OSLO BIRDER: 1st winter male Pine Grosbeak

Wednesday 15 December 2021

1st winter male Pine Grosbeak

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 1^st 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 1^st winter with 1^st 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 1^st winter, and this winter probably 90% of birds are first winter, then you can try to sex it. Some (most?) 1^st winter males have some red feathers coming through on the head but apparently not all so it might well be that only some 1^st 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 1^st 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 2^nd winter male looks like. As 2^nd 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 2^nd winter male even though I interpret the shape of the tail feathers as being 1^st 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.