Common Swift and House Martin breeding data

Common Swift and House Martin breeding data.

Populations of Common Swift Apus apus and House Martin Delichon urbicum are declining.  As a result, both species are Amber listed; Birds of Conservation Concern 4 (Eaton et al. 2015).  Both species breed on or in buildings, which may be subject to demolition or renovation, resulting in the loss of breeding sites; acknowledge as one of the probable causes of the population declines.  In order to mitigate this impact, we need to know where the birds are breeding.  Therefore, we are asking birders and members of the Bedfordshire Bird Club to submit records of known breeding sites.  To do this effective, the records will need to contain the following information:

  1. Species; record the number of birds seen, including records of low-level (roof-top height) screaming parties, as this is indicative of a nearby breeding colony; plus the number of nest sites (for Swifts this will be the number of entry points to a roof).


  1. It may be useful to record breeding activity using BTO codes where applicable; these have been revised specifically for Swifts:



  • P: pair in suitable nesting habitat.
  • T: permanent territory (defended over at least 1 week).
  • D: courtship and display (include low-level screaming parties of Swifts).
  • N: visiting probable nest site.
  • A: agitated behaviour.


  • FL: recently fledged young seen in flight; include low-level screaming parties of Swifts seen in July.
  • ON: adults entering or leaving nest site indicating occupied nest.
  • FF: adult carrying faecal sac or food for young.
  • NY: nest with young seen or heard.

A full address of the property; house number/name, street name, town; 1km grid square reference.


  1. Enter your records on to the RSPB website at: (


Eaton, M A., Aebisher, N J., Brown, A F., Hearn, R., Lock, L., Musgrove, A J, Noble D G., Stroud, D G., and Gregory, R D.  (2015). Birds of Conservation Concern 4: the population status of birds in the United Kingdom, Channel Islands and the Isle of Man.  British Birds 108: 708-746.

Bedfordshire Bird Club, Records & Research Committee:

Graham Goodall. Research Officer.

Roger Hicks. BTO Regional Representative.

Steve Blain. County Bird Recorder.