Last gaps to fill


Fieldwork for Bird Atlas 2007-11 draws to a close at the end of this breeding season and between now and then, volunteers across Britain and Ireland are racing to fill the last few gaps.

There are two areas where we need help. Firstly, to look for breeding evidence that will confirm a species has bred in a 10-km square. The 10-km squares that need most help are shown on the map below, but most squares in Britain and Ireland still have some fairly easy gaps to fill. Species like Cuckoo, Swift, Spotted Flycatcher, Dunnock, Collared Dove and Woodpigeon tend to be poorly recorded. There are some species that are notoriously difficult to confirm breeding such as Grasshopper Warbler and Water Rail and in many squares these will remain at ‘probable’ breeding based on the evidence we have collected. At this time of year we are looking for adults carrying food for young or faecal sacs away from the nest (code FF), occupied nests (code ON) or recently fledged young still showing some dependency on adults (code FL). If you are lucky enough to be birding in breeding wader habitats, then codes such as DD for distraction display are useful.

Gaps in confirmed breeding in Britain and Ireland.

Some of the photos posted on Iris have led us to confirm breeding in a 10-km square or tetrad (2x2km square) so thank you very much to those photographers who have responded to our requests for information on location. Being able to allocate a tetrad letter to a record will help the local atlases with their tetrad based county atlas. There are over 40 local atlas projects underway in Britain and Ireland.

Secondly, we need help from birders to add new species to a 10-km square. Using species lists from the 1988-91 Breeding Atlas we have a target ‘expected species list’ for every 10-km square, and although there will have been gains and losses since that Atlas, the list does provide a useful guide to how well the square has been surveyed. Having said that, there are some squares like TG50 covering Great Yarmouth and Breydon Water, which despite a lot of effort, is still showing as a square that needs more help. Do you know of any breeding Spotted Flycatchers in TG50? The map below shows the 10-km square which may still have species to find. If you login to www.birdatlas.net (you will need to register first) you can access the ‘Priority Squares’ feature which will list species that have been recorded nearby but not in the target square.


Gaps in expected breeding species.

By the end of July, volunteers will have completed their late breeding Timed Tetrad Visits and that part of the project will be complete. We can continue roving in search of new species and breeding evidence until the end of the breeding season.

Thank you to everyone who has contributed records to the Bird Atlas so far and made it such a success. If you would like to be sent a list of breeding evidence gaps for where you live please email dawn.balmer@bto.org and supply your postcode.

Click here to access an interactive version of the roving gaps where you can click and identify the 10-km square.

Click here to access an interactive version of the confirmed breeding gaps where you can click and identify the 10-km square.

Written by: Dawn Balmer