29 November 2010

Redpoll... but which one?

Winter is a good time for ringers to be catching Redpoll, as you an tell from the previous post.

The plumage and biometrics of Redpoll are looked at very closely by ringers which need to separate them into the current 3 species, Lesser (the most commonly caught Redpoll), Common Redpoll and Arctic Redpoll. Sorby Breck Ringing Group were out ringing and they came across something very interesting.

This is actually a Lesser Redpoll that had already been ringed by the group. Interestingly when it was ringed it looked like any other Lesser Redpoll and lacked all this white. This condition is likely to be Vitiligo, which means this bird could get whiter with every moult but start out looking like a normal brown Redpoll. This condition is most commonly seen in Blackbirds and Jackdaws but has also been recorded in Redpoll.

The graph below shows the number of Redpoll ringed in 2009 by month.

Many thanks to Geoff Mawson (for the photo as well), David Williams and John Wint for letting us know.

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