Volume Ii Part 37 (2/2)

_Female_ similar.

_Hab._ Coasts of South America.

The Black-tailed Skimmer, which is common on the coasts of Brazil, migrates south in spring, following the course of the Plata river in its journey, and appearing in pairs or small flocks in the neighbourhood of Buenos Ayres during the month of October. Its chief breeding-ground is on the extensive mud-banks and islets at Bahia Blanca on the Atlantic coast. The return-migration occurs in March.

Darwin met with the Scissor-bill during his excursion up the Parana in October 1833, and speaks of it as follows (Nat. Journ. p. 161):--

”I here saw a very extraordinary bird, called the Scissor-beak (_Rhynchops nigra_). It has short legs, web feet, extremely long-pointed wings, and is of about the size of a Tern. The beak is flattened laterally, that is in a plane at right angles to that of a Spoonbill or Duck. It is as flat and elastic as an ivory paper-cutter, and the lower mandible, differently from every other bird, is an inch and a half longer than the upper. I will here detail all I know of the habits of the Scissor-beak. It is found both on the east and west coasts, between lat. 30 and 45, and frequents either salt or fresh water. The specimen now at the Zoological Society was shot at a lake near Maldonado, from which the water had been nearly drained, and which, in consequence, swarmed with small fry. I there saw several of these birds, generally in small flocks, flying backwards and forwards, close to the surface of the lake. They kept their bills wide open, and with the lower mandible half buried in the water. Thus skimming the surface, they ploughed it in their course; the water was quite smooth, and it formed a most curious spectacle to behold a flock, each bird leaving its narrow wake on the mirror-like surface. In their flight, they frequently twist about with extreme rapidity, and so dexterously manage, that with their projecting lower mandible they plough up small fish, which are secured by the upper half of their scissor-like bill. This fact I repeatedly saw, as, like Swallows, they continued to fly backwards and forwards, close before me.

Occasionally, when leaving the surface of the water their flight was wild, irregular, and rapid; they then also uttered loud, harsh cries.

When these birds are fis.h.i.+ng, the length of the primary feathers of the wings is seen to be quite necessary, in order to keep the latter dry.

When thus employed, their forms resemble the symbol by which many artists represent marine birds. The tail is much used in steering their irregular course.

”These birds are common far inland along the course of the Rio Parana; it is said they remain during the whole year, and breed in the marshes.

During the day they rest in flocks on the gra.s.sy plains, at some distance from the water. Being at anchor, as I have said, in one of the deep creeks between the islands of the Parana, as the evening drew to a close, one of these Scissor-beaks suddenly appeared. The water was quite still, and many little fish were rising. The bird continued for a long time to skim the surface, flying in its wild and irregular manner up and down the narrow ca.n.a.l, now dark with the growing night and the shadows of the overhanging trees. At Monte Video I observed that some large flocks during the day remained on the mud-banks at the head of the harbour, in the same manner as on the gra.s.sy plains near the Parana; and every evening they took flight direct to seaward. From these facts, I suspect that the _Rhynchops_ generally fishes by night, at which time many of the lower animals come most abundantly to the surface. M. Lesson states that he has seen these birds open the sh.e.l.ls of the _Mactrae_, buried in the sand-banks on the coast of Chile; from their weak bills, with the lower mandible so much produced, their short legs and long wings, it is very improbable that this can be a general habit.”

411. PHAeTHUSA MAGNIROSTRIS (Licht.).

(GREAT-BILLED TERN.)

+Sterna magnirostris+, _Burm. La-Plata Reise_, ii. p. 519 (Rio Parana); _Saunders, P. Z. S._ 1876, p. 643; _Barrows, Auk_, 1884, p. 316 (Entrerios). +Phaethusa magnirostris+, _Scl. et Salv.

Nomencl._ p. 147; _iid. P. Z. S._ 1871, p. 567; _Durnford, Ibis_, 1877, p. 200 (Buenos Ayres).

_Description._--Crown, ear-coverts, and nape black; mantle slate-grey, pa.s.sing into white at the tips of the secondaries; wing-coverts white; quills black; tail slate-grey; lores and entire underparts glossy white; bill yellow, with a greenish tinge at the base of under mandible; legs and feet olive-yellow: whole length 145 inches, wing 115. In the young the crown is grey; the mantle browner grey.

_Hab._ Coasts and rivers of South America.

This large-billed Tern, ”with a slightly forked tail, but amply developed feet,” is occasionally seen near Buenos Ayres.

Durnford tells us that he found it common at Baradero in April in small parties, and watched one flock for some time. These individuals kept circling over a mill-pond, which evidently held a good supply of small fishes; for they constantly kept darting into the water. This species, Durnford adds, has a note quite unlike that of any other Tern; it is nearly similar to the cry of the ”Tero-tero” (_Vanellus cayennensis_), for which he had often mistaken it.

412. STERNA MAXIMA, Bodd.

(GREAT TERN.)

+Sterna maxima+, _Scl. et Salv. Nomencl._ p. 147; _iid. P. Z. S._ 1871, p. 567; _Saunders, P. Z. S._ 1876, p. 655, et 1882, p. 521.

_Description._--Crown and crested nape black; neck, lores, throat, and underparts pure white; black pale grey; quills darker grey, with white on most of the inner webs; tail pearl-white; bill orange; legs and feet black: whole length 180 inches, wing 145. _Young_: darker on upper parts.

[Ill.u.s.tration: Head of _Sterna maxima_. (P. Z. S. 1871, p. 568.)]

_Hab._ Coasts of America from Ma.s.sachusetts to La Plata, and northwards to California.

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