Wednesday 26 July 2017

Gropper and Questionable YLG


I'm really not keen on this bird. I suppose it has to be a juvenile Yellow-legged Gull but there are several niggles for me and I'd be interested to hear other peoples' opinions. The first impression for me was of a grey, fairly standard-looking Herring Gull. It was only when I saw the tertials that I realised I needed to scrutinise it further. Viewing was hampered by low light levels and heavy rain, which may account for the lack of contrast normally shown for YLGs, so I just rattled off a load of photos and tried to get flight views. Once in the air it seemed fine for YLG - bright white tail base with a neat jet-black tail band and nice dark wings with a faint inner-primary window - completely wrong for both Herring and Lesser Black-backed Gull.
Structurally it's arguably a better fit for Lesser Black-backed gull - small size, small bill and long wings, but flight views ruled that out. There are no newly moulted scapulars, the greater coverts aren't the best and there's a bit too much of a buffy wash to the wing coverts for my liking. Further more the legs look dull, but again this could be down to lighting conditions. I could be over-thinking this bird but I suppose it has to be YLG.
Offshore I managed just 1 Mediterranean Gull, 1 Little Egret, c20+ Common Scoter and 5 Common Tern. A Redshank and Whimbrel touched down briefly on Maer Rocks.
Mudbank produced c20+ Common Tern, eight Mediterranean Gulls, a Common Sandpiper and a Teal amongst 60+ Mallard.
My first autumn passerine migrant was a Grasshopper Warbler - a typically skulking individual up on Orcombe Point, near the Geoneedle - seen several times but never still long enough to photograph.

 
 
This photos shows there are in fact dark bases to the greater coverts and the tertials are dark with limited pale markings around the tips. Better for YLG than Herring and Lesser Black-backed.


In this appalling shot you can see a faint 'window' in the inner primaries and a dark bar in the wing created by dark bases to the greater coverts. The tail area is good for YLG.


 

Little Egret - Mudbank

 
 Teal with Mallard. It's always good to see wildfowl numbers starting to build at this time of year. Large numbers of Mallard always harbour the possibility of something else in with them.
 

3 comments:

  1. Not sure what to make of that one Matt, for me closer to LB-bG despite the weak inner primmary window (LB-bG can show this I believe to a certain degree). The whole jizz of the bird just does not fit with YLG, small rounded head, small bill, legs a bit short, too much brown mottling in body plumage, rather too buffy in scaps and wing coverts, and as you say legs too dull (YLG always seem to stand out with their clean pale pink legs , due to earlier breeding). Also the Greater covert bar is quite extensive up the wing to the inner Grt Cvrts, perhaps better for LB-bG. For me the black in the tail is too extensive YLG are normally rather narrower in the centre and more often than not very limited black in the outer tail feathers. Of course there is variation in all individual juv gulls but I feel the variation would be better fit for for a paler juv LB-bG.

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  2. Hi Matt, I agree with Mike this is surely a LBB for all the reasons he gives. Also looks rather fresh, not conclusive of course but, as you know, YLG nearly always a lot more worn by now.

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  3. Hi Mike, Hi Tim - yep sure you're right. Many thanks. Matt

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