I cannot be sure if this bird from Bahrain in early March is a
Big Pale Heuglini-type or
a barabensis. Statisically
the odds favor the latter, but I feel that the following features
point to heuglini:- the molt score - none of the hundreds
of adult barabensis I saw were still growing P10, but a
handful of heuglini were at a similar stage to this bird
(and at least one bird had a much lower score); size and shape
of the bill/head (a lot of overlap here, but this bird is at least
in range for both forms); the bill base being slightly paler yellow
than the tip; the extensive flesh tones to the feet (on a bird
with relatively little black in the bill); the degree of darkness
to the underside of the secondaries and inner primaries (given
that the underwing coverts look very white in this exposure);
the slightly more-staggered pattern of black on the underside
of the primaries (like heuglini, barabensis tends
to have an almost solid black P10, but with the gray tongues of
P9 and P8 slightly more extensive and almost as long as each other).
Points in favor of barabensis are the apparently dark eye
(but the strong shadow may be affecting this) and the apparent
lack of nape-streaking (but we cannot see the center of the nape;
in early March some heuglini had streaking restricted to
the lower center of the nape, and a few were already without any
markings). I feel that if this is a heuglini then the mantle
tone, large double-mirrors, and rather limited black in the primaries
indicate the Big-Pale Heuglini-type:
Note: P10 looks to be all-dark at the base, but keep in mind that
it still has 2 - 3 inches still to grow, and thus may yet show
the classic small arc of dark gray on the inner web that is typical
of both heuglini and barabensis:
