03 December 2010

Whats going on with wintering Blackcaps?

Very few Blackcaps used to stay/survive in this country during the winter but instead go south to Iberia or northern Africa. These days it is still very nice to see one in winter but it wouldn't warrant organising a big twitch.

Are Blackcaps staying for the winter or is something else happening?

Ringing recoveries have shown that our Blackcaps in summer are replaced with birds from continental Europe when winter arrives (e.g. 159 ringed from Belgium and 50 from The Netherlands so far). These birds are now able to survive better, possibly due to warmer winters and/or an increase in garden bird feeding.

Saying that, we have just heard from John Walshe, where he had ringed a breeding female Blackcap on 17 May 2010 and he has just caught it again at the same site in mid Suffolk. Obviously this bird hasn't gone south as expected, so is this a new strategy to get back to the breeding grounds quicker or is this just a rare occurrence? More ringing for winter Blackcaps is needed I think.

Thanks to John Walshe for letting us know and Dawn Balmer for the photo.

1 comment:

  1. There are two things probably going on; an increase in 'residency' (birds spending the winter in their breeding area) and an influx of migrants from further east. Martin Schaefer, a researcher at Freiburg University in Germany has been studying this. See this paper for example: http://www.biologie.uni-freiburg.de/data/bio1/schaefer/pdf/rolshausen10.pdf