Determining age and sex of Pine Grosbeaks in the winter is not always easy unless of course they are adult males whose red plumage is not to be mistaken. The problem arises in separating adult females from 1st winter birds of either sex. The shape of the tail feathers is supposed to be the best way to see if it is an adult or 1st winter with 1st winter birds having much more pointy feathers but I must admit to not always finding this very straightforward. If you have managed to age it as a 1st winter, and this winter probably 90% of birds are first winter, then you can try to sex it. Some (most?) 1st winter males have some red feathers coming through on the head but apparently not all so it might well be that only some 1st winter males can be safely sexed and the rest just ended up as unsexed. Females can also have very orangey heads so there is also the risk of confusing dark orange and red..
Usually when identifying a bird as a 1st winter
male there are only a handful of red feathers but earlier this week I came across
a most striking bird that had come a long way in moulting to adult plumage including
red feathers on the uppertail coverts. I do not remember seeing such a bird
before and wish the light had been better to have allowed some better quality
pictures to document this bird. I find the literature quite unclear about what
the plumage of a 2nd winter male looks like. As 2nd
winter male is not mentioned in any of my literature I assume that it is the
same as adult male but there is a possibility that this bird is a 2nd
winter male even though I interpret the shape of the tail feathers as being 1st
winter. Moult limits are also mentioned a lot especially in a “Handbook of Western
Palearctic Birds” by Shirihai & Svensson although I must admit to not being
able to see the features that the picture captions say should be visible….
I am regularly visiting two locations with Grosbeaks in Oslo and the number of birds I find varies from day to day but there seems to be a clear reduction in the birds despite there still being LOTS of berries.
Pine Grosbeak (konglebit) - a very colourful 1st winter male I believe |
very pointy tail feathers would seem to be juvenile and therefor proof it is a 1st winter |
the red tips to the lower uppertail coverts are visible here and also in the video |
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