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Yellow Legged Gull & Lesser Black Backed Gull (1 Viewer)
- Thread starter Andrew
- Start date
Ashley beolens
Breeding the next generation of birders.
I'm no expert, in fact I hate gulls! but the main differences between the two birds mentioned should be, the mantle colour, on LBBG it will be quite dark (although it varys) and the YLG is paler by comparison. Basically it starts pale for herring then Caspian is the next lightest, followed by YLG and then LBBG. There are other differences but thats the main one I work on. Not too good when it comes to mirrors etc, but if you look again at his photo you can see a definate difference in over all shape and size, and the white on the wingtips (known as the mirrors) is far more pronounced in the LBBG.
Hope that helps a bit:t:
Hope that helps a bit:t:
Last edited:
Hi all,
Yellow-legged Gulls can be difficult at some ages,but adults are usually not that hard.I would identify one using the following criteria:
1)mantle colouration:should be paler than most graellsii LBB,being roughly the same shade as Common Gull.
2)structure:the bill is often sturdy with a noticable gonydeal angle,and the head shape is less rounded than on LBB,also different to that of many Herrings.They tend to be quite bulky(esp.males from S.France),and often are noticably large,with a longer primary projection than Herring.The legs are longer than on LBB/Herring,but not thinner(c.f.Caspian)
3)orbital ring:this is red on YL Gull(as in LBB),orange in Herring.
4)amount of head streaking:in winter,most Herring and LBB have varying amounts of head streaking,whereas YL Gull is comparatively "white-headed"(NOTE:this is only valid up to about Jan,when many Herring and LBB start to lose this head streaking)
5)leg colour:as for LBB,easily rules out most Herrings(except for occasional birds from the Baltic(so-called "omissus" type))
6)amount of black on open wing:as a rule,there is more black and less white on the primaries of YL Gull,esp.in comparison with northern argentatus Herrings(which are about as dark above as YL Gull,but have more white in the primaries than our argenteus Herrings).
Caspian Gull also tends to be white-headed in winter,but differs as follows:
1)structure:a very distinctive small-headed and long-necked appearance,with no noticable gonydeal angle on the bill(looks long and parallel,often greenish-yellow in winter),and long thin legs,which tend to be an odd flesh-grey(can be yellowish,turn yellow in summer)
2)iris colouration:unlike in Herring,LBB or YL Gull,adult Caspian tends to have a dark iris(but beware subadult individuals of other large gulls,which may not yet have gained a pale iris)
3)wingtip pattern
ften shows a full white tip to P10(the outermost primary on the spread wing)Many northern argentatus also show this,but do not show the pale greyish "tongues" eating into the black along the inner webs of the primaries on the upperside of the wing.
I must add that I have never seen adult Caspian(1 juv.in Bulgaria only:they are rare here),and have only seen about 10 YL Gulls here,most of which were adults.
Hope this helps?
Harry
Yellow-legged Gulls can be difficult at some ages,but adults are usually not that hard.I would identify one using the following criteria:
1)mantle colouration:should be paler than most graellsii LBB,being roughly the same shade as Common Gull.
2)structure:the bill is often sturdy with a noticable gonydeal angle,and the head shape is less rounded than on LBB,also different to that of many Herrings.They tend to be quite bulky(esp.males from S.France),and often are noticably large,with a longer primary projection than Herring.The legs are longer than on LBB/Herring,but not thinner(c.f.Caspian)
3)orbital ring:this is red on YL Gull(as in LBB),orange in Herring.
4)amount of head streaking:in winter,most Herring and LBB have varying amounts of head streaking,whereas YL Gull is comparatively "white-headed"(NOTE:this is only valid up to about Jan,when many Herring and LBB start to lose this head streaking)
5)leg colour:as for LBB,easily rules out most Herrings(except for occasional birds from the Baltic(so-called "omissus" type))
6)amount of black on open wing:as a rule,there is more black and less white on the primaries of YL Gull,esp.in comparison with northern argentatus Herrings(which are about as dark above as YL Gull,but have more white in the primaries than our argenteus Herrings).
Caspian Gull also tends to be white-headed in winter,but differs as follows:
1)structure:a very distinctive small-headed and long-necked appearance,with no noticable gonydeal angle on the bill(looks long and parallel,often greenish-yellow in winter),and long thin legs,which tend to be an odd flesh-grey(can be yellowish,turn yellow in summer)
2)iris colouration:unlike in Herring,LBB or YL Gull,adult Caspian tends to have a dark iris(but beware subadult individuals of other large gulls,which may not yet have gained a pale iris)
3)wingtip pattern
ften shows a full white tip to P10(the outermost primary on the spread wing)Many northern argentatus also show this,but do not show the pale greyish "tongues" eating into the black along the inner webs of the primaries on the upperside of the wing.I must add that I have never seen adult Caspian(1 juv.in Bulgaria only:they are rare here),and have only seen about 10 YL Gulls here,most of which were adults.
Hope this helps?
Harry
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T0ny
Okillre Member
Harry - thanks for this masterly summary of the differences which we should look out for - I have high hopes of recording a 'lifer' by following your notes. I should say that I have had several YL Gulls 'pointed out' to me, but as I said in another thread, I like to be sure I have a better than even chance of identifying my own.
Tony
Tony
Craig Davies
Member
A masterly summary indeed Harry!. Like Tony I have had a number of YLG'S pointed out to me but recently I've managed to point out a few of my own to other Birders. Mantle colour does depend a lot on light with overcast days and bright sunshine both adding their own twist to the puzzle. Your I.D pointers give more depth to a Gull which is becoming more common, or should I say more wideley reported in the British Isles.
Craig ....
Craig ....
Hi Tony,
I wouldn't want to use anyone else's pics,and I have no photos of these 2 forms myself!Here are some useful links:
http://www.xs4all.nl/~calidris/gullindex.htm
(very few adult birds)
http://www.magikcircle.com/birds/image.asp?title_id=164&show_thumbnails=False
http://www.martinreid.com/gullinx.htm
(many unidentified/putative birds also on these sites)
http://www.surfbirds.com/ID Articles/casp.html
(Caspian Gull)
Harry
I wouldn't want to use anyone else's pics,and I have no photos of these 2 forms myself!Here are some useful links:
http://www.xs4all.nl/~calidris/gullindex.htm
(very few adult birds)
http://www.magikcircle.com/birds/image.asp?title_id=164&show_thumbnails=False
http://www.martinreid.com/gullinx.htm
(many unidentified/putative birds also on these sites)
http://www.surfbirds.com/ID Articles/casp.html
(Caspian Gull)
Harry
