150 BIRDS OF LA PLATA 
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CHILOE WIGEON 
Mareca sibilatrix 
Above black, on the neck barred across with white; feathers of 
the back and scapularies margined with white; head above and 
cheeks pure white; nape and back of the neck shining greenish 
purple ; wings brown, lesser wing-coverts white ; secondaries velvety 
black, white at the base ; beneath white, throat and fore-neck blackish ; 
upper breast black, with narrow white cross-bands; flanks stained 
with rusty rufous; bill and feet black; length 20, wing 10.3 inches. 
Female similar, but not so bright in colour. 
THE Chiloe Wigeon, as this duck has been usually 
called since its introduction and acclimatisation in 
England as an ornamental water-fowl, is the only 
species of the genus found in South America, and is 
most abundant on the pampas, where it is called 
by the country people Pato picaso or Pato overo 
(Piebald Duck) or Chirivi from its cry. It is a very 
handsome bird ; the upper plumage variegated with 
black, white, and grey; forehead, speculum, and 
under surface white; head and neck dark glossy 
green. It is resident, and is usually seen in small 
flocks of from a dozen to twenty birds, but sometimes 
as many as one or two hundred congregate together. 
They are wary and loquacious, strong on the wing, 
and frequently engage in a peculiar kind of aerial 
pastime. A small flock will rise to a vast height, 
often until they seem mere specks in the sky, or 
disappear from sight altogether; and at that great 
altitude they continue hovering or flying, sometimes 
keeping very nearly in the same place for an hour 
