Thursday, October 21, 2010

Age and sex ID based on molt, part 2

First fall immature Ruby-crowned Kinglet, Central Park, NYC, October 8th

Click on the image to get a larger view of this bird (and ignore the fact that the © statement is floating in mid-air). This is a pretty classical example of retrix (tail) and primary (wing) feather shape in a first fall immature - the feathers are somewhat pointed and in fact in this bird the feathers come to a sharp point. Adults have blunt and rounded ends to their feathers. At this time of year, when both adults and immatures have relatively recently molted their flight feathers as well as their body feathers, all of the plumages look pretty fresh. If I ever get an adult Kinglet to pose for me - these are especially frenetic birds - I shall put one up for comparison.

I'm not sure there's any meaningful plumage difference between sexes at this stage, so I'm not even going to try.

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