This imm. large gull was photographed at Playa Bagdad, Tamaulipas,
Mexico on 13 September 1999 by John and Carol Gee. Given that
the '90s have seen the occurance on the Gulf Coast of LBBG (lots),
GBBG, Kelp Gull, KelpXHerring Gull hybrids, Western Gull and recently
Yellow-footed Gull, there would seem to be a number of possibilities
for the identity of this bird and its cohorts (see below); my
analysis is at the bottom of this page - please send me your
comments:
here are two more birds seen with the above bird; the observers
stated that these three birds tended to stay quite close together,
and all were on the same stretch of beach as an adult
Kelp Gull:
First let's try to age them; the palish eyes in September must
mean that these birds are not in their first year, as even YFGU
- which acquires some "adult-like" upperpart feathers
in the post-juvenile molt - would not be pale-eyed by its first
Fall. Even the largest four-year gulls would show fewer "first-year"
type feathers if they were in their third year - thus I feel that
these birds are First-Alternate/Second-Basic.
Statisically the most likley form is LBBG, but I feel this can
be ruled out because of the bill shape, general structure, and
solid-black tail. That tail rules out GBBG, and looks good for
WEGU or YFGU, but I feel that the intricate pattern of many of
the upperpart feathers is not right for either of these forms
(although the strong white trailing edge of the secondaries is
reminiscent of these types), and the pale eye in such young birds
does not look right for WEGU. It actually looks quite good for
KEGU, except that the "mantle gray" appears too pale,
and the legs may be too pink for this age.
Thus I feel that the best fit for these birds is KEGUxHEGU hybrid,
as all the anomolies can be explained by this combination - and
such birds are known to occur a short distance to the north.
