Argentine Ornithology Volume Ii Part 39

(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 (Parana).

_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 160 to 170 inches, wing 1225.

_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 sh.o.r.es 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. PODICIPEDIDae, 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.

419. aeCHMOPHORUS MAJOR (Bodd.).

(GREAT GREBE.)

+Podiceps bicornis+, _Burm. La-Plata Reise_, ii. p. 520 (Rio Parana).

+aechmophorus major+, _Scl. et Salv. Nomencl._ p. 150; _Durnford, Ibis_, 1877, p. 203 (Buenos Ayres), et 1878, p. 405 (Centr.

Patagonia); _Barrows, Auk_, 1884, p. 316 (Entrerios); _White, P.

Z. S._ 1883, p. 433 (Buenos Ayres); _Withington, Ibis_, 1888, p. 473 (Lomas de Zamora). +Podiceps chilensis+, _Darwin, Zool.

'Beagle,'_ iii. p. 137 (Buenos Ayres). +Podiceps major+, _Scl. et Salv. Ex. Orn._ p. 190; _Gibson, Ibis_, 1880, p. 164 (Buenos Ayres).

_Description._--Above blackish; occipital crest divided, bronzy black; wide bar across the wing white: beneath white; chin dark ashy; neck, breast, and sides of belly (in adult) more or less red; bill yellowish; feet dark: whole length 210 inches, wing 80, tail 15.

_Hab._ South America.

This fine Grebe is said by Buffon to be from Cayenne, but we have never seen specimens from anywhere so far north. It was not obtained in Brazil by Natterer or Burmeister, but Azara met with it in Paraguay.

This Grebe is called in the vernacular _Macas cornudo_--the first word being the Indian generic name for the Grebes, while _cornudo_ signifies horned, from the bird's habit of erecting, when excited, the feathers of the nape in the form of a horn. The species is found throughout Eastern Argentina, from its northern limits to Central Patagonia, where Durnford found it common and resident. On the Rio Negro I found it abundant, and it was formerly just as common along the Plata river, but owing to its large size and the great beauty of its l.u.s.trous under plumage it is very much sought after and is becoming rare.

It is impossible to make this Grebe leave the water, and when discovered in a small pool it may be pursued until exhausted and caught with the hand; yet it must occasionally perform long journeys on the wing when pa.s.sing from one isolated lake to another. Probably its journeys are performed by night.

There is little diversity in the habits of Grebes, and only once have I seen one of these birds acting in a manner which seemed very unusual.

This Grebe was swimming about and disporting itself in a deep narrow pool, and showed no alarm at my presence, though I sat on the margin within twenty-five yards of it. I saw it dive and come up with a small fish about three inches long in its beak; after sitting motionless for a little while, it tossed the fish away to a considerable distance with a sudden jerk of its beak, and then at the instant the fish touched the water it dived again. Presently it emerged with the same fish, but only to fling it away and dive as before; and in this way it released and recaptured it about fifteen times, and then, tired of play, dropped it and let it escape.

Mr. Gibson has the following note on the breeding-habits of the Great Grebe, as observed at Ajo, near the mouth of Rio de La Plata:--"_P.

major_ breeds about the end of August, placing its nest in the thickest rushes of the swamp. The nest, built of wet water-weeds, is raised just above the level of the water; and I have twice seen the sitting bird hastily draw some weeds over the eggs before leaving them, on my approach. The clutch consists of three; and these are of the usual Grebe colour, generally much soiled and stained. They average 2-6/40 1-7/40, the length sometimes presenting a variation of 9/40, even in eggs of the same nest."

420. PODICEPS CALIPARaeUS, Less.

(BRIGHT-CHEEKED GREBE.)

+Podiceps caliparaeus+, _Darwin, Zool. Voy. 'Beagle,'_ iii. p. 136; _Scl. et Salv. Nomencl._ p. 150; _iid. Ex. Orn._ p. 190; _Durnford, Ibis_, 1877, p. 45 (Chupat), et 1878, p. 405 (Centr. Patagonia); _White, P. Z. S._ 1883, p. 43 (Cordova).

_Description._--Above dark greyish; front of head and neck behind pale cinereous; back of head and upper part of neck black; ear-coverts considerably elongated, golden brown: beneath, throat grey, paler than front of head; rest of under surface shining white; primaries greyish brown, the innermost tipped with white; secondaries more or less pure white, or dusky on outer webs: whole length 115 inches, wing 47. _Female_ similar.

_Hab._ Antarctic America, north to Cordova.

Darwin obtained examples of this beautiful Grebe at Bahia Blanca, where, he says, "it lives in small flocks in the salt-water channels extending between the great marshes at the head of the harbour." Durnford procured specimens on both visits to Chupat, where he found it common in the lagoons in all the valleys. It is also found, though not so abundantly, in the northern provinces of the Argentine Republic. White obtained a single example at Cosquin, near Cordova, in September 1882.

421. PODICEPS ROLLANDI, Quoy et Gaim.

(ROLLAND'S GREBE.)

+Podiceps rollandi+, _Scl. et Salv. Nomencl._ p. 159; _iid. Ex. Orn._ p. 190; _iid. P. Z. S._ 1868, p. 146; _Scl. P. Z. S._ 1872, p.

549 (Rio Negro); _Durnford, Ibis_, 1877, p. 45 (Chupat); _Gibson, Ibis_, 1880, p. 164 (Buenos Ayres); _White, P. Z. S._ 1883, p. 43 (Cordova); _Barrows, Auk_, 1884, p. 317 (Bahia Blanca).

_Description._--(_Summer plumage._) Above brownish black, with dark green reflexions; all the feathers below the neck narrowly margined with rufous; ear-coverts elongated, white at base with black tips, and more or less covering the downy white feathers of the sides of the head; outer half of primaries brownish grey, darker at tip; inner half and secondaries more or less pure white, some of the outer webs brownish or buff: beneath, neck and throat blackish brown, shading into chestnut, burned with dusky on the lower breast and rest of under surface. (_Winter plumage._) Above not so dark: beneath, throat white, neck dusky rufous; rest of under surface shining whitish buff, becoming dusky towards the vent. Whole length 118 inches, wing 54.

_Hab._ Antarctic America, north to Cordova.

Rolland's Grebe is said by Durnford to be "common in almost every pool and ditch" in Chupat. It is also common throughout Buenos Ayres, where the native name for it is _Macasito_.

Mr. Gibson gives the following details as to its nesting-habits:--"_Podiceps rollandi_ nests during the latter half of September and beginning of October. The nest is a slight construction of water-weeds, floating on the surface of the water, and only kept stationary by the surrounding rushes. Like _P. major_, it covers the eggs before leaving them. Five is the largest clutch of eggs I have taken; they are originally of a bluish-white colour, but after some time become covered with a brown incrustation of a chalky nature. The average measurement is 1-30/40 1-9/40; but there is a variation of 11/40 in length and 7/40 in breadth between my largest and smallest specimens."

Specimens of this Grebe were obtained near Cordova by White in 1882.

422. TACHYBAPTES DOMINICUS (Linn.).

(AMERICAN DABCHICK.)

+Podiceps dominicus+, _Burm. La-Plata Reise_, ii. p. 521 (Pampas); _Baird, Brew., et Ridgw. Water-B. N. A._ ii. p. 438. +Tachybaptes dominicus+, _Scl. et Salv. Nomencl._ p. 150; _Durnford, Ibis_, 1877, p. 203 (Buenos Ayres), et 1878, p. 405 (Centr. Patagonia); _White, P. Z. S._ 1882, p. 629 (Buenos Ayres); _Withington, Ibis_, 1888, p. 473 (Lomas de Zamora). +Sylbeocyclus dominicus+, _Scl. et Salv. Ex. Orn._ p. 190.

_Description._--Above dark brown, with blackish mottlings; wings grey, inner secondaries and under wing-coverts white: beneath pale whitish cinereous, chin and throat pure white; neck in front brownish; bill plumbeous, at base yellowish; feet black: whole length 100 inches, wing 40, tail 10. _Female_ similar, but not so bright.

_Hab._ Central and South America.

This representative of the well-known "Dabchick" of Europe is found throughout South and Central America. In the Argentine Republic, near Buenos Ayres, it is "resident and common in the lagoons and arroyos"

(Durnford, _l. s. c._), and likewise in the Territory of Chupat.

423. PODILYMBUS PODICEPS (Linn.).