RHYXCHOPS MELANURA. 193 



410. RHYNCHOPS MELANURA, Sw. 

 (BLACK-TAILED SKIMMER.) 



Rhynchops nigra, Burm. La-Plata Reise, ii. p. 520 (Rio Parana) ; Scl et Salv. 

 P. Z. S. 1869, p. 634 (Buenos Ayres) ; iid. Nomencl p. 147 ; Durnford, Ibis, 

 1877, p. 203 (Buenos Ayres) ; White, P. Z. S. 1882, p. 628 (Buenos Ayres). 

 Rhynchops melanura, Saunders, P. Z. S. 1882, p. 522. 



Description. Above brownish black ; forehead and wing-band white ; tail 

 black : beneath white ; bill, apical half black, basal half orange ; feet red : 

 whole length 19*0 inches, wing 15*0, tail 5'0. 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) : 



" 1 here saw a very extraordinary bird, called the Scissor-beak (Rhyn- 

 chops 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, differ- 

 ently 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 



VOL. II. 



