Sunday, February 06, 2011

Redpoll studies, 1st winter female Common Redpoll

I have been nurturing an ever increasing flock of Redpolls in the garden for the past two weeks after taking out a niger seed direct debit. After a little bit of vegetation management and a well placed 30ft net, birds were soon in the hand. So far 29 have been ringed and have proved as educational as ever. When in the hand, wing length of Redpolls provide a useful aid to identification and seperation of Lesser (cabaret) and Common (flammea) Redpolls.
(Common Redpoll - male 70-78mm, female 68-76) (Lesser Redpoll - male 68-73.5, female 67-71).
As a reference tool, I have taken several photographs of each bird I have caught, focussing on key aspects of their features which assist with identification. With so many Common Redpolls and an increasing number of Arctic Redpolls present in the UK during this recent influx it is also offers an opportunity to potentially catch some interesting individuals. The above bird has so far been the most definitive Common Redpoll caught. Firstly with very sharp pointed tail feathers it is clearly a 1st winter bird (adults have broad and rounded tail feathers), secondly it lacks any trace of red on its throat, breast or rump indicating it is female. Next comes the wing length, at 74mm it is 3mm greater than the range for a female Lesser Redpoll. Ok, so ignoring all that, it has pallid grey upperparts, strong white wingbars, a pale broad supercillia, a pale white streaked rump which bleads white in to the surrounding flanks and lower back - all features indicative of Common Redpoll.
What follows are pictures of other birds I have handled and a bit of discussion regarding their identification. Just remember Redpolls are in a very active evolutionary phase !

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