The BBS was launched in 1994, and involves thousands of volunteer birdwatchers carrying out standardised annual bird counts on randomly-located 1-km sites.
Comparing these annual counts enables us to monitor the population changes of over 100 bird species. Read about the methodology and survey design.
The survey is designed to be a simple and enjoyable birdwatching exercise. Read more about how to take part.
The BBS replaced the previous BTO population monitoring survey, the Common Birds Census (CBC). Trends from the two schemes can be combined to give long-term bird population trends that run from the 1960s to the present. The latest joint CBC/BBS trends are published in the BirdTrends Report.
For more information about how the trends are generated, and research carried out using BBS data, see our research & conservation section.
The BBS is run by the British Trust for Ornithology (BTO), and jointly funded by the BTO, the Joint Nature Conservation Committee (JNCC, the statutory adviser to Government on UK and international nature conservation, on behalf of Natural Resources Wales, the Department of Agriculture, Environment and Rural Affairs, Northern Ireland, Natural England and Scottish Natural Heritage) and the Royal Society for the Protection of Birds (RSPB).
The BBS Team
Sarah Harris is the BBS National Organiser at the BTO, responsible for the day-to-day running of the BBS, liaising with BTO Regional Organisers and volunteers, promoting the scheme, maintaining the database, and producing the annual report.
David Noble is the Principal Ecologist for Monitoring at the BTO, responsible for strategic developments in biodiversity monitoring. Dawn Balmer is the Head of the Surveys Team, which includes the BBS and a number of other surveys. Andy Musgrove is an Associate Director overseeing the Monitoring Teams (Surveys and Demography). Stephen Baillie is a Senior Research Fellow at the BTO, and has overseen the BBS since its inception in 1994.