Re: mantle color of ? Kelp Gull
Thomas Stock (TSTOCK@FMSHRC.GOV)
Thu, 18 Feb 1999 10:26:18 -0500
Harvey Mudd wrote: >>>Neither Marion nor I were able to convince
ourselves that we could be sure there was a constant distinguishable
difference in the dark tones of the upper parts of the two. [Kelp and
GBBG] >>>
I reported yesterday that I felt the mantle color of the Kelp Gull is very
similar to GBBG. My comparative view was from a great distance -
the two birds were flying well upriver from the Sandgates observation
area. Had this been my one and only view of the Kelp Gull, I would
have called it a GBBG. Its mantle was indistinguishable at that distance
(and in bright sun) from the GBBG.
Much has been written about this gull already. After seeing it
yesterday, I spent awhile studying my gull texts last night. I found
Harrison's guides singularly unhelpful on the key field mark - leg color.
The photo guide gives a good idea of the structure of the bird, but
the photos on the Internet are actually better. (By the way, I do not
have a copy of the Kelp Gull Field Notes. Has anyone given thought
to obtaining the necessary permissions, scanning that photo, and
posting it on the Net?) I found Harrison's plates in his older guide
of no use, but the text is somewhat helpful. I do not own the Large
Gulls video, but I intend to rectify that situation forthwith!
I found Grant very helpful, albeit only as a resource to rule out
the darker mantled LBBGs. I especially would call attention to Plates
264 and 269 showing L. f. intermedius alongside Yellow-legged Gulls.
The Maryland bird bears no resemblance whatsoever in terms of
structure to the intermedius birds pictured in these Grant plates.
Where the intermedius birds have a long profile, small head, and
relatively slender bill, the bird I saw yesterday has a shorter
profile and larger barrel chested appearance, larger head, and
thicker bill with more prounounced gonys.
As for L. f. fuscus, although this subspecies has been ruled out
by others, I would add that to my eye the Maryland bird has a
wider white trailing edge to the wing than the fuscus birds pictured
in Grant at Plates 290-293.
Now, if I can just sneak away from work again to study the bird
some more....
Tom Stock
Silver Spring