Breeding Bird Survey

Chiffchaff by Paul Newton

BBS monitors the population changes of 117 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 117 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.
Project Lead
Email Contact
bbs@bto.org
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Project timeline, contributions & findings

Project timeline

  • February – March Forms sent or downloaded
  • March Reconnaissance visit
  • Early April – mid May Early visit
  • Mid May – late June Late visit
  • May – August Wider Countryside Butterfly Survey
  • End of August Data entry deadline


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