140 BIRDS OF LA PLATA 
flowing into it, and northwagls to Paraguay. Along 
this great waterway it is to some extent a migratory 
species, appearing in spring in Buenos Ayres in very 
large numbers, to breed in the littoral marshes and 
also on the pampas. They migrate principally by 
night, and do not fly in long trains and phalanxes 
like other Ducks, but in a cloud; and when they 
migrate in spring and autumn the shrill confused 
clangour of their many voices is heard from the 
darkness overhead by dwellers in the Argentine 
capital; for the Ducks, following the eastern shore 
of the sea-like river, pass over that city on their 
journey. Northwards this Duck extends to Central 
Brazil; from the northern half of the southern 
continent and from Central America it is absent ; 
but it re-appears in Mexico. Commenting on these 
facts Messrs. Sclater and Salvin write: ‘* Singular 
as this distribution is, it is still more remarkable 
when we consider that there appear to exist no 
tangible grounds for separating the American bird 
from that called D. major by Jerdon, which ranges 
throughout the peninsula of India and is also found 
in Madagascar !”’ 
The Whistling Duck, in its chestnut and fulvous 
plumage, is a handsome bird and somewhat singular 
in appearance, especially when seen in a large body 
on the ground. When out of the water they crowd 
close together, and when disturbed stand up craning 
their necks, looking strangely tall on their long blue 
legs. While thus watching an intruder they are 
silent, and the sudden ringing chorus of whistling 
