Data

Information published on our website

Facts and Figures on British birds
Trends in numbers and breeding performance over 50 years
Which birds can be found near you

BTO survey information

Detailed Information on BTO Surveys

Search for data

Find out what Survey Data are available
Search for BTO survey information on a SPECIES
Search for BTO survey information about an AREA
Request data from the BTO

BTO data policies

The BTO's Data Policy
The BTO statement on Data Quality
Data on Sensitive Species - BTO statement

Too wet to nest?

A common issue that many analysts of biological data encounter is that of detectability. For a human population we can (in principle) count every individual. For wildlife though, things are trickier, and only rarely is...

Article

Avian influenza

From symptoms and outbreaks to impacts and mitigation, learn more about avian flu and our dedication to tackling it.

Tagged Lesser Black-backed Gull. Gary Clewley

Article

Bird tracking — a masterclass

Phil Atkinson explains the technology behind tracking.