This large Tern seems to occur on the Rio Parana, according to Azara.

It is certainly found in Southern Brazil, where Mr. Rogers obtained a series of specimens now in the collections of Messrs. Salvin and G.o.dman and of Mr. H. Saunders.

413. STERNA TRUDEAUII, Aud.

(TRUDEAU'S TERN.)

+Sterna trudeauii+, _Scl. et Salv. Nomencl._ p. 147, _iid. P. Z. S._ 1871, p. 570; _Durnford, Ibis_, 1877, p. 200 (Buenos Ayres); _Saunders, P. Z. S._ 1876, p. 660. +Sterna frobeenii+, _Phil. et Landb. Wiegm. Arch._ 1863, pt. i. p. 125 (Chili).

_Description._--Above light grey; head white, with a dark transocular line on each side; rump white: beneath light grey; bill black, base and tip yellow; feet yellow: whole length 125 inches, wing 100. The young are pure white below, and have darker quills.

_Hab._ Coasts of S.E. Brazil, Argentina, and Chili.

This beautiful Tern, peculiar for its white head in the adult dress, was observed by Durnford on Flores Island in the Rio de la Plata, and in other places on the coast of the Argentine Republic. One was obtained near Punta Lara, in October 1876; and many more since by Mr. E. Gibson, Commander MacFarlane, and others.

414. STERNA HIRUNDINACEA, Less.

(Ca.s.sIN'S TERN.)

+Sterna hirundinacea+, _Saund. P. Z. S._ 1876, p. 647; _Durnford, Ibis_, 1878, p. 404 (Centr. Patagonia). +Sterna ca.s.sini+, _Scl.

et Salv. Nomencl._ p. 147; _iid. P. Z. S._ 1871, p. 570; _Durnford, Ibis_, 1877, p. 201 (Buenos Ayres).

_Description._--Head and nape black; mantle and wings grey, darker on the quills; rump white; tail pearl-white, darker on the outer streamers; underparts greyish white; bill blood-red; feet orange-crimson: whole length 150 inches, wing 115. _Young_: streaked on the head and mottled on the upper parts with blackish.

_Hab._ Patagonia, Chili, Peru, Argentina, Brazil, and Falkland Islands, up to Rio.

This is a black-headed Tern with a blood-red bill, which is found abundantly on the coast of Patagonia, and extends up the Atlantic coast to Rio. It was noticed by Durnford near Buenos Ayres, and found breeding by the same excellent observer at Tombo Point, about sixty miles to the south of Chupat, in December 1877. He tells us:--

"I was prepared when I visited this place in December to see a considerable quant.i.ty of birds; but the number that met my eyes fairly staggered me. Their nests covered an area about 150 yards square. Allowing three nests and five eggs for every square yard (a very moderate computation, it being difficult to walk without treading on the eggs), we arrive at the extraordinary number of 67,500 nests, 135,000 birds, and 112,500 eggs; and, wonderful as these figures may appear, I feel sure that I have rather understated than overstated the numbers. The nests were mere hollows in the fine gravel or shingle, and contained one, two, and sometimes three eggs. The latter generally have the appearance of the eggs of the Sandwich Tern, though of course smaller; and out of many hundreds I did not see two alike."

415. STERNA SUPERCILIARIS, Vieill.

(EYEBROWED TERN.)

+Sterna superciliaris+, _Scl. et Salv. Nomencl._ p. 147; _iid. P. Z.

S._ 1871, p. 571; _Durnford, Ibis_, 1877, p. 201 (Buenos Ayres); _White, P. Z. S._ 1882, p. 628 (Misiones); _Saunders, P. Z. S._ 1876, p. 662. +Sterna argentea+, _Burm. La-Plata Reise_, ii. p.

519 (Parana).

_Description._--Forehead and underparts white; loral stripe, head, and nape black; back, rump, inner primaries, and inner web of tail pale slate-grey; outer primaries blackish; bill yellow; legs and feet olive-yellow: whole length 85 inches, wing 70. In the young bird the crown is grey.

_Hab._ The large rivers and the coast on the east side of South America.

This is a little Tern, belonging to the same group as the European _Sterna minuta_, with a uniform pale yellow bill. Durnford met with it at Baradero, and says that it frequents shallow inland lagoons and small streams, but is also found on the Rio de la Plata. Dr. Burmeister obtained it on the Parana, and White at Itapua, Misiones. Saunders shot it on the Huallaga, in Peru, 2800 miles inland.

416. LARUS DOMINICa.n.u.s, Licht.

(DOMINICAN GULL.)

+Larus dominica.n.u.s+, _Scl. et Salv. Nomencl._ p. 148; _iid. P. Z. S._ 1871, p. 576; _Durnford, Ibis_, 1877, p. 45 (Chupat) et p. 201 (Buenos Ayres), et 1878, p. 405 (Chupat); _Barrows, Auk_, 1884, p. 316 (Pampas); _Saunders, P. Z. S._ 1878. p. 180; _Withington, Ibis_, 1888, p. 472 (Lomas de Zamora). +Larus vociferus+, _Burm.

La-Plata Reise_, ii. p. 518 (Buenos Ayres).

_Description._--Mantle brownish-black; primaries black, with white tips, and a subapical patch in old birds; rest of plumage white; bill yellow, orange at angle of lower mandible; legs and feet olive: whole length 210-220 inches, wing 170-180. _Young_ mottled brown.

_Hab._ Both coasts of South America, from Peru on the west and Rio on the east, to Patagonia and Falkland Islands.

The Dominican Gull, which belongs to the same section of the group as the well-known Black-backed Gulls of Europe, is common throughout the Plata district in winter, from April to August. During the summer months it confines itself to the Atlantic coast, and breeds in large numbers in the neighbourhood of Bahia Blanca, on the extensive sand-banks and mud-flats there; and in other suitable localities further south.

Durnford found it nesting at Tombo Point, sixty miles south of the Chupat river.

At the approach of cold weather the Dominican Gulls leave the sea-sh.o.r.e and wander inland and northward. At this season they are exclusively flesh-eaters, with a preference for fresh meat; and when the hide has been stripped from a dead cow or horse they begin to appear, vulture-like, announcing their approach with their usual long hoa.r.s.e pelagic cries, and occasionally, as they circle about in the air, joining their voices in a laughter-like chorus of rapidly-repeated notes. Their winter movements are very irregular; in some seasons they are rare, and in others so abundant that they crowd out the Hooded Gulls and Carrion-Hawks from the carca.s.s; I have seen as many as five to six hundred Dominicans ma.s.sed round a dead cow.

417. LARUS MACULIPENNIS, Licht.

(SPOT-WINGED GULL.)

+Larus maculipennis+, _Scl. et Salv. Nomencl._ p. 148; _Durnford, Ibis_, 1877, p. 202 (Buenos Ayres), et 1878, p. 405 (Centr.

Patagonia); _White, P. Z. S._ 1882, p. 628 (Buenos Ayres); _Saunders, P. Z. S._ 1878, p. 201; _Withington, Ibis_, 1888, p.

472 (Lomas de Zamora). +Larus serra.n.u.s+, _Burm. La-Plata Reise_, ii. p. 519. +Larus cirrhocephalus+, _Scl. et Salv. P. Z. S._ 1868, p. 146 (Buenos Ayres); _Hudson, P. Z. S._ 1871, p. 4.

_Description._--Head and nape brownish-black (in breeding-dress); tail and underparts white; mantle pale grey; primaries black or dark grey, tipped with white, and with large elongated white patches on the outer portions of first to fifth, followed by a subapical _black bar_ (in _L. glaucodes_ the lower portion is _white_): underwing _pale grey_; bill, legs, and feet blood-red: length 160-170 inches, wing 115.

[Ill.u.s.tration: Three outer primaries of adult SPOT-WINGED GULL.

(P. Z. S. 1878, p. 202.)]

_Hab._ Southern Brazil, Uruguay, and La Plata.

This common Black-hooded Gull is found throughout the Argentine country, down to Chupat in Patagonia, and is exceedingly abundant on the pampas of Buenos Ayres, where it is simply called _Gaviota_. In the month of October they congregate in their breeding-places--extensive inland marshes, partially overgrown with rushes. The nests are formed of weeds and rushes, placed just above the water and near together, several hundreds being sometimes found within an area of less than one quarter of an acre. The eggs are four in number, large for the bird, obtusely pointed, of a pale clay-colour, thickly spotted at the big end and spa.r.s.ely on the other parts with black.

Every morning, at break of day, the Gulls rise up from their nests and hover in a cloud over the marsh, producing so great a noise with their mingled cries that it can be heard distinctly at a distance of two miles. The eggs are considered a great delicacy, resembling those of the Plover in taste and appearance, and are consequently much sought after, so that when the locality near which a gullery is situated becomes inhabited the birds have no chance of rearing their young, as the boys in the neighbourhood ride into the marsh every morning to gather the eggs. The Gulls are, however, very tenacious of their old breeding-places, and continue even after years of persecution to resort to them.

The young birds are of a pale grey colour, mottled with dull brown, and have a whining querulous cry. The plumage becomes lighter through the autumn and winter, but it is not until the ensuing summer, when the dark brown nuptial hood is a.s.sumed, that the young birds acquire the perfect plumage--soft grey-blue above, and the white bosom with its lovely pink blush.

As soon as the young are able to fly the breeding-place is forsaken, the whole concourse leaving in a body, or scattering in all directions over the surrounding country; and until the following summer their movements depend entirely on food and water. If the weather is dry the Gulls disappear altogether; and if gra.s.shoppers become abundant the country people wish for rain to bring the Gulls. When it rains then the birds quickly appear, literally from the clouds, and often in such numbers as to free the earth from the plague of devastating insects. It is a fine and welcome sight to see a white cloud of birds settle on the afflicted district; and at such times their mode of proceeding is so regular that the flock well deserves the appellation of an army. They sweep down with a swift graceful flight and settle on the earth with loud joyful cries, but do not abandon the order of attack when the work of devouring has begun. The flock often presents a front of over a thousand feet, with a depth of sixty or seventy feet; all along this line of battle the excited cries of the birds produce a loud continuous noise; all the birds are incessantly on the move, some skimming along the surface with expanded wings, others pursuing the fugitives through the air, while all the time the hindmost birds are flying over the flock to alight in the front ranks, so that the whole body is steadily advancing, devouring the gra.s.shoppers as it proceeds. When they first arrive they seem ravenously hungry, and after gorging themselves they fly to the water, where after drinking they cast up their food and then go back to renew the battle.

In spring these Gulls come about the farms to follow the plough, filling the new-made furrows from end to end, hovering in a cloud over the ploughman's head and following at his heels, a screaming, fighting crowd. When feeding they invariably keep up a great noise. Wilson's expression in describing a northern species, that its cry "is like the excessive laugh of a negro," is also descriptive of the language of our bird. Its peculiar cry is lengthened at will and inflected a thousand ways, and interspersed with numerous short notes, like excited exclamations. After feeding they always fly to the nearest water to drink and bathe their feathers, after which they retire to some open spot in the neighbourhood where there is a carpet of short gra.s.s. They invariably sit close together with their bills toward the wind, and the observer will watch the flock in vain to see one bird out of this beautiful order. They do not stand up to fly, but rise directly from a sitting posture. Usually the wings are flapped twice or thrice before the body is raised from the ground.

In some seasons in August and September, after a period of warm wet weather, the larvae of the large horned beetle rise to the surface, throwing up little mounds of earth as moles do; often they are so numerous as to give the plains, where the gra.s.s has been very closely cropped, the appearance of being covered with mud. These insects afford a rich harvest to the Spur-winged Lapwing (_Vanellus cayennensis_), which in such seasons of plenty are to be seen all day diligently running about, probing and dislodging them from beneath the fresh hillocks. The Gulls, unprovided with a probing beak, avail themselves of their superior cunning and violence to rob the Lapwings; and I have often watched their proceedings for hours with the greatest interest.

Hundreds of Lapwings are perhaps visible running busily about on all sides; near each one a Gull is quietly stationed, watching the movements of its intended dupe with the closest attention. The instant a great snow-white grub is extracted the Gull makes a rush to seize it, the Lapwing flies, and a violent chase ensues. After a hundred vain doublings the Plover drops the prize, and slopes toward the earth with a disappointed cry; the pursuer checks his flight, hovers a moment watching the grub fall, then drops down upon it, gobbles it up, and hastens after the Lapwing to resume his watch.

Many of these Gulls haunt the estancias to feed on the garbage usually found in abundance about cattle-breeding establishments. When a cow is slaughtered they collect in large numbers and quarrel with the domestic poultry over the offal. They are also faithful attendants at the shepherd's hut; and if a dead lamb remains in the fold when the flock goes to pasture they regale on it in company with the Chimango. The great _Saladeros_, or slaughter-grounds, which were formerly close to Buenos Ayres, are also frequented by hosts of these neat and beautiful scavengers. Here numbers may be seen hovering overhead, and mingling their excited screams with the bellowing of half-wild cattle and the shouts of the slaughterers at their rough work; and at intervals, wherever a little s.p.a.ce is allowed them, dropping themselves on to the ground, which reeks with blood and offal, and greedily s.n.a.t.c.hing up whatever morsels they can on the instant, and yet getting no stain or speck on their delicate dress of lily-white and ethereal blue.

On the open pampas their curiosity and anger seems greatly excited at the appearance of a person on foot; no sooner has the Gull spied him than it sweeps toward him with a rapid flight, uttering loud indignant screams that never fail to attract all of its fellows within hearing distance. These all pa.s.s and repa.s.s, hovering over the pedestrian's head, screaming all the time as if highly incensed, and finally retire, joining their voices in a kind of chorus and waving their wings upwards in a slow curious manner; but often enough, when they are almost out of sight, they suddenly wheel about and hurry back screaming, with fresh zeal, to go through the whole pretty but annoying performance again.

418. LARUS CIRRHOCEPHALUS, Vieill.