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Honey Buzzard moult question (1 Viewer)

Biancone

to err is human
Some of the Honey Buzzards I've been seeing lately (northern Appennines, Italy) have looked in many ways like the usual field guide illustrations, but in some cases (I think at least three individuals) the underwing shows a dark section in the angle of 'hand' and 'arm'. It's hard to define the area while the bird is in flight, but I think it corresponds to the first few secondaries. These also look noticeably shorter than the rest of the secondaries, which give the wing a bulging appearance. A couple of birds have shown a second dark/short section in the secondaries nearer the body.
I don't have any reference source for moult pattern at hand, but I wonder if these are likely to be some remaining first-plumage feathers? And does this suggest anything about possible age of the birds?
Something I'd not noticed until recently is that strong backlighting seems to have an effect on what the observer sees in HB wings (never noticed similar in CBs), increasing their 'patchiness', so that the pale areas look almost transparent while the feathers with more pigment (the ones I'm thinking may be juvenile) look even more dark. I've got one very poor photo taken with a pocket 'travel' camera, but I'll avoid embarrassment because I've got no card reader with me.
Any thoughts welcome.
 
Thanks for responses! Couple of very nice Honey images there. The ventral shot has some similarity to what I tried to describe, certainly there's something going on with different feather ages in the hand/arm angle. In fact the pic linked below, in the ID section shows what I was seeing more closely. With my feeble non-broadband 'dongle' it would take me all evening to open the pdf. In fact I have this book marked on my home PC, so that's something to check out when I'm forced to go home again!
http://www.birdforum.net/attachment.php?attachmentid=280093&d=1282805738
 
Breeding Honey Buzzards undergo a partial moult of secondaries \ primaries during the summer. Females seem to have a more heavy mount during the incubation period. Male moult is usually lighter. Both can account for the feature you are describing. I see very little of flying young , but have not noticed any moult. Honey buzzard juveniles can look very different to adults , the wing position seems not quite right compared to adult and the plumage is distinctive on many birds , but they are very variable.
 
Thanks for your input Tideliner. Most of the birds I've been seeing in August have been very 'gappy'. At least a couple have had a feather or two missing from the inner secondaries, and least one had another gap in the outer secondaries. A couple have had one or two central tail feathers missing. Not certain I've seen juveniles but suspect two I saw (only in dorsal view, flying in close order along a valley below me) may have been: very neat and tidy, identical mid-brown above, with a pale rump crescent, a pale basal primary patch and darker at the tips. Unfortunately I wasn't here at the right time to work out which were breeding pairs. Hope they were successful in Norfolk this year - in your last post I saw you were worried birds hadn't turned up.
 
We finaly got a pair of honey buzzards in the 3rd week of June. To late to breed , but during the summer 5 different birds apeared at various times.
 
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