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Tuesday, 3 August 2010

......And further comments on ageing

Greetings All

Indeed, it is true that many finches do not attain adult male plumage until after their first year... the most important point being that female Red Crossbills are yellow, and female House Finches are not.

Male Purple Finches in their first year are streaked, like females, not pallid red, pink, or yellow. I do not know much of House Finch biology, but it is my suspicion that first year HOUSE FINCHES that do not attain adult male like plumage, look rather like females instead of yellow or pale males (a glance at Peter Pyle's tome would likely tell, but I am not at home). One could argue that a first year bird might not be as successful at obtaining food, and thus more likely to be yellow, but then we are starting to stretch a bit.

The data on Fire Island, New York, are quite interesting (as are the data from Veit's study), but on the other hand, it should not surprise us; nearly all finch species have a tendency to wander widely, including other Carpodacus finches.

The thing that bothers me most about the UK bird is that it is in a plumage that is much more common in captivity than in the wild. If the bird had arrived in the common plumage (of either a first year male, or an adult), a ship-assisted bird would not seem so unlikely (Steve Mlodinow)