Dirk Raes, the founder and driving force behind www.cr.birding.com. Through this website, Dirk facilitates nearly 7,000 colour-ringing projects across Europe entirely in his free time. We were also able to celebrate the work of Ken and Linda Smith, who lead the Woodpecker Network, working to understand and conserve the increasingly rare Lesser Spotted Woodpecker. Finally, we celebrated the efforts of BTO Youth Advisory Panel member Katie Monk and her engagement and fundraising work.

CELEBRATING A PIONEER

In October we partnered with Norfolk Wildlife Trust (NWT) to deliver Emma Turner at Hickling , celebrating this pioneering bird photographer and writer. A series of local events about her extraordinary life ended with the unveiling of an interpretation panel at NWT’s Hickling Broad reserve. We are fortunate to hold the Emma Turner Archive, including important photographic materials and notebooks. The project was recognised in The National Archives A Year in Archives review.

EMMA TURNER AT HICKLING, BY MIKE TOMS / BTO

VINE HOUSE FARM

It is estimated that more than half of all households in the UK engage in feeding birds in their gardens. BTO has long been at the forefront of monitoring and researching the effects of this form of food

provision on wild birds. This work has yielded fascinating insights into how the UK public’s bird feeding habits have impacted wild bird populations, and helped to produce best practice guidance for feeding birds safely. Our ongoing partnership with Vine House Farm provides an opportunity to engage with people feeding garden birds and to help them learn how to do this in the best ways for their birds. Vine House Farm is a conservation-award-winning farm, managed with wildlife in mind and environmental responsibility to the fore, and the partnership is based around a shared aim of making a positive impact for birds.

WORKING WITH OUR TRUSTEES

We remain deeply grateful to our Board of Trustees for their advice and expertise throughout the year. BTO benefits enormously from their commitment, support and challenge, and we deliver more and better as a result. For the first time in our organisational history the Trustees of BTO and RSPB met for an evening of discussion at the Cambridge Conservation Initiative offices in Cambridge. The meeting provided an opportunity for the two Boards to learn more about the work that is already being delivered in partnership by the two organisations, as well as paving the way for even closer working in the future.

RESTORING NATURE NOW

In June 2024, the Wildlife and Countryside Link convened the ‘Restore Nature Now’ march in London, and BTO staff, members and volunteers were among the more than 100,000 demonstrators who took part. This was the first time that the organisation had formally ‘signed up’ to a demonstration like this one, and it was an important step for us.

As an organisation we have a duty to generations of observers, who have contributed to our long-term monitoring schemes, to ensure that the evidence they have helped to collate is listened to and acted upon. BTO was at the march, in part, as an ‘advocate for evidence’. There is growing debate in academic circles about the role of scientists in the climate and biodiversity emergency, and an increasing sense that “scientists can and should advocate for one course of action over another if this is based upon their expert interpretation of the scientific evidence.” While we have traditionally laid out the facts and afforded decision makers complete freedom of choice, our role as honest advocates enables us to contribute to decision making in an evidence-led and well-informed way. If we are to deliver our strategic goal of using our science and our data to “secure the future for birds and nature” then this is a role we will increasingly need to play. Changing times and new challenges call for BTO to change too and to rise to those challenges. How we do this will be carefully considered in consultation with the BTO Board.

20 | Trustees’ Annual Report & Financial Statements 2024/25

----- Start of picture text -----
ACHIEVEMENTS AND PERFORMANCE
----- End of picture text -----

Trustees’ Annual Report & Financial Statements 2024/25 | 21

FOCUS ON ENGLAND

ENGLAND

BTO’s scientific work in England demonstrates the value of national long-term monitoring schemes in addressing local questions and, more broadly, highlights our role in bringing together stakeholders from different backgrounds to deliver for birds and people. You will find examples of engagement projects on pages 8 and 9.

22 | Trustees’ Annual Report & Financial Statements 2024/25

ACHIEVEMENTS AND PERFORMANCE

STOUR VALLEY TURTLE DOVES

Turtle Doves have suffered a c. 98% decline in their UK population since the 1960s, with just 3,600 breeding territories thought to remain. A temporary four-year moratorium on hunting in France, Spain and Portugal appears to have helped the species, but efforts to improve feeding opportunities during the breeding season are also needed.

With support from Defra, a project to create and maintain suitable Turtle Dove habitat is now running across a wide range of farms in the Stour Valley Farm Cluster farmer members’ area. BTO has been working with the Cluster to trial passive acoustic monitoring as a tool for assessing the status of Turtle Doves at these sites Because of the very low number of Turtle Doves remaining, it is not expected that Turtle Dove will be found at many of the sites, so these acoustic devices could provide a good means of assessing Turtle Dove presence, as they offer a better chance of detecting rare species than might be possible from short duration visits by human surveyors.

Turtle Dove was found at one site, Bombose Farm, holding territory for 21 days in 2024. Additionally, presence was confirmed for a further 73 bird species over the 10 sites. 191,213 ultrasonic recordings were also collected which, following analyses and validation, were found to include 46,386 detections of 10 bat species, and 295 detections of three small terrestrial mammal species. Four bush-cricket species and an audible moth species were also detected, underlining the value of this technology for the detection of these otherwise difficult to monitor species.

HEN HARRIERS IN ENGLAND

The Hen Harrier has been a species of significant conservation concern for several decades. Populations have been suppressed by illegal activities, including the killing of adult and immature birds and interference with nesting attempts. One consequence of this is that the English Hen Harrier population reached a historic low of just two breeding pairs in 2013, and the English population remains orders of magnitude lower than the estimated carrying capacity of 323—340 pairs. Attempts to reduce persecution of Hen Harriers in order to permit the recovery of the English population have been ongoing for many years but, until recently, have not resulted in any noteworthy population increase.

The population underwent a sudden and rapid increase from 2018, concurrent with a trial of a new management approach — termed ‘brood management’. The reasons for this increase were uncertain and the trial itself proved particularly controversial. Set against this background, BTO was commissioned by Natural England to carry out a population modelling study. This work modelled likely trends in the English Hen Harrier population under a range of scenarios, in order to evaluate the likelihood of each of these mechanisms having contributed to the observed increase in breeding attempts.

The results of the analysis suggest that improvements in one or both of survival and settlement rates were more likely reasons for the observed increase in the English Hen Harrier population,

rather than any uplift in productivity from the direct effects of brood management. The direct benefits of brood management and diversionary feeding to Hen Harrier productivity appear to have been minimal, a finding that provided valuable evidence to Natural England’s review of the trial.

YORKSHIRE DALES CURLEWS

Ongoing fieldwork in the Yorkshire Dales, carried in partnership with a broad range of other organisations, is continuing to explore the feasibility of potential Curlew-friendly Environmental Land Management Scheme (ELMS) options. The fieldwork has involved tracking GPS-tagged birds to explore their use of local habitats and to determine breeding success. The project is also trialling novel, farmer-led approaches to the monitoring of this species.

It is vital that wader-friendly farming is actively supported and incentivised, otherwise it is likely that increases in woodland planting and changes in the timing of grass cropping and livestock grazing would reduce the value of many Yorkshire Dales farms for Curlews and other breeding waders.

YORKSHIRE DALES CURLEW FIELDWORK, BY RICH BUNCE / WALKING PHOTOGRAPHER

OYSTERCATCHERS ON THE EXE

The Exe Estuary in Devon is a nationally important site for Oystercatchers wintering in the UK. However, the proportion of this species found in south-west England and wintering on the Exe declined from 60% in the late 1980s to 35% by the late 2010s. A study, published in 2024, used 45 years of data collected by volunteers taking part in the Wetland Bird Survey (WeBS) to investigate why.

The study found that kleptoparasitism by Carrion Crows and Herring Gulls could help to explain the trends observed on the Exe Estuary. Carrion Crows and Herring Gulls are known steal food from the Oystercatchers, and juvenile Oystercatchers suffer more than adults, resulting in them spending time on sites away from the Exe in order to meet their food requirements. This study demonstrates the value of long-term monitoring schemes in understanding species trends in specific areas. Comparisons of regional and national data allow for the formulation of targeted conservation measures to prevent future population declines.

Trustees’ Annual Report & Financial Statements 2024/25 | 23

TITLEFOCUS ON WALES

WALES

During the year, BTO Cymru staff launched a major new initiative, Cudyll Cymru, to better understand the changing fortunes of four widespread raptors and Raven. Staff also delivered policy-relevant science and engagement activities, the latter aimed at increasing the numbers and diversity of people involved in our work in Wales.

24 | Trustees’ Annual Report & Financial Statements 2024/25

ACHIEVEMENTS AND PERFORMANCE

MONITORING WELSH RAPTORS

Wales is home to 17 breeding raptor species which, given their position at the top of the food chain and public appeal, lend themselves to dedicated monitoring efforts. Additionally, some of these birds of prey are designated features of a number of protected areas in Wales, including Sites of Special Scientific Interest and Special Protection Areas.

Current bird monitoring approaches often struggle to provide information on raptors, which typically live at low population densities and which can be difficult to monitor through our core, multi-species schemes. Cudyll Cymru aims to address the gaps in the current data provision for some of these iconic birds in Wales. The project is using a patch-based monitoring approach for four widespread raptor species (Buzzard, Red Kite, Sparrowhawk and Kestrel) and Raven — which shares many ecological traits and is similarly under-monitored within Wales.

In order to deliver the level of geographical coverage required, the project is working to expand the available volunteer network. For this reason, there has been a strong focus this year on recruiting, training and upskilling potential volunteers, ahead of the first field season. The data collected through Cudyll Cymru will serve as a baseline for monitoring future population trends, and will also provide essential information to underpin effective conservation action. Through this project we are supporting the Welsh Government’s legal commitments to wildlife protection. The project is being funded by the Nature Networks Programme, delivered by the Heritage Fund on behalf of the Welsh Government.

TRACKING DISEASE IMPACTS

BTO Cymru staff have led on work to explore the extent to which the records of birdwatchers can be used to identify the impacts of avian influenza (Macgregor et al. 2024). Using observations of seabirds, recorded at locations around the North Sea during the autumn migration period, the BTO team tested for differences in migration counts before and after the onset of recent avian influenza outbreaks. The observations used came from semistructured sea-watching counts, submitted to Trektellen — an online database through which individuals store their migration counts in a standardised manner. Although a private initiative, Trektellen works in partnership with BTO and similar organisations in other countries.

The analysis revealed changes in the migration counts for four species that were known to have suffered from significant avian influenza mortality, together with declines in two additional species thought to have been unaffected by the disease. The work demonstrates that sea-watching observations can contribute to monitoring the ongoing impacts of avian influenza on seabird populations.

The results also highlight the value in using information from multiple sources, not least because our response to avian influenza has largely been informed by the evidence of mortalities at monitored seabird colonies. Using sea-watching records may pick up declines in colonies that are not monitored, perhaps

because they are located in other countries or in remote locations. In this respect, these data are complementary to the structured seabird monitoring taking place through initiatives such as the Seabird Monitoring Programme. The study also identified opportunities to further enhance the value of these data, by improving sea-watching coverage and increasing our understanding of seabird migration routes.

SHAG, BY DAVID TIPLING / BIRDPHOTO.CO.UK

THE STATE OF WELSH ENVIRONMENT

Over the last decade, BTO has been involved in a project assessing the state of the Welsh environment, bringing its expertise and evidence into the Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP). Funded by Welsh Government, ERAMMP provides a range of scientific evidence to support the development of relevant policies, as well as helping to evaluate the effectiveness of the resulting delivery mechanisms within the farming and land use sectors. BTO is one of 23 partner organisations involved in this project.

While the primary purpose of ERAMMP is to provide national trend information for a range of habitats and (largely) natural resources, it has also reported on the outcomes achieved by Glastir — a sustainable land management scheme. Reporting on policy outcomes was a requirement of the European Union funding which supported the Glastir scheme. Although Glastir has come to an end, the results are also being used to inform the development of a new scheme, being implemented in Wales as a consequence of our leaving the European Union.

The bird data used in this work come from just over 300 Welsh squares covered in the BTO/JNCC/RSPB Breeding Bird Survey. Longterm trends for 60 bird species have been produced and these have been used in a series of indicators for particular groups (e.g. birds of lowland farmland). This enables assessment of the policy delivery mechanisms at the heart of Glastir. Being able to make comparisons between survey squares where policy interventions have been used and those elsewhere, reveals whether or not the interventions are having their desired effect, an important consideration for policy development.

Trustees’ Annual Report & Financial Statements 2024/25 | 25

TITLE FOCUS ON SCOTLAND

SCOTLAND

Throughout the year, BTO Scotland staff and volunteers continued to deliver important research on some of the country’s most iconic species, and worked to upskill our existing volunteer base and attract new participants and supporters.

26 | Trustees’ Annual Report & Financial Statements 2024/25

ACHIEVEMENTS AND PERFORMANCE

ADDRESSING WADER DECLINES

Low rates of nest and chick survival have driven large declines in breeding wader populations across Scotland (and elsewhere). While habitat availability and quality have played an important role in wader population trends over the long term, the most common direct cause of wader nest and chick failure is predation. Remaining strongholds of wader breeding success are generally found in areas where the rates of nest and chick predation are relatively low, such as on islands, near intensively-managed grouse moors, and in nature reserves managed for breeding waders.

Landowners and managers can become frustrated when the conclusions reached by scientists and policy-makers run counter to their own understanding and experience, and this is particularly the case with contentious issues, such as the impacts of predators. Using cameras to monitor the outcome of wader nesting attempts can help to make the information gathered accessible to a wide range of stakeholders, additionally providing more definitive information on predator identities than data generated by most other kinds of monitoring.

During the year, BTO Scotland staff published a BTO Research Report on a pilot project trialling the use of trail cameras by land managers and other wader conservation stakeholders to monitor the outcome of wader nesting attempts. As well as collecting valuable information on the outcomes of 87 wader nesting attempts, made over two years, the project demonstrated that land managers are well placed to contribute wader nest camera records that can be usefully combined with those of individuals from environmental non-governmental organisations or academic backgrounds.

The approach outlined in the report can deliver cost-effective, inclusive monitoring and robust, co-produced datasets. It can also help to overcome some of the challenges that exist when working on these species within the political and social frameworks that currently dominate much of the debate around wader conservation.

UNDERSTANDING SHORT-EARED OWLS

Short-eared Owl populations are poorly understood, but their numbers are thought to have decreased in many parts of their range. Work by BTO Scotland staff on Short-eared Owls, published during the year through two peer-reviewed papers, adds further vital knowledge to our understanding of these birds and their requirements. Such knowledge can then be used to inform conservation action.

John Calladine, working with researchers from other European countries, used tracking technology to study Short-eared Owl movements. The results revealed the pronounced plasticity in the movement patterns of these birds, both individually and across wider populations. For example, distances between sequential breeding areas of individual owls were found to range from 41 to 4,216 km, and there was similarly low fidelity to areas used at other times of the year. Conservation planning and assessment for this species and its habitats must, therefore, acknowledge the uncertainties associated with such nomadic behaviour.

In a second paper, John Calladine and BTO colleagues were able to quantify Short-eared Owl use of moorland habitats in Britain, and to make comparisons between these sites and the more natural dwarf shrub habitats the birds also use in Norway. The results showed that a preference for the owls to hunt over grass-dominated areas within managed moorland here, contrasted with a tendency to hunt over dwarf shrubs in Norway. The observed differences likely reflect the availability of small mammal prey and how this varies between largely single-species stands of managed heather in Britain and the more diverse dwarf shrubland in Norway. The work indicates that how we manage habitats within our moorland landscapes has implications for Short-eared Owl conservation. This will be of particular importance should changes in land use and associated management approaches be introduced.

WORKING ACROSS BORDERS

The power of working collaboratively across countries, again to better understand the challenges facing our migrant birds, was also evident in other BTO Scotland work this year. The Arctic Skua, which has experienced substantial population declines across the European part of its range and which is now Red-listed as a Bird of Conservation Concern, has been a particular focus for our work in Scotland. It is thanks to a number of generous individuals that our work on this species has been possible.

One aim of this project has been to improve our understanding of Arctic Skua migratory routes and strategies, and the new work delivers this. Together with researchers from Norway, the Netherlands, Germany and the Faroe Islands, Nina O’Hanlon and her BTO colleagues were able to follow the movements of 131 Arctic Skuas from breeding colonies located in Scotland, the Faroe Islands, Norway and Svalbard. The study revealed that the birds from these colonies use several discrete staging areas during migration, with an area of high marine productivity in the mid North Atlantic being of particular importance. Identifying the non-breeding distribution, migratory strategies and degree of connectivity between Arctic Skua populations provides a vital step towards linking conditions during migration to population dynamics. From this, it is then possible to prioritise future research and conservation actions.

ARCTIC SKUA, BY SARAH HARRIS / BTO

Trustees’ Annual Report & Financial Statements 2024/25 | 27

FOCUS ON NORTHERN IRELAND

NORTHERN IRELAND

BTO Northern Ireland work has ranged from the monitoring of breeding seabirds to research into farmland birds and hosting public events — the latter open to everyone, to help increase engagement with our work across the country.

28 | Trustees’ Annual Report & Financial Statements 2024/25

ACHIEVEMENTS AND PERFORMANCE

BARRIERS TO BIOLOGICAL RECORDING

Northern Ireland has its own country-specific environmental policies and biodiversity strategy, which are implemented and monitored by the Department of Agriculture, Environment and Rural Affairs (DAERA). As elsewhere within the UK, biodiversity monitoring is mainly coordinated by environmental NGOs, such as BTO, with data collected by volunteers. However, when it comes to biodiversity data, Northern Ireland is considered to be relatively data-poor and BTO has led on a project to understand why this might be, and what to do about it.

BTO staff — working with colleagues from JNCC as part of the Terrestrial Surveillance Development and Analysis programme — assessed current barriers to participation in biological recording in Northern Ireland. The work involved an initial questionnaire to stakeholders, semi-structured interviews, collation of relevant information on biological recording in the country, and a workshop to discuss and verify the findings. Through this process it was possible to identify a number of initiatives and actions that would address the key barriers.

A lack of staff capacity across the environmental NGOs in Northern Ireland was one of the barriers identified, with knock-on effects on volunteer support, engagement and training. Another important barrier was social and cultural issues, which could be addressed by increasing awareness of the natural environment amongst the wider population of Northern Ireland’s 1.9 million residents. BTO’s Ripple Project is already demonstrating how such engagement can work in practice, working with individuals and communities in a supported bottom-up approach. A significant education and awareness programme, supported by training and backed by increased staff resource within the environmental NGOs, should help to grow capacity to collect the biodiversity monitoring data that is urgently needed.

INFORMING FARMING POLICIES

Fieldwork continued as part of a six-year project to explore the responses of birds to the agri-environment scheme approaches being used in Northern Ireland. Agri-environment schemes seek to support farmers to deliver management that boosts biodiversity on farmed land and delivers other environmental benefits. The project involves surveying 202 1-km survey squares, and focusing on plots managed to support breeding waders, seed-eating birds and upland species.

So far the work suggests that a number of bird species could be benefiting from scheme measures, but it will not be until the final formal analyses have been completed that firm conclusions can be drawn. Earlier work by BTO Northern Ireland staff showed that, despite previously being a highly important habitat for breeding Lapwing, Curlew, Redshank and Snipe, Northern Ireland’s lowland damp grasslands have undergone a drastic decline in their breeding wader numbers. Such evidence of decline underlines the urgency of finding the right policy solutions to support Northern Ireland’s bird communities. BTO’s continued work in this area, identifying declines and testing possible solutions, is now more important than ever.

A FIRST OFFICE IN NORTHERN IRELAND

In March we opened our first-ever office in Northern Ireland, reflecting our growing staff team — including our first intern — and the need for a permanent base for our community of members, volunteers and partners. The office, which is located in Lisburn, will enable us to better support the work we do within Northern Ireland, as well as those who work with us.

RIBBON CUT BY RICHARD GRAY, FROM NIEA — WHO FUNDED MUCH OF OUR SCIENCE AND ENGAGEMENT WORK IN NORTHERN IRELAND, BY SORREL LYALL / BTO

ENGAGING NEW PEOPLE WITH WILDLIFE

BTO’s Ripple Project seeks to engage new people with their local wildlife in Northern Ireland. This is a three-year pilot project, launched in 2022 and funded by the National Lottery Heritage Fund. A particular focus of the project over the past year has been to reach people who are under-represented in the conservation sector, providing them with opportunities to learn new skills and to secure the well-being and social benefits of experiencing nature with like-minded people.

Key to the success of this project has been our approach of partnering with community organisations, other nature organisations, and interested individuals to run introductorylevel nature events across Northern Ireland. An important aspect of this approach has been the successful recruitment of local volunteers, who facilitate monthly ‘Wildlife Wander’ events in different locations across Northern Ireland. These events involve relaxed walks in local greenspaces, where individuals can enjoy and learn about their local wildlife in a friendly group that welcomes both those new to nature and those looking to develop their wildlife skills. The volunteers are passionate about sharing nature experiences with others and helping more people to learn about local wildlife.

The Ripple Project has been recognised more broadly for how it is addressing the societal and cultural challenges of getting more people involved in biodiversity monitoring. With the support of our funders and partners we have been able to put in place the staff resources within Northern Ireland which then leverage additional support from volunteers, working together for the benefit of Northern Ireland’s birds and people.

Trustees’ Annual Report & Financial Statements 2024/25 | 29

PLANS FOR FUTURE PERIODS

BEING FIT FOR THE FUTURE

As our response to the threat of avian influenza proves, we are well-placed to detect, diagnose and even solve new and emerging problems. As work delivering our strategy continues to demonstrate, we are playing a stronger role, making our voice heard, and welcoming more people into our community.

ONGOING WORK AND FUTURE PROJECTS

Our overarching strategic objectives are to increase the impact of our work and grow the number and diversity of people working with us. Over the past year we have continued work on priority projects within our six Action Areas. These Action Areas, and the associated initiatives delivering the greatest returns for birds and people are:

Sustaining Supporters: We are ensuring that everyone who works with us feels valued, and knows they are playing an important role in tackling the biodiversity and climate crises. Over the past year we have continued our efforts to further improve the support that we give to our Regional Network, helping them to better serve our members and volunteers. This has included bringing our Garden BirdWatch Ambassadors and Youth Representatives more formally into the Network, which has increased the cohesion of our regional teams. We have also continued our programme of online and faceto-face training events, developing volunteers for the future. Work to tailor our communications to our supporters — recognising their individual contributions, needs and interests — is ongoing.

Charting Change: We are tracking changes in bird populations to understand their health, and that of the wider natural world. One important component of the work being delivered through this Action Area is a review of the monitoring needs for the UK’s birds. BTO staff have been developing a framework to ensure that we can provide the evidence needs for key species at both national and regional levels. Alongside this, there is an ongoing parallel review of BTO and partner monitoring scheme outputs, including analysis of gaps in species coverage at the country level. Our strategy has set targets for improving coverage to fill gaps and to move towards closer equity in coverage across the four countries of the UK. The gap analysis, due to be published in 2025, has highlighted key species groups on which to focus efforts in each country.

Framing Futures: We are using our science to track the impacts of, and inform responses to, future climate change and new environmental threats to birds. A strong focus over the past year has been on our response to the emergence of avian influenza and its impact. Alongside this, we have been exploring ways to better communicate the impacts that climate change is having on UK birds, using our long-term datasets to develop annual metrics that make these data easier to understand and interpret. We have also been working in partnership to explore the effectiveness of climate change mitigation and adaptation efforts, including in the field of restoration ecology.

Seeking Solutions: We are using our science to find ways to better manage land, coasts and seas, meeting the needs of both birds and people. We have continued to develop the evidence base needed to understand how land use and management affect our bird populations, testing policy approaches and highlighting potential solutions. Within the marine environment, we have identified opportunities to collect better data on seabird distributions, and evaluated approaches for using new information to make better predictions about the likely impact of proposed renewable developments on seabird populations.

Delivering Data: We are working with partners and communities to ensure our data and science are doing the most that they can for birds and people. The relaunch of our website, the bulk of the work for which took place over the year, is part of our efforts to make our work more accessible. Work to review our data provision began during the year, and the resulting report will help us to identify opportunities to make it easier for more people to access our data and information. We are also working to understand how best to use acoustic monitoring in our monitoring and research work.

Embracing Everyone: We are inspiring, engaging and empowering a greater diversity of people to discover and value nature. Work over the year to demonstrate our approach to inclusivity included the development of an accessible and engaging animation, which was then launched to our members and supporters in 2025. Our framework for becoming more inclusive provided the foundations for our new approach to project development — and we have used it in both the development of our Birds in Greenspaces survey and the community approach of Together Through Nature. An important thread within this Action Area is the ongoing work to develop our youth engagement programme, for which our aim is to secure sustainable funding to ensure that it continues to deliver for the next generation of birdwatchers and BTO volunteers.

STILL FROM BTO ANIMATION, BY VIOLA WANG

30 | Trustees’ Annual Report & Financial Statements 2024/25

PLANS FOR FUTURE PERIODS

Trustees’ Annual Report & Financial Statements 2024/25 | 31

SUPPORTING OUR WORK

THANK YOU FOR YOUR SUPPORT

Each year we need to raise millions of pounds to fund our work so that we can deliver the charitable outcomes for birds that are so important to our supporters. We are grateful for the wonderful financial support we receive from our members, donors, funders, partners, corporate members and customers.

LASTING LEGACIES

We remain deeply grateful for the unfailing generosity of our supporters. Once again, we received a remarkable level of support through gifts in Wills, this year totalling £798,827. Thanks to generous supporters remembering BTO in their Wills we have been incredibly fortunate to have received an average of £1 million annually over the last 10 years.

Income from gifts in Wills has an enormous impact on the work that we are able to do and ensures that our long-term surveys, such as the BTO/JNCC/RSPB Breeding Bird Survey, continue to thrive. We have made excellent progress towards the launch of our new Birds in Greenspaces survey which will start in spring 2026. This survey is only possible thanks to a generous gift from the estate of longterm BTO member, the late Denis Summers-Smith. Denis supported BTO generously in his life and we are so grateful to receive this gift, which is funding a community science project for all, one that we and his executor feel he would heartily approve of.

The Youth Engagement Team was awarded a 50% share of a gift in Will which they were able to use alongside other funding to support Bird Camps in England and Wales. Our Bird Camps have proved to be transformational for the young people who attend, providing a special opportunity for them to immerse themselves in nature, connect with like-minded peers, and develop their skills and passion for birdwatching and conservation.

Two gifts in Wills awareness events were held during the year, an online ‘Seabirds’ event, and an in-person event held at the Nunnery, on 75 years of monitoring wetland birds. Both events were well attended and we were even treated to a live ‘visit’ to a Scottish seabird colony with BTO ecologist, Sophie Bennet, who presented on camera, accompanied by an incredible soundtrack generated by the very vocal seabirds on the cliffs around her.

TRUSTS AND FOUNDATIONS

Making a positive difference in the local community around our Thetford headquarters has been a focus over the last two years, thanks to a generous grant from the John Swire 1989 Charitable Trust. Our Together Through Nature Thetford project has helped inspire hundreds more people about birds and nature, including many people who were new to BTO and even new to nature. In addition to providing an immediate benefit to participants, the project has allowed us to trial new ways of engaging different audiences and to bring the local Thetford community into our work place and onto our nature reserve.

A grant from the Esmée Fairbairn Foundation has also supported our efforts to make BTO accessible to more people. It has additionally allowed us to accelerate our efforts to reverse the fortunes of our breeding waders and to develop robust monitoring approaches for land that is being rewilded or managed for nature.

WITHERBY CUSTODIANS

The BTO Witherby Custodians are supporters who have matched Harry Forbes Witherby’s donation of £1,400 (from the sale of his collection of bird skins), which was used to fund the setup of BTO in 1933. In addition to helping to fund important pieces of BTO work, this group of committed supporters share their experiences and input to our plans in meetings with BTO staff.

In September the Witherby Custodians visited our Thetford headquarters, where they held a discussion with James PearceHiggins, our Director of Science, and Nick Moran, our Training Manager. This was followed by a visit to the nearby Lakenheath Nature Reserve, where two members of our inspirational Youth Advisory Panel — Alicia Hayden and Hadyn Fox — led the Custodians through some activities developed by the Youth Advisory Panel to inspire young people.

We are very grateful to our Witherby Custodians for their support and warmly welcome more Witherby Custodians. If you are interested in joining, please contact David Agombar by email at [e-mail].

CORPORATE MEMBERS

We are most grateful to the businesses who help us deliver our charitable objectives through their subscription to our Corporate Membership Scheme. We are also very appreciative of the support we receive from Boston Seeds, who regularly donate native wildflower seeds, packets of which are enclosed in our condolence cards. These cards are sent to the loved ones of supporters who have sadly passed away, to plant and encourage birds and wildlife, in their memory.

We are particularly grateful to our corporate sponsors Vine House Farm Ltd for their generous financial support. Vine House Farm sells a wide range of high quality bird feeders and bird food, much of which is produced on their own conservation-awardwinning farm. They are helping us by increasing awareness of our work amongst their customers, by supporting us financially and by hosting BTO events at their wonderful site near Spalding in

32 | Trustees’ Annual Report & Financial Statements 2024/25

SUPPORTING OUR WORK

Lincolnshire. We thank Lucy Taylor and Nicholas Watts, Charlotte Yeung and the rest of the staff and customers of Vine House Farm for supporting BTO.

RAISING FUNDS FOR RAPTORS

Our Winter Appeal in 2024 focused on the work we are doing with partners and volunteers to support the conservation of birds of prey in the UK. Despite our best efforts, significant gaps in our knowledge remain in relation to this iconic group of birds. Raptor monitoring is difficult, and birds of prey have large territories, can be very secretive, and often breed in remote and sometimes inaccessible locations.

We need to develop and support robust raptor monitoring across the whole of the UK, in the same way that we have successfully developed high-quality monitoring schemes like the Wetland Bird Survey and the Breeding Bird Survey. We promoted our appeal through mail, email, social media posts and Facebook adverts to reach a wider audience, gaining us many new supporters. It was one of our most successful appeals, raising over £100,000 — which will go a long way to supporting much needed raptor monitoring. We are grateful to everyone who kindly donated to help our raptors.

If you would like to know more about any of the projects or how you might support our work, please contact [e-mail]

----- Start of picture text -----
Trustees’ Annual Report & Financial Statements 2024/25 | 33
----- End of picture text -----

SUPPORTING OUR WORK

OUR SUPPORTERS

We are very grateful for the generous support that we have received, both in time and money, in the past year. In addition to members and other fieldworkers, there are many other individuals and companies who support BTO work with financial contributions. The Trust is particularly pleased to acknowledge the following corporate and other supporters.

CORPORATE SUPPORTERS 2024/25

BiOME Consulting Ltd, Boston Seeds, Brinvale Bird Foods, Eddowes Aviation Safety Limited, Garden Silhouettes Limited, Harvest Pet Products Ltd, Northumbrian Water, Nurture Landscapes Group, Opticron, Outdoor Alternative Ltd, P & R Seeds, Samuel McCausland Ltd t/a The Grass People, Severn Trent Water, Swallowtail Print, The Garden and Home Trading Company Limited, Vine House Farm.

CHARITABLE TRUSTS 2024/25

A G Leventis Foundation, Birdsong Walk, Painshill Park Trust Ltd, Cameron Bespolka Trust, Cecil Pilkington Charitable Trust, Downton Banister Trust, Esmée Fairbairn Foundation, Harris Charitable Trust, The John Swire 1989 Charitable Trust, Marsh Charitable Trust, Norfolk Wildlife Trust (Wymondham Branch), Primrose Hill Trust Fund, The British Birds Charitable Trust, The Dovehouse Trust, The Edinburgh Trust, The Emily Weircroft Charitable Trust, The Gilander Foundation, The Helen And Horace Gillman Trusts, The Lizandy Charitable Trust, The Mitchell Trust, The Penchant Foundation, The Saxham Trust, Woodpeckers Trust.

LEGACIES 2024/25

Avril R Allen, Dr A Robin Atherton, David A Bateman, Peter Beard, Joan W Blundell, Marian Braithwaite, Margaret A Bousfield, Frances C Cooke, Peter N Crawshaw, Brian Dougherty, Moira Duncan, Amelia M Durham, Peter H Dymott, Peter Firth, Robert W H Fletcher, Janet S A Griffiths, Margery Hannigan, Patricia E Harris, Sonia J Hearn, Stephen C Hibbard, Brian A Hinds, Nigel M Howland, Gordon M Ireson, Anthony Jevons, Mary Jobbins, Sheila M Kay, Brian Little, Rosemary Mason, Lesley Matthews, Enid Marion Mercer, Clive J Mills-Hicks, Christopher Murray, Ruth E Pryce, Kevin J Rees, Pamela Rhodes, Joyce Roberts, Thomas B Sedgwick, Mrs J Shears, Philip A L Souster, Robert J Stevens, Peggy Thorne, Richard M Tite, Christine M Purves, Douglas J Stevenson, Joyce A Tudor-Hughes, Kenneth E Russell, Anne H Walshaw.

IN MEMORIAM 2024/25

Stuart Matthew Barratt, Graham Ashley Birkin, Frank Brimblescombe, Jenny Brotherton, Brian Boyland, John & Anne Butterwick, Elizabeth (Liz) Clinton, Graham Cooper, David Cowan, Peter Leon Dykes, Anne Goodall, Frank Edwards, Jim Flegg, Margaret Galvin, Amanda Gibbs, Michael Goddard, Anne Goodall, Keith Wall Graham, Maximillian Slater Grant, Peter Heald, Colin & Jane Heape, Jean Hopwood, Joyce & Bob Howell, William (Bill) Hughes, Diana Jermyn, David Maxwell Jones, Richard Knightbridge, Tony Lewis, Brenda Palmer, Terry Paternoster, Elizabeth Prior, Jennifer Mary Rees, Stephen Roberts, Alma Russell, Tony Soper, Prudence Tapply, Barbara Thurgood, David Turner, Graham Vine, Doreen Waslin, Elizabeth ‘Pinkle’ Werner, Geraldine Wickson, Brian Wilson.

FUNDERS OF BTO WORK 2024/25

Aberdeen Offshore Wind Farm Limited, John Allen, Anguilla National Trust, Animal Plant Health Agency, Mike Archer, Bangor University, BBSRC, Bernwood Ecology, Jane Bradbury, Bureau Waardenburg bv, Butterfly Conservation, Cambridge Conservation Initiative, Carbon Trust, Catalan Ornithological Institute, Sir Charles Chadwyck-Healey, Richard Chadwick, Chilterns Conservation Board, Mike Clark, Nigel & Jacquie Clark, Derek Coleman, Simon Cooke, The Crown Estate, Mark Constantine, Curlew Recovery South Lakes, DAERA, Department of the Environment, Food and Rural Affairs, Department for Business Energy and Industrial Strategy, Department for Communities Northern Ireland, Devon Wildlife Trust, Duchy of Cornwall, Essex Birdwatching Society, EURING, European Commission, European Food Safety Authority, Marion Faulds, FERA, Forestry England, Forestry & Land Scotland, Frankfurt Zoological Society, Game & Wildlife Conservation Trust, Hartley Anderson Ltd., Heather Trust, Frank Hibbert, David Hodgson, Horizon Europe, ICF Consulting Services, Innovate UK, Institute of Avian Research, Helena Jefferson, Joint Nature Conservation Committee (on behalf of the statutory nature conservation agencies: Natural England, Natural Resources Wales, NatureScot and the Department of the Environment Northern Ireland), Devinder Kapur, Jenny Kingsland, Helen Lumley, MacArthur Green, Anne Masters, Muséum National d’Histoire Naturelle, National Trust, Natural England, Natural Resources Wales, Natural Environment Research Council, NatureScot, John Neighbour, North Wales Wildlife Trust, North York Moors National Park Authority, Northern Ireland Environment Agency, Ørsted, Jon Pavey, Pell Frishmann Consultants Ltd., Alex Rafinski, Rewilding Britain, Royal Society for the Protection of Birds, Sanger, Jane Schonveld, Scottish Government, Scottish Raptor Study Group, Scottish Ornithologists’ Club, Jeremy Shindler, Ken & Linda Smith, SOVON, Spoor, States of Guernsey, Suffolk Wildlife Trust, Swedish University of Agricultural Sciences, UK Centre for Ecology & Hydrology, UK Health Security Agency (UKHSA), University of Bristol, University of Cambridge, University of East Anglia, University of Edinburgh, University of Exeter, University of Stirling, University of Torino, Vattenfall, Nicholas Watts, Welsh Government, Wildfowl & Wetlands Trust, Gillian & Justin Wills, Working with Waders, WSP UK Ltd, Franziska Vogel, Diana Yardley, Yorkshire Dales National Park Authority, Zoological Society of London.

CLOCKWISE FROM TOP LEFT: MARSH AWARDS EVENING, BY ANTHONY SAJDLER; LUCY AND NICHOLAS WATTS, BY VINE HOUSE FARM, BTO REGIONAL NETWORK MEETINGS, BY DAWN BALMER / BTO

34 | Trustees’ Annual Report & Financial Statements 2024/25

SUPPORTING OUR WORK

OUR SCIENTIFIC OUTPUT: 2024

Peer-review is an important process, establishing the validity of research through review by other expert researchers in the field. It also provides valuable feedback, enabling researchers to improve their papers before publication. BTO reports annually across a number of indicators relating to its scientific work; three of these relate to scientific publications, reflecting the quality of the publications being produced, their impact, and the degree to which the work has been delivered through collaboration.

Our staff produced 52 papers (one a week!) that were first published in 2024, of which 46 were in ISI-listed journals and 17 were published in high impact publications (with an impact factor of 3.5 or greater). Twenty-seven of the publications were BTO-led, and 47 were in collaborative in nature, underlining the strong partnership approach to our work.

Abraham, A., Doughty, C., Plummer, K. & Duvall, E. 2024. Supplementary bird feeding as an overlooked contribution to local phosphorus cycles. Frontiers in Ecology and the Environment 22 : 2793. https://doi.org/10.1002/fee.2793

Border, J.A. , Boersch-Supan, P. , Pearce-Higgins, J.W. , Hewson, C. , Howard, C., Stephens, P.A., Willis, S.G., Houston, A., Gargallo, G. & Baillie, S.R. 2024. Spatial variation in spring arrival patterns of Afro-Palearctic bird migration across Europe. Global Ecology & Biogeograph y 33 : e13850. https://doi.org/10.1111/geb.13850

Allain, S.J.R., Leech, D.I., Hopkins, K., Seilern-Moy, K., Rodriguez-Ramos Fernandez, J., Griffiths, R.A. & Lawson, B. 2024. Characterisation, prevalence and severity of skin lesions caused by ophidiomycosis in a population of wild snakes. Scientific Reports 14 : 5162. https://doi.org/10.1038/s41598-024-55354-5

Bowler, D.E., Boyd, R.J., Callaghan, C.T., Robinson, R.A. , Isaac, N.J.B. & Pocock, M.J.O. 2024. Treating gaps and biases in biodiversity data as a missing data problem. Biological Reviews 100 : 50—67. https://doi.org/10.1111/brv.13127

Bateman, I.J., Binner, A. Addicott, E.T., Balmford, B., Cho F.H.T., Daily, G.C., De-Gol, A., Eisenbarth, S., Faccioli, M., Ferguson-Gow, H., Ferrini, S., Fezzi, C., Gannon, K., Groom, B., Harper, A.B., Harwood, A., Hillier, J., Hulme, M.F., Lee, C.F., Liuzzo, L., Lovett, A., Mancini, M.C., Matthews, R., Morison, J.I.L., Owen, N., Pearson, R.G., Polasky, S., Siriwardena, G. , Smith, P., Snowdon, P.P., Tippett, P., Vetter, S.H., Vinjili, S., Vossler, C.A., Watson, R.T., Williamson, D. & Day, B.H. 2024. How to make land use policy decisions: integrating science and economics to deliver connected climate, biodiversity, and food objectives. Proceedings of the National Academy of Sciences 121 : e2407961121. https://doi.org/10.1073/pnas.2407961121

Brides, K., Wood, K.A., Leighton, K. , Barbour, J., Petrek, S.W., Cooper, J., Vickers, S.H., Christmas, S.E., Middleton, J. & Grogan, A. 2023. Moult migration, site fidelity and survival of Canada Geese Branta canadensis caught at Lake Windermere, Cumbria. Wildfowl 73 : 43—63.

Brighton, C.H. , Massimino, D. , Boersch-Supan, P. , Barnes, A.E. , Martay, B. , Bowler, D.E., Hoskins, H.M.J. & Pearce-Higgins, J.W. 2024. The benefits of protected areas for bird population trends may depend on their condition. Biological Conservation 292 : 110553. https://doi.org/10.1016/j.biocon.2024.110553

Calladine, J. , Hallgrimsson, G.T., Morrison, N., Southall, C., Gunnarsson, H., Jubete, F., Sergio, F. & Mougeot, F. 2024. Remote tracking unveils intercontinental movements of nomadic Short-eared Owls Asio flammeus with implications for resource tracking by irruptive specialist predators. Ibis 166 : 896—908. https://doi.org/10.1111/ibi.13304

Boersch-Supan P.H. , Hanmer H.J. & Robinson R.A. 2024. Extended molt phenology models improve inferences about molt duration and timing. Ornithology 141 : ukae003. https://doi.org/10.1093/ornithology/ukae003

Calladine, J. , Southall, C., Wetherhill, A. & Morrison, A. 2024. Use of dwarf shrubland – grassland mosaics by a nomadic predatory bird, the Short-eared Owl Asio flammeus. Journal of Ornithology 165 : 1039—1049. https:// doi.org/10.1007/s10336-024-02174

Boersch-Supan, P.H. , Brighton, C.H. , Thaxter, C.B. , Cook, A.S.C.P. 2024. Natural body size variation in seabirds provides a fundamental challenge for flight height determination by single-camera photogrammetry. A comment on Humphries et al. 2023. Marine Biology 171 : 122. https://doi.org/10.1007/s00227-024-04396-4

Clark, B.L., Vigfúsdóttir, F., Wanless, S., Hamer, K.C., Bodey, T.W., Bearhop, S., Bennison, A., Blackburn, J. , Cox, S.L., d’Entremont, K.J. & Garthe, S. 2024. Northern Gannet foraging trip length increases with colony size and decreases with latitude. Royal Society Open Science 11 : 240708. https://doi.org/10.1098/rsos.240708

Boetzl, F.A., Sponsler, D., Albrecht, M., Batáry, P., Birkhofer, K., Knapp, M., Krauss, J., Maas, B., Martin, E.A., Sirami, C., Sutter, L., Bertrand, C., Bosem Baillod, A., Bota, G., Bretagnolle, V., Brotons, L., Frank, T., Fusser, M., Giralt, D., González, E., Hof, A.R., Luka, H., Marrec, R., Nash, M.A., Ng, K., Plantegenest, M., Poulin, B., Siriwardena, G.M. ,Tscharntke, T., Tschumi, M., Vialatte, A., Van Vooren, L., Zubair-Anjum, M., Entling, M.H., Steffan-Dewenter, I. & Schirmel, J. 2024. Distance functions of carabids in cropfields depend on functional traits, croptype and adjacent habitat: a synthesis. Proceedings of the Royal Society B . 291 : 20232383. https://doi.org/10.1098/rspb.2023.2383

Cooper, J.E.J. , Plummer, K.E. , Middlebrook, I. & Siriwardena, G.M. 2024. Using butterfly survey data to model habitat associations in urban developments. Journal of Applied Ecology 61 : 773—783. https://doi.org/10.1111/1365-2664.14583

Davies, J.G. , Boersch-Supan, P.H. , Clewley, G.D. , Humphreys, E.M. , O’Hanlon, N.J. , Shamoun-Baranes, J., Thaxter, C.B. , Weston, E. & Cook, A.S.C.P. 2024. Influence of wind on Kittiwake Rissa tridactyla flight and offshore wind turbine collision risk. Marine Biology 171 : e191. https://doi.org/10.1007/s00227-024-04508-0

Bonaldi, C., Vardanis, Y., Willemoes, M., Hewson, C.M. , Atkinson, P.W. , Nilsson, J-Å., Klaassen, R.H.G., Strandberg, R., Tøttrup, A.P., Howey, P.W., Alerstam, T. & Thorup, K. 2024. Recurrence, fidelity and proximity to previously visited sites throughout the annual cycle in a transSaharan migrant, the Common Cuckoo. Journal of Avian Biology 2024 : e03183. https://doi.org/10.1111/jav.03183

Davies, J.G. , Dytham, C., Robinson, R.A. & Beale, C.M. 2024. Estimating the distribution of reed Phragmites australis in Britain demonstrates challenges of remotely sensing rare habitat types at large spatial scales Scientific Reports 14 : 22271. https://doi.org/10.1038/s41598-024-73030-6

Duffield, S.J., Morecroft, M.D., Pearce-Higgins, J.W. & Taylor, S.D. 2024. Species- or habitat- based assessments of vulnerability to climate change? Informing climate change adaptation in special protection areas for birds in England. Biological Conservation 291 : 110460. https://doi.org/10.1016/j.biocon.2024.110460

Gardner, E., Robinson, R.A., Julian, A., Boughey, K., Langham, S., Tse-Leon, J., Petrovskii, S., Baker, D.J., Bellamy, C., Buxton, A., Franks, S. , Monk, C., Morris, N., Park, K.J., Petrovan, S., Pitt, K., Taylor, R., Turner, R.K., Allain, S.J.R., Bradley, V., Broughton, R.K., Cartwright, M., Clarke, K., Cranfield, J., Fuentes-Montemayor, E., Gandola, R., Gent, T., Hinsley, S.A., Madsen, T., Reading, C., Redhead, J.W., Reveley, S., Wilkinson, J., Williams, C., Woodward, I. , Baker, J., Briggs, P., Dyason, S., Langton, S., Mawby, A., Pywell, R.F. & Bullock, J.M. 2024. A family of process-based models to simulate landscape use by multiple taxa. Landscape Ecology 39 : e102. https://doi.org/10.1007/s10980-024-01866-4

Gordon, I.J., Sollmann, R., Rantanen, E.M., Johnson, J.A., Evans, K.L., Penteriani, V. & Boersch-Supan, P. 2024. Ten years on for the Letter from the Conservation Front Line. Animal Conservation 27 : 139—140.

Goss-Custard, J.D., Austin, G.E. , Frost, T.M. , Sitters, H.P. & Stillman, R.A. 2024. Decline in the numbers of Eurasian Oystercatchers Haematopus ostralegus on the Exe estuary Special Protection Area. Ardea 112 : 267—283. https://doi.org/10.5253/arde.2023.a23

Groh, C., Siriwardena, G.M. & McMahon, B.J. 2024. Diversity in Irish and British avifauna assemblages: what can variation in diversity profiles reveal about the forces that drive assemblage composition and structure? Ecology and Evolution 14 : e70143. https://doi.org/10.1002/ece3.70143

Hereward, H.F.R. , Brenchley, A., Facey, R.J., Hughes, J., Lindley, P.J., Taylor, R.C. , Wilson, M.W. & Macgregor, C.J. 2024. Status and distribution of Rook Corvus frugilegus in Wales in 2022/23. Milvus 3: 32—50.

Hereward, H.F.R. , Macgregor, C.J. , Gabb, O., Connell, A., Thomas, R.J., Cross A.V. & Taylor, R.C. 2024. Modelling population-level impacts of wind farm collision risk on Welsh Red Kites. Milvus 3 : 75—99.

Heward, C.J., Conway, G.J ., Hoodless, A.N., Norfolk, D. & Aebischer, N.J. 2024. Population and distribution change of Eurasian Woodcocks Scolopax rusticola breeding in the UK: results from the 2023 Breeding Woodcock Survey. Bird Study 79 : 109—123. https://doi.org/10.1080/00063657.2024.2345272

Hua, F., Wang, W., Nakagawa, S., Liu, S., Miao, X., Yu, L., Du, Z., Abrahamczyk, S., Arias-Sosa, L.A., Buda, K. & Budka, M., Carrière, S.M., Chandler, R.B., Chiatante, G., Chiawo, D.O., Cresswell, W., Echeverri, A., Goodale, E., Huang, G., Hulme, M.F. , Hutto, R.L., Imboma, T.S., Jarrett, C., Jiang, Z., Kati, V.I., King, D.I., Kmecl, P., Li, N., Lövei, G.L., Macchi, L., MacGregor-Fors, I., Martin, E.A., Mira, A., Morelli, F., Ortega-Álvarez, R., Quan, R.-C., Salgueiro, P.A., Santos, S.M., Shahabuddin, G., Socolar, J.B., Soh, M.C.K., Sreekar, R., Srinivasan, U., Wilcove, D.S., Yamaura, Y., Zhou, L. & Elsen, P.R. 2024. Ecological filtering shapes the impacts of agricultural deforestation on biodiversity. Nature Ecology and Evolution 8 : 251—266.

36 | Trustees’ Annual Report & Financial Statements 2024/25

OUR SCIENTIFIC OUTPUT: 2024

Kirkland, M. , Atkinson, P.W. , Aliácar, S., Saavedra, D., De Jong, M.C., Dowling, T.P.F. & Ashton-Butt, A. 2024. Protected areas, drought, and grazing regimes influence fire cccurrence in a fire-prone Mediterranean region. Fire Ecology 20 : 88. https://doi.org/10.1186/s42408-024-00320-9

Lonero, I., Eddowes, M.J., Burgess, M.D., Pearce-Higgins, J.W . & Phillimore, A.B. 2024. Temperature sensitivity of breeding phenology and reproductive output of the Common Redstart ( Phoenicurus phoenicurus ). Ibis 167 : 418—436. https://doi.org/10.1111/ibi.13376

Macgregor, C.J. , Gillings, S. , Balmer, D.E. , BoerschSupan, P.H. , Harris, S.J. , Hereward, H.F.R. , Humphreys, E.M. , Pearce-Higgins, J.W. , Taylor, R.C. , Troost, G. & Atkinson, P.W. 2024. Impacts of highly-pathogenic avian influenza on seabird populations in the North Sea are detectable in seawatchers’ migration counts. Bird Study 71 : 311—325. https://doi.org/10.1080/00063657.2024.2440826

MacIsaac, J., Newson, S. , Ashton-Butt, A. , Pearce, H. & Milner, B. 2024. Improving acoustic species identification using data augmentation within a deep learning framework. Ecological Informatics 83 : 102851. https://doi.org/10.1016/j.ecoinf.2024.102851

Macphie, K.H., Samplonius, J.M., Hadfield, J.D., PearceHiggins, J.W. & Phillimore, A.B. 2024. Tree taxon effects on the phenology of caterpillar abundance and biomass. Oikos 2025 : e10972. https://doi.org/10.1111/oik.10972

Martín Vélez, V., Cano-Povedano, J., Cañuelo-Jurado, B., López-Calderón, C., Céspedes, V., Ros, M., Sánchez, M.I., Shamoun-Baranes, J., Müller, W., Thaxter, C.B. , Camphuysen, C.J., Cózar & Green, A.J. 2024. Leakage of plastics and other debris from landfills to a highly protected lake by wintering gulls. Waste Management 177 : 13—23. https://doi.org/10.1016/j.wasman.2024.01.034

Massimino, D. , Baillie, S.R. , Balmer, D.E. , Bashford, R.I., Gregory, R.D., Harris, S.J. , Heywood, J.J.N. , Kelly, L.A., Noble, D.G. , Pearce-Higgins , J.W. , Raven, M.J., Risely, K., Woodcock, P., Wotton, S.R. & Gillings, S. 2024. The Breeding Bird Survey of the United Kingdom. Global Ecology and Biogeography 34 : e13943. https://doi. org/10.1111/geb.13943

Merondun, J., Marques, C.I., Andrade, P., Meshcheryagina, S., Galván, I., Afonso, S., Alves, J.M., Araújo, P.M., Bachurin, G., Balacco, J., Bán, M., Fedrigo, O., Formenti, G., Fossøy, F., Fülöp, A., Golovatin, M., Granja, S., Hewson, C. , Honza, M., Howe, K., Larson, G., Marton, A., Moskát, C., Mountcastle, J., Procházka, P., Red’kin, Y., Sims, Y., Šulc, M., Tracey, A., Wood, J.M.D., Jarvis, E.D., Hauber, M.E., Carneiro, M. & Wolf, J.B.W. 2024. Evolution and genetic architecture of sexlimited polymorphism in cuckoos. Scientific Advances 10 : eadl5255. https://doi.org/10.1126/sciadv.adl5255

Montràs-Janer, T., Suggitt, A.J., Fox, R., Jönsson, M., Martay, B. , Roy, D.B., Walker, K.J. & Auffret, A.G. 2024. Anthropogenic climate and land-use change drive shortand long-term biodiversity shifts across taxa. Nature Ecology and Evolution 8 : 739—751. https://doi.org/10.1038/s41559-024-02326-7

O’Hanlon, N.J. , van Bemmelen, R.S.A., Snell, K.R.S., Conway, G.J. , Thaxter, C.B. , Aiton, H., Aiton, D., Balmer, D.E. , Are Hanssen, S., Calladine, J.R. , Hammer, S., Harris, S.J. , Moe, B., Schekkerman, H., Tulp, I. & Humphreys, E.M. 2024. Atlantic populations of a declining oceanic seabird have complex migrations and weak migratory connectivity to staging areas. Marine Ecology Progress Series 730 : 113—129. https://doi.org/10.3354/meps14533

O’Hanlon, N.J. , Thaxter, C.B. , Clewley, G.D. , Davies, J.G. , Humphreys, E.M. , Miller, P.I. Pollock, C.J., ShamounBaranes, J., Weston, E. & Cook, A.S.C.P. 2024. Challenges in quantifying the responses of Black-legged Kittiwake to habitat variables and local stressors due to individual variation. Bird Study 71 : 48—64. https://doi.org/10.1080/00063657.2024.2305169

O’Hanlon, N.J. , van Bemmelen, R.S.A., Conway, G.J. , Thaxter, C.B. , Aiton, H., Aiton, D., Balmer, D.E. , Calladine, J.R. , Harris, S.J. & Humphreys, E.M. 2024. New insights into the migration and wintering areas of Scottish-breeding Arctic Skuas. British Birds 117 : 488—497.

Pickett, H.R.W., Robinson, R.A. & Nudds, R.L. 2024. Differential changes in the morphology and fuel loads of obligatory and partial migrant passerines over half a century in Britain. Movement Ecology 12 : 60. https://doi.org/10.1186/s40462-024-00497-3

Pirzio-Biroli, A., Crowley, S.L., Siriwardena, G.M. , Plummer, K.E. , Schroeder, J. & White, R.L. 2024. Not in the countryside please! Investigating UK residents’ perceptions of an introduced species, the ring-necked parakeet ( Psittacula krameri ). NeoBiota 93 : 1—24. https://doi.org/10.3897/neobiota.93.110122

Pollock, C.J., Johnston, D.T. , Boersch-Supan, P.H. , Thaxter, C.B ., Humphreys, E.M. , O’Hanlon, N.J. , Clewley, G.D. , Weston, E.D., Shamoun-Baranes, J.Z. & Cook, A.S.C.P. 2024. Avoidance and attraction responses of Kittiwakes to three offshore wind farms in the North Sea. Marine Biology 171 : e217. https://doi.org/10.1007/s00227-024-04542-y

Rivers, E.M., Short, M.J., Page, A., Potts, P.M., Hodder, K., Hoodless, A., Robinson, R. & Stillman, R. 2024. Factors influencing nest site selection in a rapidly declining shorebird, the Eurasian Curlew. Journal of Avian Biology e03286. https://doi.org/10.1111/jav.03286

Robinson, R.A. 2024. Understanding population change: the value of the EuroCES constant-effort ringing programme. Ringing & Migration 38 : 29—37. https://doi.org/10.1080/03078698.2024.2311771

Russell, C., Franco, A., Atkinson, P. , Väli, Ü. & AshtonButt, A. 2024. Active European warzone impacts raptor migration. Current Biology 34 : 2,272—2,277. https://doi.org/10.1016/j.cub.2024.04.047

Sandal, L., Sæther, B.E., Freckleton, R.P., Noble, D.G. , Schwarz, J., Leivits, A. & Grøtan, V. 2024. Species richness and evenness of European bird communities show differentiated responses to measures of productivity. Journal of Animal Ecology 93 : 1,212—1,224. https://doi.org/10.1111/1365-2656.14136

Stanbury, A.J., Burns, F., Aebischer, N.J., Baker, H., Balmer, D. , Brown, A.F., Dunn, T., Lindley, P., Murphy, M., Noble, D.G. , Owens, R. & Quinn, L. 2024. The status of the UK’s breeding seabirds: an addendum to the fifth Birds of Conservation Concern in the United Kingdom, Channel Islands and Isle of Man and second IUCN Red List assessment of extinction risk for Great Britain. British Birds 117 : 471—487.

Sutherland, W.J. Bennett, C., Brotherton, P.N.M., Butchart, S.H.M., Butterworth, H.M., Clarke, S.J., Esmail, N., Fleischman, E., Gaston, K.J., Herbert-Read, J.E., Hughes, A., Kaartokallio, H., Le Roux, X., Lickorish, F.A., Newport, S., Palardy, J.E., Pearce-Higgins, J.W. , Peck, L.S., Pettorelli, N., Primack, R.B., Primack. W.E., Schloss, I.R., Spalding, M.D., ten Brink, D., Tew, E., Timoshyna, A., Tubbs, N., Watson, J.E.M., Wentworth, J.E., Wilson, J.D. & Thornton, A. 2024. A horizon scan of global biological conservation issues for 2024. Trends in Ecology & Evolution 39 : 89—100. https://doi.org/10.1016/j.tree.2023.11.001

Thaxter, C.B. , Green, R.M.W., Collier, M.P., Taylor, R.C. , Middelveld, R.P., Scragg, E.S., Wright, L.J., Cook, A.S.C.P. & Fijn, R.C. 2024. Behavioural responses of Sandwich Terns following the construction of offshore wind farms. Marine Biology 171 : 58. https://doi.org/10.1007/s00227-023-04353-7

Tirozzi, P., Massimino, D. & Bani, L. 2024. Avian responses to climate extremes: insights into abundance curves and species sensitivity using the UK Breeding Bird Survey. Oecologia 204 : 241—255. https://doi.org/10.1007/s00442-023-05504-9

van Bemmelen, R., Moe, B., Schekkerman, H., Hanssen, S.A., Snell, K., Humphreys, L. , Mäntylä, E., Hallgrimsson, G.T., Gilg, O., Ehrich, D., Calladine, J. , Hammer, S., Harris, S. , Lang, J., Vignisson, S., Kolbeinsson, Y., Kimmo, N., Sillanpää, M., Sittler, B., Sokolov, A., Klaassen, R., Phillips, R. & Tulp, I. 2024. Synchronous timing of return to breeding sites in a long-distance migratory seabird with ocean-scale variation in migration schedules. Movement Ecology 12 : 22. https://doi.org/10.1186/s40462-024-00459-9

Walker, R.H. , Robinson, R.A. , Barimore, C.J. , Blackburn, J.R. , Barber, L.J. , Bugg, N.R. , McCambridge, H.E. , Grantham, M.J. , Griffin, B.M. , Leighton, K. & Schäfer, S. 2024. Bird ringing and nest recording in Britain and Ireland in 2021. Ringing & Migration 38 : 44—88. https://doi.org/10.1080/03078698.2023.2284510

Woodward, I.D., Thaxter, C.B. , Owen, E., Bolton, M., Ward, R.M. & Cook, A.S.C.P. 2024. The value of seabird foraging ranges as a tool to investigate the impact of offshore wind farms. Ocean and Coastal Management 254 : 107192. https://doi.org/10.1016/j.ocecoaman.2024.107192

Trustees’ Annual Report & Financial Statements 2024/25 | 37

SUMMARISED FINANCIAL STATEMENTS

FINANCIAL OVERVIEW

Overall, there was a net income deficit of £307k, (2023/24 £1,487k surplus). Following a record year in 2023/24, there was a £1,212k drop in legacy income. This was not unexpected given the unpredictable nature of this income stream. Other fundraising was £125k lower than 2023/24. This included a slight drop in membership income. In total, voluntary income formed 32% of total group income for the year (2023/24 44%). We aim to raise this to over 50% in the longer term. This was offset by increased income from contract work which rose by £651k (16%) to £4,618k (2023/24 £3,967k).

A total of £7,270k (2023/24 £6,215k) was spent during the year on carrying out, supporting and communicating ornithological research. Further increases in bond yields led to another reduction in the present value of the defined benefit pension obligation, taking the deficit to a comfortably manageable level.

The Board has a free reserves target range of three to four months’ running costs. These reserves are held against any unexpected falls in income or other unforeseen circumstances. Free reserves are total General funds less Tangible fixed assets less Designated funds. At 31 March 2025 these stood at £2,670k (2024: £3,112k), equivalent to 4.4 months’ running costs (2024: 6.0 months). The Board has earmarked the funds for the 2025 pension deficit recovery payment, IT infrastructure and hardware refresh, the Bird Atlas 2027—2031 , and other initiatives arising in response to the new strategy.

TRUSTEES’ STATEMENT

These are summarised accounts. To gain a full understanding of the financial affairs of the Trust please refer to the Annual Report and Accounts published on the BTO website or request a printed copy from the Director of Finance & Governance, BTO, The Nunnery, Thetford, Norfolk IP24 2PU.

The Annual Report and Accounts were approved by the Board on 27 August 2025 and will be submitted to the Registrar of Companies, the Charity Commission and the Office of the Scottish Charity Regulator. The auditor’s report by Helen Rumsey (FCA), Senior Statutory Auditor, Ensors, was unqualified.

SUMMARISED ACCOUNTS: 2024/25

		£’000	£’000
INCOME	2024/25		2023/24
			as restated
Donations and legacies		2,801	4,138
Charitable activities		4,618	3,967
Other tradingactivities		1,189	1,266
Investments		104	92
Total income & endowments		8,712	9,463
EXPENDITURE	2024/25		2023/24
Raisingfunds		1,735	1,783
Charitable activities		7,270	6,215
Other — defined benefitpension scheme		23	50
Total expenditure		9,028	8,048
Net income / expenditure		–316	1,415
Netgains on investments		9	72
Actuarialgain / loss on defined benefitpension	scheme	180	393
Net movement in funds		–127	1,880
Total funds brought forward		6,665	4,785
Total funds carried forward		6,538	6,665
REPRESENTED BY	2024/25		2023/24
Fixed assets		2,960	2,946
Net current assets		3,847	4,406
Creditors due after oneyear		–89	–100
Defined benefitpension liability		–180	–587
		6,538	6,665

38 | Trustees’ Annual Report & Financial Statements 2024/25

Trustees’ Annual Report & Financial Statements 2024/25 | 39

BOARD OF TRUSTEES AND MANAGEMENT

The British Trust for Ornithology Board of Trustees and Management 2025

Patron

HRH The Prince of Wales

President

F R Gardner OBE TD VR FRGS

Board of Trustees
Chair	Prof Z G Davies	2023-26
Honorary Treasurer	J E Miller FCCA	2023-26
Chair of Finance & Risk Committee	I Coucher	2022-25
Chair of Governance, Safeguarding & Inclusion	Dr G Ludhra	2025-28
Committee (Co-optee Board Member)
Chair of Regional Network Committee	S Metcalfe	2025-28
Chair of Ringing Committee	Dr L Wright	2022-25
Ordinary Board Members	D Buscall	2024-27
	E Dresser	2023-26
	R du Feu	2022-25
	S J Marquis	2020-27
	E Thornton	2023-26
	Prof S Willis	2024-27
	J M Ziff	2023-26
Vice Presidents	Dr F Barclay	2022-30
	Prof S Bearhop	2019-26
	D C Jardine	2020-27

Finance & Risk Committee

Chair I Coucher; J E Miller; J M Ziff.

Governance, Safeguarding & Inclusion Committee

Chair Dr G Ludhra; E Dresser, E Thornton.

Regional Network Committee

Chair S Metcalf ; H Crabtree; A Jarratt-Knock; E Tigwell.

Ringing Committee

Chair Dr L Wright; R du Feu; H Franklin; P Kirmond; L Hatton; J Lennon; S Vickers; R Walsh; Representatives : H James; E Smart.

Senior Leadership Team

Chief Executive Officer Prof J Vickery;

Director of Science Prof J W Pearce-Higgins; Director of Engagement Dr D I P Evans; Director of Finance & Governance, Company Secretary S D Bradfield ACA; Director of Information Services G N Hatt; Director Country Offices Dr C V Wernham; Director Head of People and Organisational Development S Knott.

40 | Trustees’ Annual Report & Financial Statements 2024/25

BOARD OF TRUSTEES AND MANAGEMENT

Past Presidents and Chairs

Presidents Chairs 1958-60 R C Homes 1933-39 The Right Hon. Lord Scone MP, 7th Earl of Mansfield and Mansfield 1961-64 C A Norris 1940-41 The Right Hon. Malcolm MacDonald MP 1965-68 R C Homes 1942-47 Dr A Landsborough Thomson CB OBE DSc 1969-72 I J Ferguson-Lees 1948 Dr E M Nicholson CB CVO 1973-76 R A O Hickling 1949 A W Boyd MC 1977-80 J M McMeeking MBE 1950 Sir Norman Kinnear 1981-84 S M Taylor 1951-56 Major-General H P W Houston 1985-89 J A Hancock OBE 1957 R C Homes 1990-93 R P Howard 1958-87 No Chair 1994-96 Sir William Wilkinson 1988-91 G H Green 1997-2001 Sir Frederick Holliday 1992-96 I C Castle 2002-05 Lord Blakenham 1996-2000 Dr H P Sitters 2006-13 Baroness Young of Old Scone 2001-04 A J Martin 2014-18 C G Packham 2005-08 Dr S Hunter 2019F R Gardner OBE TD VR FRGS 2009-13 Prof I Newton FRS OBE 2014-16 Prof A D Fox 2016-22 Prof J A Gill 2023Prof Z G Davies

Trustees’ Annual Report & Financial Statements 2024/25 | 41

TRUSTEES' ANNUAL REPORT

The British Trust for Ornithology Trustees’ Annual Report (incorporating the Strategic Report) For the Year Ended 31 March 2025

For the purposes of Section 162 of the Charities Act 2011 and the Directors’ Report for the purposes of Section 415 of the Companies Act 2006.

Objectives and Activities

Charitable Objects

The objects of the Trust, as set out in its Memorandum of Association are, for the benefit of the nation:

• (i) To promote, organise, carry on and encourage study and research and particularly field work for the advancement of knowledge in all branches of the Science of Ornithology.

• (ii) Permanently to preserve and protect lands and objects which by their natural features are suitable for the preservation and study of bird life and of fauna and flora generally.

Public Benefit

The trustees have complied with the duty in Section 17 of the Charities Act 2011 to have due regard to public benefit guidance published by the Charity Commission. The following paragraphs set out in detail the aims, activities and performance of the Trust, and the way in which they provide public benefit.

Objectives and Activities

The BTO’s purpose and public benefit is to deliver objective information and advice, through undertaking impartial research and analysis about birds, other wildlife and habitats, to advance the understanding of nature. We inform policies and evidence-based decisions that impact on the environment such that future generations can benefit from a healthy and wildlife-rich environment. The BTO does this by:

• Sustaining long-term extensive programmes and smaller scale intensive research to study the population trends, movements, breeding, survival, ecology and behaviour of wild birds;

• Encouraging, enthusing, training and supporting volunteers to take part in scientific studies;

• Bringing together professional scientists and volunteer birdwatchers in surveys of wildlife (particularly, but not exclusively, birds); and

• Analysing the data gathered through these studies, making information available to Government and other bodies, and publishing the results in the primary scientific literature and via the internet, the birdwatching and conservation press and the media more generally.

Strategic Report

The Strategic Report (Achievements and Performance, Plans for Future Periods) is contained in Part A of this document.

Principal Risks and Uncertainties

The trustees consider that the principal risks and uncertainties which could affect BTO’s ability to deliver its objectives in the short term are public expenditure reductions leading to reduced contract, grant and partnership funding, and in the medium to long term, inflation and the final salary pension scheme deficit. These are able to be mitigated through the continued growth strategy and careful cash management.

Financial Review

The Directors’ Report, the consolidated financial statements and the accompanying notes thereto comprise Part B of this document.

Overall, there was a net income deficit of £307k, (2023/24 £1,487k surplus). Following a record year in 2023/24, there was a £1,212k drop in legacy income. This was not unexpected given the unpredictable nature of this income stream. Other fundraising was £125k lower than 2023/24. This included a slight drop in membership income. In total voluntary income formed 32% of total group income for the year (2023/24 44%). We aim to raise this to over 50% in the longer term. This was offset by increased income from contract work which rose by £651k (16%) to £4,618k (2023/24 £3,967k).

42 | Trustees’ Annual Report & Financial Statements 2024/25

FOR THE YEAR ENDED 31 MARCH 2025

The British Trust for Ornithology Trustees’ Annual Report (incorporating the Strategic Report) - Continued For the Year Ended 31 March 2025

Financial Review Cont’d

A total of £7,270k (2023/24 £6,215k) was spent during the year on carrying out, supporting and communicating ornithological research. Further increases in bond yields led to another reduction in the present value of the defined benefit pension obligation, taking the deficit to a comfortably manageable level.

Reserves

The Board has a free reserves target range of 3 to 4 months’ running costs. These reserves are held against any unexpected falls in income or other unforeseen circumstances. Free reserves are total General funds less Tangible fixed assets less Designated funds. At 31 March 2025 these stood at £2,670k (2024: £3,112k), equivalent to 4.4 months’ running costs (2024: 6.0 months). The Board have earmarked the funds for the 2025 pension deficit recovery payment, IT infrastructure and hardware refresh, the Bird Atlas 2027-2031, and other initiatives arising in response to the new Strategy.

Structure, Governance and Management

Company number: 00357284 (England and Wales) Charity number: 216652 (England and Wales) SC039193 (Scotland) Registered Office: The Nunnery, Thetford, Norfolk IP24 2PU Principal Advisers: Auditors Ensors Accountants LLP, Connexions, 159 Princes Street, Ipswich IP1 1QJ Principal Bankers National Westminster Bank plc, 7 Cornhill, Bury St Edmunds, Suffolk IP33 1BQ Solicitors Browne Jacobson LLP, Castle Meadow Road, Nottingham NG2 1BJ Pensions Advisers Hughes Price Walker, Pembroke House, 15 Pembroke Rd, Clifton, Bristol BS8 3BA Investment Advisers The Progeny Group Ltd, 1 The Triangle, NG2 Business Park, Nottingham NG2 1AE Insurance Brokers One Broker, Discovery House, 4 Norwich Business Park, Whiting Road, Norwich, NR4 6DJ

Governing Document

The British Trust for Ornithology (known generally as the BTO) is a company limited by guarantee governed by its Memorandum and Articles of Association. It is registered as a charity with the Charity Commission and the Office of the Scottish Charity Regulator. Membership is open to any person whose application is approved by the Board upon payment of the requisite subscription. Members undertake to contribute up to £1 each in the event of an insolvent winding up, which represents the limit of their guarantee.

Trustees

The members of the Board are the directors of the charitable company under company law and the trustees for the purpose of charity law. Those serving during the year were as follows:

Prof Z G Davies	S J Metcalfe(appointed 1 January 2025)
D Buscall	J E Miller
I Coucher	E Thornton
E Dresser	Prof S Willis
R du Feu	Dr L Wright
Dr P Fitzpatrick (retired 31 December 2024)	J M Ziff
S J Marquis	Dr G Ludhra (co-optee board member – from 1 January 2025)

Trustees are nominated by the Board, on the recommendation of the Governance and Nominations Committee, following open advertisement, or by members and elected by the members at the Annual General Meeting each year, to serve from the following 1 January. The normal term of office is four years, with a limit of two consecutive terms. New trustees receive a comprehensive information pack and undergo induction to brief them on the BTO and their role as company directors and trustees.

Trustees’ Annual Report & Financial Statements 2024/25 | 43

TRUSTEES' ANNUAL REPORT

The British Trust for Ornithology Trustees’ Annual Report (incorporating the Strategic Report) - Continued For the Year Ended 31 March 2025

Organisation and Key Management Remuneration

The Board of Trustees is the governing body of the BTO. It meets at least four times a year. The Board is supported by the Finance & Risk Committee, Governance, Safeguarding & Inclusion Committee, Regional Network Committee and Ringing Committee. The day-to-day operational management of the BTO is delegated to the Senior Leadership Team, led by the Chief Executive Officer (CEO).

The salary of the CEO is determined on the basis of comparability to relevant benchmarks. The remuneration of all other staff is set according to a bespoke job evaluation scheme, benchmarked as appropriate. All salaries are subject to annual cost of living review. There is no bonus scheme.

Related Parties

The BTO’s wholly owned subsidiary, BTO Services Ltd, was established to undertake commercial activities to support the work of the BTO, and gifts its profits to the Trust. On 30 August 2017 BTO Services Ltd acquired the ring manufacturer Porzana Ltd. The net assets and activities of Porzana Ltd were subsequently hived up to BTO Services Ltd and it then became dormant. On 15 November 2019 BTO Services Ltd incorporated BTO Consulting Ltd which company is dormant. ‘Porzana’ and ‘BTO Consulting’ are trading names of BTO Services Ltd.

The BTO co-operates with many other charities, with government agencies and other bodies in pursuit of its objectives, as illustrated in Parts A and B of this document.

Volunteers

The Trust depends on the contributions of many thousands of volunteers who participate in BTO surveys and other activities. The Trust is greatly indebted to them, and especially to the Regional Representatives and other regional volunteers who organise so much activity at a local level. BTO volunteers contributed the equivalent of approximately 357,254 days of work in calendar year 2024 (2023: 284,181 days). The increase in 2024 is due to a change in the way the contribution made through BirdTrack has been calculated. This has resulted in a 70% increase in the estimate of volunteer hours to that scheme which is the largest single contributor to overall volunteering.

Risk Management

A risk register is maintained which identifies the significant risks faced by the BTO and the measures in place to manage and mitigate those risks. These are monitored by the Senior Leadership Team and regularly reviewed and amended as appropriate by the Finance & Risk Committee and the Board.

Fundraising Standards

BTO is registered with the Fundraising Regulator and follows the Fundraising Regulator’s Code of Fundraising Practice. All fundraising from individual giving is undertaken by BTO staff, and during the year we used the services of a specialist consultancy to help us research and approach charitable trusts and foundations. We have not received any complaints regarding our fundraising practices. We take all reasonable steps to treat supporters fairly and transparently, especially if we believe they may be in a vulnerable position.

44 | Trustees’ Annual Report & Financial Statements 2024/25

FOR THE YEAR ENDED 31 MARCH 2025

The British Trust for Ornithology Trustees’ Annual Report (incorporating the Strategic Report) For the Year Ended 31 March 2025

Investments

The Memorandum of Association permits the Trust to invest monies not immediately required for its purposes as the trustees see fit. The trustees’ investment policy is to maximise long term total return by investing in a combination of 40% high quality short-dated bonds and 60% globally diversified equities. The equities part of the portfolio is invested in a sustainable fund (see Note 10). Investment performance against benchmark was as follows:

	Portfolio	Benchmark
Year ended 31 March 2025	+3.04%	+4.03%
Since inception (28 August 2014)	+93.48%	+94.23%

Pensions

The Trust operates a Group Self-invested Personal Pension Scheme run by Aegon. Staff contribute to this defined contribution scheme at a minimum rate of 4% of salary, and the BTO contributes at a flat rate of 11%.

The Trust’s defined benefit pension scheme, a ‘final salary’ scheme, is closed. The last triennial actuarial valuation of the scheme was carried out as at 31 March 2024. At that date there was a net funding deficit of £1,613k and a funding level of 87%. A deficit recovery plan was subsequently agreed between the Board and the pension fund trustees, by which the shortfall would be made good by annual lump sum deficit repair payments spread over the years to 2031. The scheme was managed by Progeny Ltd up to 31 March 2025. From 1 April 2025 Hughes Price Walker took over scheme management.

Trustees’ Annual Report & Financial Statements 2024/25 | 45

TRUSTEES' ANNUAL REPORT

The British Trust for Ornithology Trustees’ Annual Report (incorporating the Strategic Report) - Continued For the Year Ended 31 March 2025

Statement of Board Members’ Responsibilities

The Board members are responsible, as Directors of the Company, for preparing the Annual Report (including the Strategic Report) and the financial statements in accordance with applicable law and United Kingdom Accounting Standards (United Kingdom Generally Accepted Accounting Practice).

Company law requires the Board members to prepare financial statements for each financial year, which give a true and fair view of the state of affairs of the charitable company and the group at the year end and of the incoming resources and application of resources, including the income and expenditure, of the charitable company and the group for the year. In preparing these financial statements, Board members are required to:

• select suitable accounting policies and then apply them consistently;

• observe the methods and principles in SORP (FRS 102);

• make judgements and estimates that are reasonable and prudent;

• state whether applicable UK Accounting Standards have been followed, subject to any material departures disclosed and explained in the financial statements; and

• prepare the financial statements on the going concern basis unless it is inappropriate to presume that the charitable company and the group will continue in operation.

Board members are responsible for keeping adequate accounting records that disclose with reasonable accuracy at any time the financial position of the charitable company and the group and enable them to ensure that the financial statements comply with the Companies Act 2006, the Charities and Trustee Investment (Scotland) Act 2005 and the Charities Accounts (Scotland) Regulations 2006 (as amended). They are also responsible for safeguarding the assets of the charitable company and the group and hence for taking reasonable steps for the prevention and detection of fraud and other irregularities.

Board members are responsible for the maintenance and integrity of the corporate and financial information included on the Trust's website. Legislation in the United Kingdom governing the preparation and dissemination of financial statements may differ from legislation in other jurisdictions.

In so far as Board members are aware:

• there is no relevant audit information of which the Trust’s auditors are unaware; and

• Board members have taken all steps that they ought to have taken to make themselves aware of any relevant audit information and to establish that the auditors are aware of that information.

Auditors

A resolution to appoint the auditors will be proposed at the Annual General Meeting under section 485 of the Companies Act 2006.

The Trustees’ Report (incorporating the Strategic Report) was approved by the Board as Directors and Trustees and authorised for issue on 27 August 2025.

Prof Z G Davies Chair

J E Miller FCCA Honorary Treasurer

46 | Trustees’ Annual Report & Financial Statements 2024/25

INDEPENDENT AUDITORS’ REPORT TO THE MEMBERS OF THE BRITISH TRUST OF ORNITHOLOGY

Independent Auditors’ Report to the Members of The British Trust for Ornithology

Opinion

We have audited the group financial statements of The British Trust for Ornithology (the ‘parent charitable company’) and its subsidiaries (the ‘group’) for the year ended 31 March 2025 which comprise the Consolidated Statement of Financial Activities, the Charity Statement of Financial Activities, the Consolidated Group and Charity Balance Sheets, the Consolidated Group and Charity Statement of Cash Flows, and notes to the financial statements, including a summary of significant accounting policies. The financial reporting framework that has been applied in their preparation is applicable law and United Kingdom Accounting Standards including FRS 102 “The Financial Reporting Standard applicable in the UK and Republic of Ireland” (United Kingdom Generally Accepted Accounting Practice).

In our opinion the financial statements:

• give a true and fair view of the state of the group’s and the parent charitable company’s affairs as at 31 March 2025

• and of the group’s and the parent charitable company’s incoming resources and application of resources, including its income and expenditure for the year then ended;

• have been properly prepared in accordance with United Kingdom Generally Accepted Accounting Practice; and

• have been prepared in accordance with the requirements of the Companies Act 2006, the Charities and Trustee Investment (Scotland) Act 2005 and regulations 6 and 8 of the Charities Accounts (Scotland) Regulations 2006 (as amended).

Basis for opinion

We conducted our audit in accordance with International Standards on Auditing (UK) (ISAs (UK)) and applicable law. Our responsibilities under those standards are further described in the Auditors’ responsibilities for the audit of the financial statements section of our report. We are independent of the group and parent charitable company in accordance with the ethical requirements that are relevant to our audit of the financial statements in the UK, including the FRC’s Ethical Standard, and we have fulfilled our other ethical responsibilities in accordance with these requirements. We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our opinion.

Conclusions relating to going concern

In auditing the group financial statements, we have concluded that the trustees' use of the going concern basis of accounting in the preparation of the financial statements is appropriate.

Based on the work we have performed, we have not identified any material uncertainties relating to events or conditions that, individually or collectively, may cast significant doubt on the group or parent charitable company's ability to continue as a going concern for a period of at least twelve months from when the financial statements are authorised for issue.

Our responsibilities and the responsibilities of the trustees with respect to going concern are described in the relevant sections of this report.

Other information

The other information comprises the information included in the annual report other than the group financial statements and our auditors’ report thereon. The trustees are responsible for the other information. Our opinion on the group financial statements does not cover the other information and, except to the extent otherwise explicitly stated in our report, we do not express any form of assurance conclusion thereon. In connection with our audit of the group financial statements, our responsibility is to read the other information and, in doing so, consider whether the other information is materially inconsistent with the financial statements or our knowledge obtained in the course of the audit, or otherwise appears to be materially misstated. If we identify such material inconsistencies or apparent material misstatements, we are required to determine whether there is a material misstatement in the financial statements or a material misstatement of the other information. If, based on the work we have performed, we conclude that there is a material misstatement of this other information, we are required to report that fact.

We have nothing to report in this regard.

Opinion on other matters prescribed by the Companies Act 2006

In our opinion, based on the work undertaken in the course of the audit:

• the information given in the Trustees’ Annual Report, which includes the Directors’ Report and the Strategic Report prepared for the purposes of company law, for the financial year for which the group financial statements are prepared is consistent with the group financial statements; and

• the Strategic Report and the Directors’ Report included within the Trustees’ Annual Report has been prepared in accordance with applicable legal requirements.

Trustees’ Annual Report & Financial Statements 2024/25 | 47

INDEPENDENT AUDITORS’ REPORT TO THE MEMBERS OF THE BRITISH TRUST OF ORNITHOLOGY

Independent Auditors’ Report to the Members of The British Trust for Ornithology - Continued

Matters on which we are required to report by exception

In the light of our knowledge and understanding of the group and the parent charitable company and their environment obtained in the course of the audit, we have not identified material misstatements in the Strategic Report or the Directors’ Report included within the Trustees’ Annual Report.

We have nothing to report in respect of the following matters in relation to which the Companies Act 2006 and the Charities Accounts (Scotland) Regulations 2006 (as amended) require us to report to you if, in our opinion:

• adequate and proper accounting records have not been kept by the parent charitable company, or returns adequate for our audit have not been received from branches not visited by us; or

• the parent charitable company’s financial statements are not in agreement with the accounting records or returns; or

• certain disclosure of trustees’ remuneration specified by law are not made; or

• we have not received all the information and explanations we require for our audit; or

• the trustees were not entitled to prepare the financial statements in accordance with the small companies regime and take advantage of the small companies’ exemptions in preparing the trustees’ report.

Responsibilities of Board Members

As explained more fully in the Statement of Board Members’ Responsibilities set out on page B9, the trustees (who are also the directors of the British Trust for Ornithology for the purposes of company law) are responsible for the preparation of the group financial statements and for being satisfied that they give a true and fair view, and for such internal control as the trustees determine is necessary to enable the preparation of group financial statements that are free from material misstatement, whether due to fraud or error.

In preparing the group financial statements, the trustees are responsible for assessing the group’s and parent charitable company’s ability to continue as a going concern, disclosing, as applicable, matters related to going concern and using the going concern basis of accounting unless the trustees either intend to liquidate the group or the parent charitable company or to cease operations, or have no realistic alternative but to do so.

Auditors’ responsibilities for the audit of the financial statements

We have been appointed as auditor under section 44(1)(c) of the Charities and Trustee Investment (Scotland) Act 2005 and under the Companies Act 2006 and report in accordance with the Acts and relevant regulations made or having effect thereunder.

Our objectives are to obtain reasonable assurance about whether the group financial statements as a whole are free from material misstatement, whether due to fraud or error, and to issue an auditors’ report that includes our opinion. Reasonable assurance is a high level of assurance, but is not a guarantee that an audit conducted in accordance with ISAs (UK) will always detect a material misstatement when it exists. Misstatements can arise from fraud or error and are considered material if, individually or in the aggregate, they could reasonably be expected to influence the economic decisions of users taken on the basis of these financial statements.

Irregularities, including fraud, are instances of non-compliance with laws and regulations. We design procedures in line with our responsibilities, outlined above, to detect material misstatements in respect of irregularities, including fraud. The extent to which our procedures are capable of detecting irregularities, including fraud, is detailed below.

Our audit was designed, after obtaining sufficient and appropriate knowledge and understanding of the group and parent charitable company, its charitable nature, its income streams and the sector operated within. We undertook an assessment of the control environment and the systems and procedures put in place by the senior management team, combined with our detailed audit testing and supportive analytical work, to obtain reasonable assurance about whether the group financial statements as a whole are free from material misstatement due to fraud. Our work has included considering areas of higher risk of fraud, including transactions with related parties, revenue recognition and areas where there is a risk of management override of systems and controls.

To address the risk of fraud we performed the following audit procedures:

• Assessment of key accounting estimates within the group financial statements in order to assess their reasonableness and determine whether there is any bias in management’s estimates.

48 | Trustees’ Annual Report & Financial Statements 2024/25

INDEPENDENT AUDITORS’ REPORT TO THE MEMBERS OF THE BRITISH TRUST OF ORNITHOLOGY

Independent Auditors’ Report to the Members of The British Trust for Ornithology - Continued

• All team members were informed of the relevant laws and regulations and potential fraud risks at the planning stage and reminded to remain alert to any indications of fraud or non-compliance.

• Enquiring of management whether there have been any alleged, suspected or actual instances of fraud during the year.

• Enquiring of management and those charged with governance whether there have been any actual or potential litigation or claims.

• Reviewing correspondence with relevant legal authorities.

• Reviewing legal expense accounts for any indicators of litigation or claims.

• Review of journal entries and other adjustments for appropriateness and evaluating the rationale of any transactions outside the normal course of business.

A further description of our responsibilities for the audit of the group financial statements is located on the Financial Reporting Council’s website at www.frc.org.uk/auditorsresponsibilities. This description forms part of our auditors’ report.

Use of our report

This report is made solely to the parent charitable company’s members, as a body, in accordance with Chapter 3 of Part 16 of the Companies Act 2006 and to the charitable company’s trustees, as a body, in accordance with regulation 10 of the Charities Accounts (Scotland) Regulations 2006 (as amended). Our audit work has been undertaken so that we might state to the parent charitable company’s members and trustees those matters we are required to state to them in an auditors’ report and for no other purpose. To the fullest extent permitted by law, we do not accept or assume responsibility to anyone other than the parent charitable company, the parent charitable company’s members as a body and its trustees as a body, for our audit work, for this report, or for the opinions we have formed.

Helen Rumsey, Senior Statutory Auditor For and on behalf of Ensors Accountants LLP Connexions 159 Princes Street Ipswich IP1 1QJ

BTO Annual Report 2024/25 B11

Trustees’ Annual Report & Financial Statements 2024/25 | 49

FINANCIAL STATEMENTS

The British Trust for Ornithology Consolidated Statement of Financial Activities (Including Income and Expenditure Account) for the Year Ended 31 March 2025

Note Income and endowments from: Donations and legacies 3 Charitable activities 3 Other trading activities 3 Investments 3 Total income and endowments Expenditure on: Raising funds 4 Charitable activities 4 Other – Amounts recognised as expenditure on defined benefit pension scheme 23 Total expenditure Net income/(expenditure) before net gain/(loss) on investments Net gain/(loss) on investments 10 Net income/ (expenditure) Transfers between funds 16,17 Other recognised gains/(losses): Actuarial gain/(loss) on defined benefit pension scheme 23 Net movement in funds Reconciliation of funds Total funds brought forward Total funds carried forward 16,17	Unrestricted Funds £’000 2,296 4,607 1,189 92 8,184 1,718 6,664 23 8,405 (221) 9 (212) (89) 180 (121) 5,453 5,332	Restricted Funds £’000 505 11 - 12 528 17 606 - 623 (95) - (95) 89 - (6) 1,212 1,206	Total 2025 £’000 2,801 4,618 1,189 104	Total 2024 As restated £’000 4,138 3,967 1,266 92
			8,712	9,463
			1,735 7,270 23	1,783 6,215 50
			9,028	8,048
			(316) 9	1,415 72
			(307) - 180	1,487 - 393
			**(127) **	1,880
			6,665	4,785
			6,538	6,665

The Statement of Financial Activities includes all gains and losses recognised during the year. All income and expenditure derives from continuing activities.

The notes on pages B16 to B35 form part of these financial statements. The notes on pages 54 to 75 form part of these financial statements

50 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Charity Statement of Financial Activities (Including Income and Expenditure Account) for the Year Ended 31 March 2025

Note Income and endowments from: Donations and legacies 3 Charitable activities 3 Other trading activities 3 Investments 3 Total income and endowments Expenditure on: Raising funds 4 Charitable activities 4 Other – Amounts recognised as expenditure on defined benefit pension scheme 23 Total expenditure Net income/(expenditure) before net gain/(loss) on investments Net gain/(loss) on investments 10 Net income/ (expenditure) Transfers between funds Other recognised gains/(losses): Actuarial gain/(loss) on defined benefit pension scheme 23 Net movement in funds Reconciliation of funds Total funds brought forward Total funds carried forward 16,17	Unrestricted Funds £’000 2,556 4,607 690 92 7,945 1,475 6,668 23 8,166 (221) 9 (212) (89) 180 (121) 5,453 5,332	Restricted Funds £’000 505 11 - 12 528 17 606 - 623 (95) - (95) 89 - (6) 1,212 1,206	Total 2025 £’000 3,061 4,618 690 104 8,473 1,496 7,270 23 8,789 (316) 9 (307) - 180 (127) 6,665 6,538	Total 2024 As restated £’000 4,346 3,967 741 92
				9,146
				1,451 6,230 50
				7,731
				1,415 72
				1,487 - 393
				1,880
				4,785
				6,665

The Statement of Financial Activities includes all gains and losses recognised during the year. All income and expenditure derives from continuing activities.

The notes on pages 54 to 75 form part of these financial statements The notes on pages B16 to B35 form part of these financial statements.

Trustees’ Annual Report & Financial Statements 2024/25 | 51

FINANCIAL STATEMENTS

The British Trust for Ornithology Consolidated Group and Charity Balance Sheets as at 31 March 2025

Note Fixed assets Tangible assets 9 Investments 10 Current assets Stocks 11 Debtors 12 Cash at bank and in hand Creditors: Amounts falling due within one year 13 Net current assets Total assets less current liabilities Creditors: Amounts falling due after one year 14 Net assets excluding defined benefit pension liability Defined benefit pension liability 23 Net assets/(liabilities) including defined benefit pension liability 18 Represented by: Restricted funds 16 Unrestricted funds excluding Pension reserve Pension reserve 17 17 Total funds 18	Group 2025 £’000 2,431 529 2,960 248 1,082 4,967 6,297 (2,450) 3,847 6,807 (89) 6,718 (180) 6,538 1,206 5,512 (180) 6,538	Group 2024 As restated £’000 2,427 519 2,946 244 2,270 4,132 6,646 (2,240) 4,406 7,352 (100) 7,252 (587) 6,665 1,212 6,040 (587) 6,665	Charity 2025 £’000 2,431 529 2,960 - 1,309 4,853 6,162 (2,315) 3,847 6,807 (89) 6,718 (180) 6,538 1,206 5,512 (180) 6,538	Charity 2024 As restated £’000 2,427 519
				2,946
				- 2,511 4,024
				6,535 (2,129)
				4,406
				7,352 (100)
				7,252 (587)
				6,665
				1,212 6,040 (587)
				6,665

Approved by the Board and authorised for issue on 27 August 2025 and signed on its behalf by:

Chair Prof Z G Davies Honorary Treasurer J E Miller FCCA

Company registration number 00357284

The notes on pages B16 to B35 form part of these financial statements. The notes on pages 54 to 75 form part of these financial statements

52 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Consolidated Group and Charity Statement of Cash Flows For the Year Ended 31 March 2025

Note Net cash inflow / (outflow) from operating activities 20 Cash flow from investing activities Payments to acquire tangible fixed assets 9 Proceeds from the sale of tangible fixed assets Investment income received Net cash flow from investing activities Net increase/(decrease) in cash for the year Cash at bank and in hand at 1 April Cash at bank and in hand at 31 March Analysis of Cash at Bank and in Hand This comprises: Bank current accounts and cash in hand Bank deposits Cash at bank and in hand at 31 March	Group 2025 £’000 755 (24) - 104 80 835 4,132 4,967 2025 £’000 814 4,153 4,967		Group 2024 £’000 514 (12) - 92 80 594 3,538 4,132 2024 £’000 327 3,805 4,132		Charity 2025 £’000 749 (24) - 104 80 829 4,024 4,853 2025 £’000 700 4,153 4,853		Charity 2024 £’000 491
							(12) - 92
							80
							571 3,453
							4,024
							2024 £’000 219 3,805 4,024

Bank deposits carry variable rates of interest.

The notes on pages B16 to B35 form part of these financial statements. The notes on pages 54 to 75 form part of these financial statements

Trustees’ Annual Report & Financial Statements 2024/25 | 53

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements For the Year Ended 31 March 2025

1. ACCOUNTING POLICIES

a) Accounting Convention

The charity constitutes a public benefit entity as defined by FRS 102. The financial statements have been prepared in accordance with Accounting and Reporting by Charities: Statement of Recommended Practice applicable to charities preparing their accounts in accordance with the Financial Reporting Standard applicable in the UK and Republic of Ireland (FRS 102) (SORP (FRS102)) effective 1 January 2019, the Charities Act 2011, the Charities and Trustee Investment (Scotland) Act 2005, the Charities Accounts (Scotland) Regulations 2006, the Companies Act 2006 and UK Generally Accepted Practice as it applies from 1 January 2015.

The financial statements are prepared in pounds sterling (rounded to the nearest thousand) which is the functional currency of the charitable company and the group.

The charity operates on a weekly basis and the Financial Statements have been made up to 30 March 2025, being the last Sunday in March.

b) Going Concern

The trustees have prepared the financial statements on a going concern basis under the historical cost convention, modified to include certain items at fair value. In their opinion the pension scheme deficit does not give rise to material uncertainties that could cast doubt upon the appropriateness of this policy.

c) Group Financial Statements

These financial statements consolidate the results of the charity and its wholly owned trading subsidiary BTO Services Limited on a line-by-line basis.

d) Income

Income from donations, gifts and legacies is recognised immediately when received in cash and as receivable where there is entitlement, the amount can be measured reliably, and it is probable that the income will be received.

Income from charitable activities includes income receivable under contracts which is recognised as earned as the related work is performed. Income from grant funding supporting charitable activities is recognised where there is entitlement, probability of receipt, and the amount can be measured with sufficient reliability.

Income is deferred when it is received in advance of the services it relates to. Life membership income is released to the Statement of Financial Activities in equal instalments over ten years.

Income from commercial activities of the trading subsidiary is recognised as earned as the related goods and services are provided.

Investment income, sponsorship and royalty income and membership subscription income are recognised on a receivable basis.

e) Expenditure

Expenditure is recognised when a liability is incurred. Costs are allocated directly to activity cost categories. The cost of holiday pay not taken at the year end is accrued.

Costs of raising funds are those incurred in attracting voluntary income, including membership subscriptions, in carrying out trading activities, and in receiving royalties and sponsorship income.

54 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

Costs of charitable activities include those incurred on scientific research contracts, and on allocated and restricted fund research work. They also include volunteer surveyor support and science communication costs.

Governance costs include those incurred in the governance of the charity and the safeguarding of its assets, and are primarily associated with constitutional and statutory requirements.

Support costs include central functions and have been allocated to activity cost categories on a staff cost basis.

VAT is reclaimed on allowable expenses under the Business/Non-Business and the partial exemption rules. Where not reclaimable it is included within expenses.

f)

Tangible Fixed Assets

Individual assets costing £1k or more are initially capitalised at cost. Tangible fixed assets (except freehold property and land) are depreciated on a straight line basis over their estimated useful lives as follows:

) are depreciated on a straight line basis	over their estimated usef
Asset Category	Annual Rate
Furniture and Equipment	25%
Computer Equipment	25%
Motor Vehicles	25%

The freehold property is stated at fair value under the revaluation model using sufficiently regular revaluations to ensure that the carrying amount does not differ materially from the fair value at the reporting date. Revaluations are performed every five years, or as the trustees consider necessary, by qualified external valuers. The increase or decrease on revaluation is credited or charged to the fund holding the asset. The property is not depreciated as it is considered to have an indefinite remaining useful life.

At each reporting end date, the trustees review the carrying amounts of the tangible assets to determine whether there is any indication that those assets have suffered an impairment loss. If any such indication exists, the recoverable amount of the asset is estimated in order to determine the extent of the impairment loss (if any).

g) Investments

Investments are recognised initially at fair value which is normally the transaction price excluding transaction costs. Subsequently, they are measured at fair value with changes recognised in ‘Net gain/(loss) on investments’ in the Statement of Financial Activities if the shares are publicly traded or their fair value can otherwise be measured reliably. Other investments are measured at cost less impairment.

h) Stock

Stock is valued at the lower of cost and net realisable value. Net realisable value is based on estimated selling price less further costs to completion and sale. Cost is calculated on a first in first out basis.

i) Debtors and creditors falling due within one year

Debtors and creditors with no stated interest rate and falling due within one year are recorded at transaction price. Any losses arising from impairment are recognised in expenditure.

j) Financial instruments

The group only has financial assets and liabilities that qualify as basic financial instruments, such as debtors and creditors with no stated interest rate and payable within one year, which are recorded at transaction price. Any losses arising from impairment are recognised as expenditure in the Statement of Financial Activities.

Trustees’ Annual Report & Financial Statements 2024/25 | 55

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

k) Foreign Currency Translation

Monetary assets and liabilities denominated in foreign currencies are translated into pounds sterling at the rates of exchange ruling at the balance sheet dates. Transactions in foreign currencies are recorded at the rate ruling at the transaction date. All exchange differences are taken to the Statement of Financial Activities.

l) Funds Structure

The Trust has a number of restricted funds to account for situations where funds have been raised for a specific purpose. All other funds are unrestricted funds. Where the trustees intend to use part of the unrestricted funds to provide longer-term funding for BTO projects and core activities, designated funds are set up to reflect this. A Pension reserve fund has been created so that movements and balances relating to the defined benefit pension scheme valuations can be separately identified. The funds in each of these categories are disclosed in Notes 16 and 17.

m) Retirement Benefits

The defined benefit pension scheme provides benefits for staff based on final pensionable salary. The scheme was closed to future accrual with effect from 1 April 2013. The assets of the scheme are held separately from those of the Trust, being invested with independent fund managers and are measured at fair value with changes recognised in the Statement of Financial Activities as set out in Note 23. Defined benefit pension liabilities are measured using the projected unit cost method and discounted at the current rate of return on a high quality corporate bond of equivalent term and currency to the liability. Under FRS 102, any net liability arising based on these valuations is the best estimate of the present value of the actual amounts to be paid out of the scheme, less the fair value of the scheme assets. The net of the interests on the scheme assets and liabilities is charged to the Statement of Financial Activities. Past service costs are recognised as expenditure when a liability is incurred and are charged to the Statement of Financial Activities. Actuarial gains and losses are recognised in the Statement of Financial Activities.

The Trust as employer also makes payments in respect of employees' own defined contribution schemes, through a group self-invested personal pension arrangement. For these schemes, the amount charged to the Statement of Financial Activities in respect of pension costs is the contributions payable in the year. Differences between contributions payable in the year and contributions actually paid are included as either accruals or prepayments in the Balance Sheet.

n) Judgements and key sources of estimation uncertainty

In the application of the group and parent charitable company's accounting policies, the trustees are required to make judgements, estimates and assumptions about the carrying amount of assets and liabilities that are not readily apparent from other sources. The estimates and associated assumptions are based on historical experience and other factors that are considered to be relevant. Actual results may differ from these estimates.

The estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognised in the year in which the estimate is revised where the revision affects only that year, or in the year of the revision and future years where the revision affects both the current and future years.

Key sources of estimation uncertainty

The estimates and assumptions which have a significant risk of causing a material adjustment to the carrying amount of assets and liabilities are as follows:

Percentage completion on contracts

The degree of completion on the contracts is an estimate by the relevant project manager. This estimate relies on their professional opinion on the level of work completed in the whole contract, which impacts the level of income recognised, accrued and deferred. These estimates are reviewed by the Senior Leadership Team on a regular basis.

56 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

n) Judgements and key sources of estimation uncertainty (continued)

Defined benefit pension scheme

The group has a defined benefit pension scheme which is closed to future accrual. The valuation of the defined benefit pension obligation necessarily involves a calculation which depends on the expected future outflow of economic benefits that the group expects to make to satisfy this obligation. The calculation depends on a number of factors such as the methodology, discount rate and mortality assumptions used. The group use a qualified independent actuary to assist in preparing the necessary calculation in accordance with the requirements of FRS102.

Property valuation

The Nunnery is valued at fair value by the directors with reference to recent property transactions and their knowledge of the site. The directors obtain third party valuations at regular intervals to ensure that the fair value of the property is kept up to date.

o) Leases

Rentals payable under operating leases, including any lease incentives received, are charged to profit or loss on a straight line basis over the term of the relevant lease except where another more systematic basis is more representative of the time pattern in which economic benefits from the leased asset are consumed.

p)

Employee benefits

The costs of short-term employee benefits are recognised as a liability and an expense unless those costs are required to be recognised as part of the cost of stock or fixed assets. The cost of any unused holiday entitlement is recognised in the year in which the employee’s services are received. Termination benefits are recognised immediately as an expense when the charity is demonstrably committed to terminate the employment of an employee or to provide termination benefits.

q) Cash at bank and in hand

Cash at bank and in hand are basic financial assets and includes cash in hand, deposits with banks, other shortterm liquid investments with original maturities of three months or less, and bank overdrafts.

r) Legacies

Legacy receipts are recognised when there has been grant of probate, the executors have established that there are sufficient assets in the estate, after settling any liabilities, to pay the legacy, any conditions attached to the legacy are either within the control of the Trust or have been met, and the amount receivable is determined.

2. MEMBERS' LIABILITY

Under the Memorandum of Association of the Trust, members are required to undertake to contribute to the assets of the Trust in the event of its being wound up while they are members, and within one year after they cease to be members, for payment of the debts and liabilities of the Trust contracted whilst they were still members, and of the costs, charges and expenses of winding up, such amount as may be required but not exceeding £1 each. This represents the limit of their guarantee to the company.

Trustees’ Annual Report & Financial Statements 2024/25 | 57

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

3. ANALYSIS OF INCOME

Donations and legacies Membership subscriptions & donations Individual donations Corporate & trust donations & grants Legacies Charitable activities Core surveys - JNCC Partnership Core surveys - Other Other surveys & research - Contract funded Research communication General volunteer survey support Nunnery Lakes Reserve Other trading activities Ringing & tagging sales Publications & general sales Corporate sponsorship & royalties Consultancy Data-related sales Other Income from charges to subsidiary Investment income Bank interest receivable Analysis by fund type Donations and legacies Unrestricted Restricted Charitable activities Unrestricted Restricted Other trading activities Unrestricted Restricted Investment income Unrestricted Restricted	Group 2025 £’000 1,005 654 343 799 2,801 1,418 56 2,909 109 102 24 4,618 448 22 61 419 237 2 - 1,189 104 Group 2025 £’000 2,296 505 2,801 4,607 11 4,618 1,189 - 1,189 92 12 104	Group 2024 £’000 1,030 668 429 2,011 4,138 1,358 37 2,376 77 96 23 3,967 491 30 26 558 156 5 - 1,266 92 Group 2024 £’000 3,508 630 4,138 3,929 38 3,967 1,266 - 1,266 81 11 92	Charity 2025 £’000 1,005 654 603 799 3,061 1,418 56 2,909 109 102 24 4,618 - - - - - 2 688 690 104 Charity 2025 £’000 2,556 505 3,061 4,607 11 4,618 690 - 690 92 12 104	Charity 2024 As restated £’000 1,030 668 637 2,011
				4,346
				1,358 37 2,376 77 96 23
				3,967
				- - - - - 5 736
				741
				92 Charity 2024 As restated £’000 3,716 630
				4,346
				3,929 38
				3,967
				741 -
				741
				81 11
				92

58 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

4. ANALYSIS OF EXPENDITURE

Raising funds Donations and legacies Membership subscriptions & donations Individual donations Corporate & trust donations & grants Legacies Other trading activities Ringing & tagging costs Publications & general costs Corporate sponsorship & royalties Consultancy Data-related costs Other Costs recharged to subsidiary Charitable activities Core surveys - JNCC Partnership Core surveys - Other Other surveys & research - Voluntary funded Other surveys & research - Contract funded Research communication General volunteer survey support Nunnery Lakes Reserve	Group 2025 £’000 310 304 85 120 819 456 26 - 290 137 7 - 916 1,735 2,054 280 830 3,018 797 246 45 7,270	Group 2024 As restated £’000 306 262 52 96 716 474 25 1 453 113 1 - 1,067 1,783 1,816 313 791 2,258 777 215 45 6,215	Charity 2025 £’000 310 304 85 120 819 - - - - - - 677 677 1,496 2,054 280 830 3,018 797 246 45 7,270	Charity 2024 £’000 306 262 52 96
				716
				- - - - - - 735
				735
				1,451
				1,817 313 791 2,272 777 215 45
				6,230

Analysis by fund type Raising funds Unrestricted Restricted Charitable activities Unrestricted Restricted	Group 2025 £’000 1,718 17 1,735 6,664 606 7,270	Group 2024 As restated £’000 1,783 - 1,783 5,488 727 6,215	Charity 2025 £’000 1,479 17 1,496 6,664 606 7,270	Charity 2024 £’000 1,451 -
				1,451
				5,503 727
				6,230

Trustees’ Annual Report & Financial Statements 2024/25 | 59

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

5. NET INCOME / (EXPENDITURE) Net income for the year is stated after (crediting)/charging: Auditors’ remuneration: Audit of the charity’s annual accounts Audit of the trading subsidiary’s annual accounts Audit of the charity’s defined benefit pension scheme Depreciation (Note 9) (Profit)/loss on disposals of fixed assets 6. STAFF COSTS Wages and salaries Social security costs Defined contribution pension plan costs (Note 23) Expenditure recognised on defined benefit pension scheme (Note 23) The number of employees whose emoluments exceeded £60,000 fell within the following bands: £70,001 - £80,000 £60,001 - £70,000	2025 £’000 22 10 3 19 1 Group and Charity 2025 £’000 5,319 490 560 23 6,392 2025 1 5	2024 £’000 21 8 3 18 -
		Group and Charity 2024 £’000 4,595 412 480 50
		5,537
		2024 1 4

The emoluments of the CEO for the year were £81k (2024 £80k), with the same pension and other benefits as were applicable to all other staff. The total remuneration including social security costs and pension contributions of the Senior Leadership Team was £553k (2024: £529k). Trustees receive no remuneration. Trustees made donations totalling less than £1k during the year (2024 less than£1k). There were no other related party transactions requiring disclosure. Other expenses were reimbursed to trustees as follows:

		2025		2024
		£’000		£’000
Travel and subsistence		1		1
Average numbers of staff and full time equivalents (FTE)
		2025		2024
	No	FTE	No	FTE
Permanent posts	159	145.3	148	133.6
Seasonal fieldworkers	4	1.0	7	1.6
	163	146.3	155	135.2

60 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

7. TOTAL EXPENDITURE

. TOTAL EXPENDITURE
Raising funds Charitable activities Other – Amounts recognised as expenditure on defined benefit pension scheme	Direct costs £’000 1,551 6,497 23 8,071	Support costs £’000 184 773 - 957	2025 Total £’000 1,735 7,270 23 9,028	2024 Total As restated £’000 1,783 6,215 50
				8,048

8. SUPPORT COSTS

Raising funds Charitable activities	Premises £’000 2 10 12	IT & Office Services £’000 9 37 46	People & OrgDev £’000 76 320 396	Manage- ment & Finance £’000 81 338 419	Govern- ance £’000 16 68 84	2025 Total £’000 184 773 957	2024 Total £’000 205 720
							925

All support costs are apportioned on a staff cost basis.

Governance costs include auditors’ remuneration, the meeting expenses of the Board and its committees, and the staff cost of servicing those meetings.

9. TANGIBLE FIXED ASSETS - GROUP

Cost or valuation at 1 April 2024 Additions Disposals At 31 March 2025 Depreciation at 1 April 2024 Depreciation charge Disposals At 31 March 2025 Net book value at 31 March 2025 Net book value at 1 April 2024	Freehold Property and Land £’000 2,400 - - 2,400 - - - - 2,400 2,400	Furniture and Equipment £’000 191 - (37) 154 186 2 (37) 151 3 5	Computer Equipment £’000 448 24 (124) 348 427 16 (123) 320 28 21	Motor Vehicles £’000 92 - - 92 91 1 - 92 - 1	Total £’000 3,131 24 (161)
					2,994
					704 19 (160)
					563
					2,431
					2,427

Trustees’ Annual Report & Financial Statements 2024/25 |

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

9. TANGIBLE FIXED ASSETS - CHARITY

Cost or valuation at 1 April 2024 Additions Disposals At 31 March 2025 Depreciation at 1 April 2024 Depreciation charge Disposals At 31 March 2025 Net book value at 31 March 2025 Net book value at 1 April 2024	Freehold Property and Land £’000 2,400 - - 2,400 - - - - 2,400 2,400	Furniture and Equipment £’000 187 - (37) 150 182 2 (37) 147 3 5	Computer Equipment £’000 448 24 (124) 348 427 16 (123) 320 28 21	Motor Vehicles £’000 92 - - 92 91 1 - 92 - 1	Total £’000 3,127 24 (161)
					2,990
					700 19 (160)
					559
					2,431
					2,427

The Nunnery and Nunnery Lakes Reserve, the freehold property and land owned and occupied by The British Trust for Ornithology, were valued by qualified external valuers, Fenn Wright Chartered Surveyors, on 31 March 2022 on the basis of fair value, at £2,400k. The trustees have considered the condition and value of the freehold property at the year end and believe there to have been no material change since the last external valuation in March 2022.

On an historical cost basis, the freehold property and land would have been included at a cost and net book value of £2,284k (2024: £2,284k).

62 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

10. INVESTMENTS

The Group

Listed Investment Funds

Birds in Trust Fund Dimensional Global Short Dated Bond Dimensional Global Sustainability Core Equity Wrap Cash General Funds Dimensional Global Short Dated Bond Dimensional Global Sustainability Core Equity Wrap Cash	Market value 1 April 2024 £’000 76 152 4 232 93 188 6 287 519	Disposals £’000 - - - - - - - - -	Additions £’000 - - - - - - - - -	Gain/(loss) £’000 - 4 - 4 - 5 - 5 9	Market value 31 March 2025 £’000 76 156 4
					236
					93 194 6
					293
					529

On an historical cost basis, the investments would have been included at £298k (2024: £298k).

The Charity

Listed Investment Funds as above Fixed asset unlisted investments -BTO Services Ltd	2025 £’000 529 - 529	2024 £’000 519 -
		519

The Trust wholly owns its subsidiary undertaking, BTO Services Ltd, which is incorporated in England & Wales, company registration number 02907282. This company operates to promote the work of The British Trust for Ornithology by undertaking commercial activities to support such work. The aggregate value of the share capital and reserves at 31 March 2025 was £100 (2024: £100) and the company reported a £nil result after profit distributions made under a Deed of Covenant for the year (2024: £nil). The value of the investment in the subsidiary undertaking is £100 (2024: £100) under the equity method of valuation.

The following is a summarised statement of income for the subsidiary for the financial year:

Turnover Cost of sales Gross profit Net administrative expenses Net profit before payment under Deed of Covenant	2025 £’000 1,187 (870) 317 (63) 254	2024 As restated £’000 1,261 (992)
		269 (61)
		208

Turnover of the subsidiary includes sales to overseas markets of £249k (2024: £192k).

Trustees’ Annual Report & Financial Statements 2024/25 | 63

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

10. INVESTMENTS (Continued)

BTO Services Ltd has two dormant wholly owned subsidiaries, both registered in England and Wales, and with Registered Office at The Nunnery, Thetford, Norfolk IP24 2PU, Porzana Ltd Company No.04175071 and BTO Consulting Ltd Company No.12317596.

11. STOCKS The Group Finished goods, goods for resale and materials	2025 £’000 2024 As restated £’000 248 244

The Charity

The charity holds no trading stock.

12. DEBTORS The Group Trade and contract debtors Taxes recoverable Prepayments Accrued income The Charity Trade and contract debtors Amounts due from Group undertakings Taxes recoverable Prepayments Accrued income	2025 £’000 569 61 116 336 1,082 2025 £’000 412 479 61 114 242 1,309	2024 £’000 1,503 22 123 622
		2,270
		2024 As restated £’000 1,257 522 22 121 589
		2,511

64 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

13. CREDITORS – AMOUNTS FALLING DUE WITHIN ONE YEAR

The Group Trade creditors Taxes and Social security costs Other creditors Accruals Deferred income The Charity Trade creditors Taxes and Social security costs Other creditors Accruals Deferred income 14. CREDITORS – AMOUNTS FALLING DUE AFTER ONE YEAR The Group Deferred income The Charity Deferred income 15. DEFERRED INCOME RECONCILIATION The Group Opening balance at 1 April Amount released to income Amount deferred in year Closing balance at 31 March The Charity Opening balance at 1 April Amount released to income Amount deferred in year Closing balance at 31 March	2025 £’000 460 298 153 157 1,382 2,450 2025 £’000 404 278 151 145 1,337 2,315 2025 £’000 89 2025 £’000 89 2025 £’000 1,490 (2,404) 2,385 1,471 2025 £’000 1,438 (2,350) 2,337 1,425	2024 £’000 309 288 63 190 1,390
		2,240
		2024 £’000 265 288 61 177 1,338
		2,129
		2024 £’000 100
		2024 £’000 100
		2024 £’000 1,673 (2,271) 2,088
		1,490
		2024 £’000 1,598 (1,206) 2,046
		1,438

Trustees’ Annual Report & Financial Statements 2024/25 | 65

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

16. RESTRICTED FUNDS

The Group and the Charity

The funds of the group and the charity include restricted funds comprising the following balances of donations and appeal monies given for specific purposes. The opening and closing fund balances for the group and the charity are identical.

As at 31 March 2025

Atlas Beyond Maps Appeal Northern Ireland Fund Dilys Breese Fund Migration Fund Nightingale Appeal Swallow Appeal Young Scientists’ Fund Garden Research Fund Out of Africa Fund Thrush Fund Curlew Appeal Arctic Skua Fund BTO Wales Fund Sound Approach Fund Tasso Leventis Fund Spotted Flycatcher Appeal Chaffinch Seabird Appeal Urban Appeal BBS Appeal Rhodes Training Fund Migrant Swallows & Insect Feeding Paper Postcode Lottery Grant Cuckoos & Nightingales Bats Fund Youth Engagement Wader Project Officer Insect Decline Eddowes PhD Thetford Engagement Fund Kestrels Gillian Wills Trust Derek Coleman Fund David Hodgson Fund Raptor Monitoring Appeal Youth 25 Ringers’ Bursary Fund Small Specific Donations	Balance at 1 Apr 2024 £’000 108 14 36 30 11 8 20 72 32 1 14 13 15 54 - 20 34 49 250 - 33 2 3 11 24 2 27 18 - 29 28 29 51 121 - - 5 48 1,212	Income £’000 3 - 2 2 3 - - 8 76 - - - 3 19 19 - - 29 5 91 - - - - 7 20 1 11 15 29 3 36 10 - 104 35 - 11 528	Expenditure £’000 - (9) (8) (13) (19) - (16) (5) (91) - (3) (13) (6) (32) (39) (3) - (48) (47) - - - - (1) (2) (122) - - (1) (37) (22) (36) (21) - (18) (14) (3) (8) (623)	Transfers £’000 1 - - - 5 - - - 3 - - - - - 20 - - - - - - - - - - 100 3 - - (12) - - - (30) 5 - - (6) 89	Balance at 31 Mar 2025 £’000 112 5 30 19 - 8 4 75 20 1 11 - 12 41 - 17 34 30 208 91 33 2 3 10 29 - 31 29 14 9 9 29 40 91 91 21 2 45
					1,206

66 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements – Continued For the Year Ended 31 March 2025

16. RESTRICTED FUNDS (Continued)

The purposes of the funds are as follows: The Atlas Beyond the Maps Appeal continues to support research into Atlas data. The Northern Ireland Fund has been set up to support the BTO in Northern Ireland. The Dilys Breese Fund is for projects relating to nesting birds.

The Boddy & Sparrow Fund is for awards to the best amateur contribution(s) to either or both of the Bird Study and Ringing & Migration publications.

The Migration Fund is for research into migrating birds.

The Nightingale Appeal is to fund work on Nightingales and woodland birds. £5k was transferred from Birds in Trust to support this work.

The Swallow Appeal is to fund work on Swallows and migration. The Young Scientists’ Fund is to support the career development of young scientists. The Garden Research Fund is to support young scientists work on garden birds. The Out of Africa Fund is to fund work on African migrants. £3K was transferred from Birds in Trust to support this work. The Thrush Fund is to fund work on Thrushes.

The Curlew Appeal is to fund projects on Curlews. The Arctic Skua Fund is to support Arctic Skua work. The BTO Wales Fund is to support the BTO in Wales. The Sound Approach Fund is to support a number of specific projects.

The Tasso Leventis Fund is to support a number of specific projects. £20k was transferred from Birds in Trust to support these projects.

The Spotted Flycatcher Appeal is to support work on Spotted Flycatchers. The Chaffinch Appeal is to fund work on Chaffinches. The Seabird Appeal raises funds for work on seabirds. The Urban Appeal is to support studies of birds in towns and cities. The BBS Appeal is to fund work for Breeding Bird Surveys. The Rhodes Training Fund is to support survey training courses. The Migrant Swallows & Insect Feeding Paper donation is to fund a paper on Swallows. The Postcode Lottery Grant is for the Nunnery Lakes Reserve. The Cuckoos & Nightingales Fund is for research on Cuckoos and Nightingales.

The Bats Fund was set up from specific donations to support work on Bats and the development of the BTO acoustic work. The Youth Engagement Fund has been set up to support our work with young people. £27.5K was allocated from the David Hodgson Fund to support Youth Staff and Projects. £2.6K was transferred from Birds in Trust as per expression of wish of a legator. £68K was transferred from General funds to support Youth work.

The Short Eared Owl Fund is for work on Short Eared Owls in Scotland.

The Wader Project Officer Appeal Fund is for work on waders. £2.6K was transferred from Birds in Trust as per expression of wish of a legator.

The Insect Decline Fund is to support work on the decline in insects.

The Eddowes PhD fund was established to support a specific PhD project.

The Thetford Engagement Fund is for working with local communities to enhance BTOs engagement with them. £12k was transferred to General funds for consultancy costs to support this work.

The Kestrels Fund is to support work on Kestrels.

The Gillian Wills Trust is to support the recruitment and employment of a Development and Engagement Coordinator. The Derek Coleman Fund is to support Upland Monitoring.

The David Hodgson Fund provides support for our Youth Engagement Officer, Youth Birdcamp and Youth Engagement projects. £27.5k was transferred to Youth Engagement in accordance with the donor’s wishes.

The Raptor Monitoring Appeal is for work on birds of prey. £5K was transferred in from the Small Specific Donations fund in accordance with donor’s wishes.

The Youth 25 Fund supports Youth Engagement.

The Ringers’ Bursary Fund is to support ringing.

Small Specific Donations are small individual donations for specific purposes. £5K was transferred to the Raptor Monitoring Appeal as requested by donor.

Trustees’ Annual Report & Financial Statements 2024/25 | 67

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements – Continued For the Year Ended 31 March 2025

16. RESTRICTED FUNDS (Continued)

As at 31 March 2024

Atlas Beyond Maps Appeal Northern Ireland Fund Dilys Breese Fund Boddy & Sparrow Fund Migration Fund Nightingale Appeal Swallow Appeal Young Scientists’ Fund Garden Research Fund Out of Africa Fund Thrush Fund Farmland Bird Appeal Curlew Appeal Arctic Skua Fund BTO Wales Fund Bird Track Sound Approach Fund Tasso Leventis Fund Spotted Flycatcher Appeal Chaffinch Seabird Appeal Urban Appeal Rhodes Training Fund Migrant Swallows & Insect Feeding Paper Postcode Lottery Grant Cuckoos & Nightingales Bats Fund Youth Engagement Short Eared Owl Wader Project Officer Insect Decline Eddowes PhD Thetford Engagement Fund Kestrels Gillian Wills Trust Derek Coleman Fund David Hodgson Fund Ringers’ Bursary Fund Small Specific Donations	Balance at 1 Apr 2023 £’000 12 17 36 2 47 22 8 19 77 85 1 - 13 1 20 - 60 25 20 40 81 20 33 2 3 19 5 6 13 28 10 - - - - - - 1 51 777	Income £’000 4 49 3 - 17 3 - 11 8 64 - - 6 35 1 1 1 20 - - 15 7 - - - - 28 65 2 4 10 27 29 14 36 51 127 5 36 679	Expenditure £’000 - (52) (11) - (34) (14) - (10) (13) (84) - (2) (5) (23) (6) (1) (35) (62) - (6) (47) (27) - - - (8) (11) (196) (27) (5) (2) (27) - (5) (7) - - (1) (6) (727)	Transfers £’000 92 - 8 (2) - - - - - (33) - 2 - - - - 28 17 - - - 250 - - - - 2 127 12 - - - 19 - - (6) - (33) 483	Balance at 31 Mar 2024 £’000 108 14 36 - 30 11 8 20 72 32 1 - 14 13 15 - 54 - 20 34 49 250 33 2 3 11 24 2 - 27 18 - 29 28 29 51 121 5 48
					1,212

68 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements – Continued For the Year Ended 31 March 2025

17. UNRESTRICTED FUNDS

The Group and the Charity

The funds of the group and the charity include unrestricted funds comprising the following balances. The opening and closing fund balances for the group and the charity are identical.

As of 31 March 2025

General funds: Birds in Trust fund General fund Designated funds: Welch fund Unrestricted funds excluding Pension reserve Pension reserve	Balance at 1 Apr 2024 As restated £’000 4,184 1,355 5,539 501 6,040 (587) 5,453	Income £’000 874 7,303 8,177 7 8,184 - 8,184	Expend- iture £’000 (259) (8,026) (8,285) (97) (8,382) (23) (8,405)	Other Gains/ (Losses) £’000 4 5 9 - 9 180 189	Fund transfers £’000 (626) 287 (339) - (339) 250 (89)	Balance at 31 Mar 2025 £’000 4,177 924
						5,101 411
						5,512 (180)
						5,332

The Birds in Trust fund is intended primarily to provide long-term funding for BTO projects. Income from legacies is credited to this fund unless the wills provide otherwise. £593k was released to the General fund in support of JNCC Partnership projects. Other transfers totalling £34k were made in support of projects in the Youth Engagement, Tasso Leventis, Wader Projects, Out of Africa and Nightingales funds.

In the General fund, £12k was received from Thetford Engagement to fund consultancy costs.

£68k was released in support of Youth Engagement. £593k was received from Birds in Trust in support of JNCC Partnership projects. £250k was transferred to the Pension Reserve fund in respect of the pension deficit repair contribution. The Welch fund is for migration research.

The Pension Reserve fund reflects the defined benefit pension scheme deficit. £250k was transferred from the General fund in respect of the pension deficit repair contribution. Other pension reserve movements are disclosed in Note 23.

As of 31 March 2024 As restated

General funds: Birds in Trust fund General fund Designated funds: Welch fund Unrestricted funds excluding Pension reserve Pension reserve	Balance at 1 Apr 2023 £’000 3,129 1,441 4,570 547 5,117 (1,110) 4,007	Income £’000 2,080 6,697 8,777 8 8,785 - 8,785	Expend- iture £’000 (290) (6,927) (7,217) (54) (7,271) (50) (7,321)	Other Gains/ (Losses) £’000 32 40 72 - 72 393 465	Fund transfers £’000 (767) 104 (663) - (663) 180 (483)	Balance at 31 Mar 2024 £’000 4,184 1,355
						5,539 501
						6,040 (587)
						5,453

Trustees’ Annual Report & Financial Statements 2024/25 | 69

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

18. ANALYSIS OF FUNDS ACROSS NET ASSETS

The Group and Charity As of 31 March 2025

Unrestricted Funds General funds: Birds in Trust fund General fund Designated funds: Welch fund Unrestricted funds excluding Pension reserve Pension reserve Restricted Funds Total As at 31 March 2024 As restated Unrestricted Funds General funds: Birds in Trust fund General fund Designated funds: Welch fund Unrestricted funds excluding Pension reserve Pension reserve Restricted Funds Total	Fixed Assets £’000 - 2,431 2,431 - 2,431 - 2,431 - 2,431 Fixed Assets £’000 - 2,427 2,427 - 2,427 - 2,427 - 2,427	Investments £’000 236 293 529 - 529 - 529 - 529 Investments £’000 232 287 519 - 519 - 519 - 519	Current Assets less Total Liabilities £’000 3,941 (1,620) 2,321 411 2,732 (180) 2,552 1,206 3,758 Current Assets less Total Liabilities £’000 3,952 (772) 3,180 501 3,681 (587) 3,132 1,212 4,306	Defined Benefit Pension Liability £’000 - (180) (180) - (180) - (180) - (180) Defined Benefit Pension Liability £’000 - (587) (587) - (587) - (587) - (587)		Total Net Assets £’000 4,177 924 5,063 411 5,512 (180) 5,332 1,206 6,538 Total Net Assets £’000 4,184 1,355
						5,539 501
						6,040 (587)
						5,453 1,212
						6,665

70 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements – Continued For the Year Ended 31 March 2025

19. OPERATING LEASE COMMITMENTS At the year end the group had outstanding lease commitments for future minimum lease payments under non-cancellable leases, as follows: Due within one year Due within two to five years	2025 £’000 64 118 182	2024 £’000 47 110
		157

20. RECONCILIATION OF NET INCOME/(EXPENDITURE) TO NET CASHFLOW FROM OPERATING ACTIVITIES

Net income per Statement of Financial Activities Adjustments for: Items representing cash movements (Increase)/decrease in stocks (Increase)/decrease in debtors Increase/(decrease) in creditors Investment income Items not representing cash movements Depreciation (Gains)/losses on investments Expenditure on defined benefit pension plan liability Cash movements not appearing in the Statement of Financial Activities Pension deficit repair contribution Net cash inflow/(outflow) from operating activities	Group 2025 £’000 (307) (4) 1,188 200 (104) 19 (9) 23 1,005 (250) 755	Group 2024 As restated £’000 1,498 23 (590) (130) (92) 18 (72) 50 694 (180) 514	Charity 2025 £’000 (307) - 1,202 175 (104) 19 (9) 23 999 (250) 749	Charity 2024 As restated £’000 1,498 - (612) (108) (92) 18 (72) 50
				671 (180)
				491

Trustees’ Annual Report & Financial Statements 2024/25 | 71

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements – Continued For the Year Ended 31 March 2025

21. FINANCIAL INSTRUMENTS

The carrying amounts of the groups and the charity’s financial instruments are as follows:

Financial assets Measured at fair value through net income/expenditure: Fixed asset listed investments (Note 10) Equity instruments measured at cost less impairments: Fixed asset unlisted investments (Note 10)	Group 2025 £’000 529	Group 2024 £’000 519	Charity 2025 £’000 Charity 2024 £’000 529 519 - -

22. CONTINGENT ASSET

The Trust has been notified of a legacy involving a property, which has not been recognised in the financial statements as at 31 March 2025, as the income recognition criteria under the Charities SORP (FRS 102) have not yet been met.

Specifically, the Trust has been named as a beneficiary in the will of a deceased individual, with an entitlement to a residential property. At the year end, entitlement was not confirmed, the estate was still in the process of administration, legal title had not yet transferred to the charity and the timing and amount of any potential benefit remained uncertain. The property is expected to achieve a value of around £850k in an open market sale.

The legacy will be recognised when entitlement is confirmed, receipt is probable, and a reliable measurement of value can be made.

72 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

23. PENSIONS

The Group and the Charity

Defined contribution pension plan

The Trust operates a Group Self-invested Personal Pension Scheme run by Aegon. Staff contribute to this defined contribution scheme at a minimum rate of 4% of salary, and the BTO contributes at a flat rate of 11%. The Trust made contributions of £560k during the year (2024: £480k).

Defined benefit pension scheme

The Trust’s defined benefit pension scheme, a ‘final salary’ scheme, is closed. The last triennial actuarial valuation of the scheme was carried out as at 31 March 2024. At that date the assets were valued at £11,102k and the liabilities at £12,715k, giving a net deficit of £1,613k and a funding level of 87%. A deficit recovery plan was subsequently agreed between the Board and the pension fund trustees, by which the shortfall would be made good by annual lump sum deficit repair payments spread over the years to 2031.

For the purposes of the group financial statements a separate valuation is carried out at the balance sheet date by a qualified independent actuary in accordance with Financial Reporting Standard 102 (FRS 102). The amounts recognised in the statements of financial activities for the year and the balance sheets were as follows:

Recognised in the statements of financial activities: Expenditure: Interest income Interest cost on liabilities Net interest on net defined benefit liability Other recognised gains/(losses): Actual return on scheme assets (excluding interest income) Actuarial gain/(loss) on liabilities Recognised in the balance sheets: Fair value of scheme assets Present value of defined benefit obligations Defined benefit pension scheme liability at 31 March Reconciliation of funded status: (Deficit) at 1 April Employer pension deficit repair payment Net interest on net defined benefit liability Remeasurement gain (Deficit) at 31 March	2025 £’000 546 (569) (23) (953) 1,133 180 2025 £’000 10,557 (10,737) (180) 2025 £’000 (587) 250 (23) 180 (180)	2024 £’000 517 (567)
		(50)
		149 244
		393
		2024 £’000 11,103 (11,690)
		(587)
		2024 £’000 (1,110) 180 (50) 393 (587)

Trustees’ Annual Report & Financial Statements 2024/25 | 73

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

23. PENSIONS (Continued)

Changes in the fair value of the pension scheme assets were as follows:

Changes in the defined benefit obligations were as follows: Present value of defined benefit obligations at 1 April Interest cost on liabilities Benefits paid Actuarial gain/(loss) Present value of defined benefit obligations at 31 March The amount of each major class of pension scheme assets within the total fair value of the scheme assets was as follows: Equities Bonds Annuities Cash The total return on scheme assets was as follows: Interest income Actual return on scheme assets (excluding interest income) Total return on scheme assets The principal actuarial assumptions used were as follows: Discount rate Inflation assumption (RPI) Inflation assumption (CPI) Rate of increase for non-GMP pensions in deferment Rate of increase for pensions in payment (RPI, min 3% max 5%) Expected future lifetime from age 65: Male – currently aged 65 Female – currently aged 65 Male – currently aged 45 Female – currently aged 45 Fair value of scheme assets at 1 April Interest income Actual return on scheme assets (excluding interest income) Employer pension deficit repair payment Benefits paid to members Fair value of scheme assets at 31 March	2025 £’000 (11,690) (569) 389 1,133 (10,737) 2025 £’000 3,298 6,689 115 455 10,557 2025 £’000 546 (953) (407) 2025 5.90% 3.25% 2.75% 2.75% 3.65% 2025 No of years 21.5 23.6 23.1 24.8 2025 £’000 11,103 546 (953) 250 (389) 10,557	2024 £’000 10,672 517 149 180 (415) 11,103
		2024 £’000 (11,782) (567) 415 244
		(11,690)
		2024 £’000 6,012 4,379 135 577 11,103 2024 £’000 517 149 666 2024 4.95% 3.25% 2.70% 2.70% 3.65% 2024 No of years 21.6 23.8 23.2 24.9

74 | Trustees’ Annual Report & Financial Statements 2024/25

FINANCIAL STATEMENTS

The British Trust for Ornithology Notes to the Consolidated Financial Statements - Continued For the Year Ended 31 March 2025

24. Prior period adjustment

Overstatement of stock

A prior period adjustment has been recognised to correct historic overstatement of stock valuations.

The Group Period ended 31 March 2024 Changes to the balance sheet Current assets Stocks Reserves Unrestricted reserves b/fwd Unrestricted reserves c/fwd Changes to the Statement of Financial Activities Ringing and tagging costs Net income/(expenditure) The Charity Period ended 31 March 2024 Changes to the balance sheet Current assets Amounts due from Group undertakings Reserves Unrestricted reserves b/fwd Unrestricted reserves c/fwd Changes to the Statement of Financial Activities Corporate & trust donations & grants Net income/(expenditure)	As previously reported £’000 282 5,145 6,078 463 1,498 As previously reported £’000 560 5,145 6,078 648 1,498	Adjustment As restated £’000 £’000 (38) 244 (27) 5,117 (38) 6,040 11 474 (11) 1,487 Adjustment As restated £’000 £’000 (38) 522 (27) 5,117 (38) 6,040 (11) 637 (11) 1,487

Trustees’ Annual Report & Financial Statements 2024/25 | 75

Birds Science People

Birds Science People

British Trust for Ornithology The Nunnery, Thetford, Norfolk IP24 2PU Tel: [phone] Web: www.bto.org Email: [e-mail] Bluesky: btobirds.bsky.social Registered Charity Number 216652 (England & Wales), SC039193 (Scotland)

COVER IMAGE: BLACK-HEADED GULL, DAVID TIPLING / BIRDPHOTO.CO.UK