BTO publishes various reports, from those covering the annual results of core surveys, through scientific studies, and on to those produced in partnership with other organisations. Many of these are published as BTO Research Reports. You can access all of our reports from here, though note that we are currently updating the reports section, working backwards through time to bring all of the report pages into a consistent format. You can read our Annual Report and Accounts in the Governance section.
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Waterbirds in the UK 2023/24
The report provides a single, comprehensive source of information on the current status and distribution of waterbirds in the UK for those interested in the conservation of the populations of these species and the wetland sites they use.Key stories from this report include more updates on avian influenza affecting migratory Barnacle Goose and Mute Swan, as well as a focus on the latest WeBS Alerts, looking at how wintering waterbirds are doing in protected areas.View the press release for this report
22.05.25
Reports
The Breeding Bird Survey 2024
These are the main schemes for monitoring the population changes of the UK’s widespread breeding birds, providing an important indicator of the health of the countryside.The results are published annually as Official Statistics and used widely by Defra and the Statutory Nature Conservation Bodies (SNCBs, e.g. Natural England and NatureScot) to set priorities and to inform conservation action, and as the evidence base against which the UK’s biodiversity targets are measured.BBS data are also routinely used in research, with recent examples including peer-reviewed papers published in 2022 and 2024 which measured the efficacy of the UK’s network of protected areas in supporting wildlife.The 2024 Breeding Bird Survey Report highlights the continuing decline of some farmland species and more recent declines of woodland birds, at least in England. In Scotland, there is a focus on upland birds, where an all-species indicator using BBS data shows a 20% decline since 1994. In Wales, there are mixed fortunes, with species like House Sparrow bucking the downward trend seen in England, whilst Curlew are in severe decline, as they are elsewhere in the UK. Some songbirds in Northern Ireland, such as Blackbird are doing comparatively well compared to the wider UK trend.We thank nearly 3,000 skilled and dedicated volunteers who give their time to BBS and WBBS and make the monitoring of the UK’s breeding birds possible.Download the 2024 reportOr, browse all editions of the Breeding Bird Survey Report >
15.05.25
Reports
Scientific support to the trial of Spoor AI at the European Offshore Wind Deployment Centre
This report assesses the capability of a Spoor AI camera system with both mono-vision (single-camera) and stereo-vision capabilities for bird monitoring deployed at the European Offshore Wind Deployment Centre in Aberdeen Bay using both theoretical considerations and onshore and offshore field trials.
25.04.25
Reports
A review of existing methods to collect data on seabird flight height distributions and their use in offshore wind farm impact assessments
This document presents a review of existing methods for collecting seabird flight height data and their potential to produce flight height distributions that might be used in CRMs. The strengths, weaknesses, and limitations of different methods are identified and sources of measurement and sampling error, uncertainty and bias assessed. Best practice recommendations are provided for prominent methods and how data might be best utilised to inform stakeholders is considered.
15.04.25
Reports
Northern Ireland Seabird Report 2024
This report includes detailed information about the population trends and breeding success of seabirds in Northern Ireland, over the 2024 breeding season. Monitoring reports for Strangford Lough and the Outer Ards are included, as well as several additional contributor articles.
27.03.25
Reports
Assessment of recent Hen Harrier population trends in England through population modelling
This study uses a population modelling approach to explore the effects of changes in rates of productivity, survival, and settlement on population growth in the English population of Hen Harriers.
14.03.25
Reports
Bat distribution and activity in the Skell Valley catchment, 2024 Report
This report presents the main findings from survey work delivered using passive acoustic monitoring devices deployed across the Skell Valley catchment. Through the surveys that we support we aim to improve knowledge and understanding of species distribution and activity, covering a range of taxonomic groups, including birds, bats, small terrestrial mammals and insects. Through the approach we provide robust datasets that can be used to inform better decision-making processes.
07.03.25
Reports
Farming in Project Landscapes – Turtle Dove Monitoring Project, 2024 Report
This report presents the results of work using static acoustic recorders, deployed between May and mid-August 2024, to provide extensive acoustic data for the Stour Valley Farmer Cluster.
04.03.25
Reports
Ryevitalise – Bats and Ancient Trees, 2020–2024 Report
Working with a network of volunteers, static acoustic bat detectors were deployed over five survey seasons, 2020-2024, to provide bat data for the Ryevitalise Landscape Partnership Scheme area of the North York Moors National Park. This report provides an overview of the survey coverage and results from the project.
04.03.25
Reports