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Re: mystery gull on outer banks



Hi to all,

Well, all description suggests one of the bird from Lesser Black-backed
Gull complex (Larus fuscus graelsii, L.f.intermedius  not including L.
(fuscus) heuglinii which is too far and L.f.fuscus which is blackish
with commonly seen rather worm tinge to the upperparts).
Some females of Lesser B-b are noticeably small and slender looking bird

not much bigger than european Common Gull (L. canus). They have fairly
narrow and slender bill comparing to Herring Gulls (European one L.
argentatus argentatus and local L (a.) smitsonianus).  The silhouette is

very characteristic with rather long primary projection, somewhat short
legs and in most cases (females) with nice looking rounded head. The
mantle color is fairly variable and cover a few numbers on Kodak color
scale, but in general is much darker than Ring-billed and Herring Gull
mantle. As far as "no white in wing tips" it is possible that bird may
not show white due to wear (Lesser B-b Gulls have rather small white
wing tips to outermost primaries which gone fairly quickly). I haven't
seen any LB-b with at least just a very little white mirror near the tip

of P10. However it could be overlooked in farther distance and bad
weather. Furthermore birds in 4th or even 5th calendar year (subadults)
show no white "mirrors" on P10, and 4th y. birds may have in winter
almost grayish upper wing (with just a tinge of brown color on primaries

and greater coverts and pure white tail. Underwing of Lb-b Gull looks
fairly dark due to large area of blackish outer primaries, much, much
larger than in Herrings, Ring Billed and Greater Black-backed Gulls. In
addition trailing edge to the wing in LB-b is very wide white line which

merges and getting very narrow on inner primaries.
The eye should be rather light but some individuals has rather dark eye
appearance from farther distances in bed light (yellow with many reddish

dots on iris). Subadults have darker eyes.
Legs color is the most tricky, but I have seen some LB-b gulls with not
yellow legs, varying from washed yellowish to even dull pinkish. legs
and bill color vary in a season according to breeding cycle being the
most bright (yellow in that case) in and of April, May (hormones...).
However subadults birds may show no yellow colored legs and bills  at
all.
However I wouldn't say I was 100%  Lesser Black-backed Gull, it is just
a suggestion of 4-5 calendar year birds of that species. They occur on
that side of the Atlantic fairly often (wintering on the opposite site
in Western Africa.

Mike



bruce young wrote:

> After finding the black-headed gull at mattamuskeet
> saturday, the Chapel Hill Bird club trip was feeling
> pretty smug about its gull-identifying capabilities,
> but of course pride goeth before a fall.
> On the beach just south of the Rodanthe pier this
> morning, we spotted a gull sitting on the sand. The
> bird was slightly larger than nearby Ring-bills and
> his mantle and wings were very dark grey (see the
> Yellow-footed Gull Adult picture in national
> geographic for the approximate color, that is just a
> color approximation not an ID suggestion). He had dark
> smudging around the eye and top of the head and around
> the back of his neck, with a white space in between.
> The eye was probably dark but it was hard to tell. The
> bill was long and slender, and split about 50/50
> between a dark end and a pale (not yellow) near end.
> The wingtips were black with no white mirrors at all.
> The trailing edge of the wing was a fairly broad band
> of white (showing as an arc between the primaries and
> the rest of the wing in the seated bird, I dont know
> the right terminology for that).
> We studied for about 5 minutes and were going to move
> closer (we were about a hundred fifty yards away) when
> two people and a dog walking on the beach spooked the
> bird. When it stood we saw that the legs were pale
> pink/flesh colored and the final confusing straw was
> that the tail was completely white, not even a speck
> of black.
> As it flew off (away from us of course) we could see
> that the underwing was darkish (it was hard to see)
> and the tips were black, again no white at all.  There
> was little contrast between the dark upperwings and
> black wing tips with no separation between.  The wings
> were not strikingly broad or narrow but it was hard to
> tell as he flew directly away.
> I have presented no suggestions as to ID because, to
> be honest, we had no idea.  Every possible ID we came
> up with had serious deficiencies. So here is the
> description for those with more gull knowledge to
> think about. Please post suggestions to the list.
> P.S. The group included Doug Shadwick, Judy Murray,
> Jill Froening, Karen Bearden, and myself.
> Bruce Young
> young715@yahoo.com
> durham NC.
>
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--
************************************************
Michal Skakuj  Ph.D.
4600 University Drive # 1312
Durham, NC 27707
phone, fax: (919) 402 9961