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|Wednesday 16th January 2008, 16:44||#1|
Join Date: Apr 2007
are these ylgulls
or are they just herrings.If just Herrings what are the main ylg id features to look for in the field.
|Wednesday 16th January 2008, 18:57||#2|
Join Date: Aug 2002
I presume that the first two are of the same bird? I think that they are all Herring Gulls anyway, the first two being 2nd-winters (or, most likely, the same 2nd-w), with the third being more like a 3rd-winter.
Identification of subadult Yellow-legged Gulls isn't without its problems, with some pretty difficult birds (that are either less than classic Yellow-leggeds or fiendish lookalikes that take time to sort out), so, if you've never seen one, I'd suggest putting most of your effort into looking for adults, at least at first, though by no means ignoring any subadults that strike you as odd either.
I must stress that it is vitally important that you familiarise yourself with the variation within the different ages of Herring, Lesser Black-backed and Great Black-backed Gulls (some 1st-w GBB can look like some 1st-w Yellow-leggeds), as it is only in doing this that you start to get a better 'feel' for anything that lies outside of these species. That said, a classic adult Yellow-legged can be quite distinctive: at this time of year, many are starting to get brighter yellow legs than during the depths of the winter, and a bird showing such leg colour, upperparts shade similar to that of your average Common Gull, a powerful bill, full chest, long 'rear' etc can stand out amongst Herrings or Lesser Black-backeds. The very white-headed look is good too, but beware that some adults of LBB and especially Herring are becoming quite white-headed too around now: nevertheless, a white-headed bird with a darker mantle shade is always worthy of further investigation.
Any age from 2nd-w onwards will have some adult-type mantle and scapular feathers at least, by and large, and this will help you to pick candidates out from amongst similarly-aged Herring or Lesser Black-backed. Note that precise mantle shade can be difficult to judge on a bird in isolation, due to light conditions etc (basically, gulls will look darker in poor light and paler in strong sunlight), so it is best to compare a bird with others around it.
I hope that this helps for now?
|Wednesday 16th January 2008, 22:10||#4|
Join Date: Mar 2005
Firstly Pete, it´s wise to put a date to the observation!
To put it straight without to much plumage discussion, my immediadte impression is Herring Gull purely on struckture! How to explain that in simple words, and at the same time make statements that gulls vary - sometimes in such a degree that it´s impossible to be certain of, lets say, a 2nd winter Herring or a 2nd winter Yellow-legged.
I will try to illustrate the structural difference between Herring and Yellow-legged (remember that, although often fairly distinctive difference, this is a simplifyed way to suggest the difference between the two).
Take 2nd winter type YLG:
2cy, both Sept.
Some YLG Nov:
Herring, 2nd winter (3cy).
Some 2nd winter type YLG:
to compare with Herrings:
Direct, in this case a straightforward comparison, with a YLG and a Herring to note stronger bill usually blunter-tipped, larger head with bulbous forehead and somehow flatish crown and bull-necked. Also note the body structure with a slender hindpart and usually with longer primary projection in YLG.
and this Herring to note the structure (but also plumage difference in this case to illustrate the often less advanced plumage of many Herrings at this age type:
Also very good images by this Swedish birder:
Harry has good points about the learning process and description.
Last edited by JANJ : Wednesday 16th January 2008 at 22:12.
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