212 BIRDS OF LA PLATA 
At the approach of coM weather the Dominican 
Gulls leave the sea-shore and wander inland and 
northward. At this season they are almost exclu- 
sively 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, 
hoarse sea-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 carcase; I have seen as many as five to six 
hundred Dominicans massed round a dead cow. 
ARGENTINE BLACK-HEADED GULL 
Larus maculipennis 
Head and nape brownish-black (in breeding dress) ; tail and under- 
parts 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 17, wing 11.5 inches. 
Tus common Black-headed Gull is found through- 
out the Argentine country, down to Chupat in Pata- 
gonia, and is exceedingly abundant on the pampas 
of Buenos Ayres, where it is simply called Gaviota 
(Gull). In the month of October they congregate 
in their breeding-places—extensive inland marshes, 
