Breeding Bird Survey

Chiffchaff by Paul Newton

BBS monitors the population changes of 118 breeding bird species across the UK thanks to the dedication of almost 3,000 volunteers who survey their randomly selected 1-km square each spring.

The BTO/JNCC/RSPB Breeding Bird Survey (BBS) is the main scheme for monitoring the population changes of the UK’s common and widespread breeding birds, producing population trends for 118 bird and nine mammal species. 

The survey involves a recce visit and two early-morning spring visits to an allocated 1-km square, to count all the birds you see or hear while walking two 1-km lines across the square and record any nest counts for colonial nesting birds in the square.

You can optionally record mammals and visit your square later in the season to survey for butterflies. There is the option to return data on paper, via field recording forms or to submit your data on BBS-Online.

Time / skill required

  • Undertake three site visits between April and June - a recce and two morning visits, along with data entry.
  • Able to identify UK breeding birds by sight, song and call.
  • If you have the necessary bird ID skills to take part in the Breeding Bird Survey but want to learn more about survey methods, there are a number of BTO training courses covering this subject.
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Read the latest BBS report

The Breeding Bird Survey started in 1994, and a report is produced every year containing population changes and other results from the scheme.

The 2023 Breeding Bird Survey Report celebrates the 30-year anniversary of fieldwork for the scheme, in particular the amazing commitment and dedication of its volunteers.

It is a mixed picture for birds: Swift and Swallow show widespread decline, whereas some species are faring better, particularly in Scotland where species of scrub and woodland are doing better than in England.

Read the 2023 Breeding Bird Survey report

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