Larus ridibundus Linnæus, Syst. Nat. ed. 12 (1766), 1, 225;
Saunders, Cat. Birds Brit. Mus. (1896), 25, 207; Sharpe, Hand-List
(1899), 1, 140; Oates, Cat. Birds' Eggs (1901), 1, 208; McGregor
and Worcester, Hand-List (1906), 21.
Luzon (Jagor, Murray, McGregor); Mindanao (Murray,
Goodfellow). Europe, northern Asia, Africa, and Indian Ocean;
China to Malay Archipelago in winter.
"Adult male in breeding plumage.--Hood coffee-brown; gray mantle,
white tail, and white under surface tinged with evanescent roseate;
pattern of outer primaries chiefly white, with black tips, and black
margins to inner webs; shafts of three outer quills white; outermost
quill white, with a narrow black line along the greater part of outer
web (touching the shaft in all except very old birds), a black tip,
and a blackish edge to the inner margin; second quill similar, but with
merely a short hairline of black on the outer web; third quill with
a trifle more black running upward from the black tip along the outer
web; fourth quill similar, but with a gray center to inner web; fifth
quill white on both webs, and with a minute white tip; sixth similar,
but the tip gray and broader, so that the black becomes a subterminal
bar; seventh similar, but with less and fainter black; upper primaries
gray; secondaries paler gray, without conspicuous margins. Bill,
tarsi, and toes lake-red; iris hazel. Length, 394 to 406; culmen,
46; wing, 298 to 305; tail, 127; tarsus, 43; middle toe with claw, 39.
"The female is undoubtedly smaller as a rule, though there are
exceptions.
"Adult in winter.--Similar, but without a hood; merely a little
grayish on the occiput, and blackish on the auriculars. In vigorous
birds the indications of a hood reappear in autumn, soon after the
completion of the molt, which is in August; but cold weather, combined
with a scarcity of nutritive food, arrests the development, and it
is not usual to see birds with fully complete hoods till February,
though there are many exceptions. A female (by dissection) obtained
in the shore-nets at Wells, Norfolk, on November 10, has the under
parts, and even the shafts and webs of the primaries, suffused with
a beautiful salmon-pink, but this also must be considered unusual.
"Nestling.--Buffish to brown, darkest on the upper parts, spotted
and streaked with umber and black on the back, head, and throat.
"Young.--Forehead white, rest of head chiefly grayish brown; upper
surface warmer brown, with gray lower wing-coverts; secondaries with
blackish centers and white borders; the three outer primaries black
on outer webs and at the tips and margins of inner webs, but the
centers white, except the outermost, in which there is for a time
a dark line inside the shaft; in the succeeding primaries the dark
color increases ascendingly on the inner webs, while from the fifth
the outer webs are pale gray to brownish, with a little white at tips;
tail-feathers white, with a band of blackish brown; under surface dull
white. Bill dull yellow, passing into black at the angles; tarsi and
toes dull reddish yellow. The brown color is soon lost on the back,
which has become gray by December.
"Immature.--Like the adult, with a few brown markings left on the upper
wing-coverts, and more black on the outer webs of the primaries. More
or less of a brown hood is assumed when the bird is barely a year old,
and the band on the tail is lost by the following autumn, when the new
primaries appear, with, as has been said, a larger proportion of black
than in the adult; in fact the duration of the immature phase is very
short. The bird does not breed until the following, or second spring.
"Occasionally the black from the margins of the inner webs of the
three outer quills runs in and reaches the shafts, much encroaching
upon the usual white centers, though not to the same extent on both
wings of the same bird. This is noticeable in two examples obtained
at Dinapur in December." (Saunders.)
This small gull is often abundant about Manila Bay but does not remain
throughout the year.