(GREY-CAPPED GULL.)
+Larus cirrhocephalus+, _Scl. et Salv. Nomencl._ p. 148; _iid. P. Z.
S._ 1871, p. 578; _Durnford, Ibis_, 1877, p. 201 (Buenos Ayres);
_Barrows, Auk_, 1884, p. 316 (Entrerios); _Saunders, P. Z. S._
1878, p. 204. +Larus maculipennis+, _Burm. La-Plata Reise_, ii.
p. 518 (Paraná).
_Description._--Head (in breeding-plumage) grey, deepening in colour
on the nape and throat; tail and underparts white; mantle grey
(darker than in _L. maculipennis_); primaries black, with small
subapical white patches on first and second, and longer ones on the
outer webs of third to fifth near the base; _underwing slate-grey_;
bill, legs, and feet crimson to orange-red: length 16·0 to 17·0
inches, wing 12·25.
_Hab._ South Brazil, Uruguay, and La Plata, also coast of Peru.
The Grey-capped Gull is found on the Rio de la Plata, and as far north
as Concepcion on the Uruguay in winter, where Mr. Barrows observed it in
immense flocks frequenting the "_Saladeros_."
Durnford gives us the subjoined account of this species:--"I have not
observed this bird to the south of Buenos Ayres, but have constantly
seen it from March to July to the north of the city. Unlike _Larus
maculipennis_, it never wanders inland, but frequents the shallow shores
of the La Plata, feeding on dead fish or offal, and flocking round the
fishermen when they are hauling their nets to get a share of the spoil.
As a rule, this species does not mix with _Larus maculipennis_, though
now and then they are seen together; but all the flocks or parties I
have observed when flying from one spot to another have always been
composed of birds of its own kind. Adults, after once attaining their
pearl-grey hood, never lose it, though in winter it becomes rather
lighter, and those with white heads are immature birds, which do
not attain their full plumage till after their second moult. I have
seen many birds throughout May and June of the present year with
well-defined dark grey hoods. Some specimens, when first killed, have
a delicate faint pink tinge on their underparts, also observed in _L.
maculipennis_, which, however, quickly fades after death. The colour of
the iris varies a good deal in different examples, being pale grey, grey
with a tinge of yellow, and grey with a tinge of light wood-brown. This
is probably attributable to age. The narrow rim of naked skin round the
eye is dark coral-red; legs and feet the same, but of a duller shade;
beak rather darker than the legs."
Order XVII. PYGOPODES.
Fam. LI. PODICIPEDIDÆ, or GREBES.
The Grebes, although perhaps more especially a development of the
Arctic lands, are sparingly represented all through the tropics, and
reappear in augmented numbers south of the Antarctic circle. Within the
Neotropical Region nine to eleven species are met with, of which five
are found inside our limits. Three of these are peculiar Patagonian
species, the other two are widely spread over America.