BLACK-NECKED SWAN 137 
Buenos Ayres and in Patagonia, and ranges south 
to the Magellan Straits and the Falklands. As a rule 
they are seen in small flocks, but sometimes as many 
as two or three hundred congregate together. They 
are heavy birds and rise with difficulty, and fly 
rapidly and with great violence, like all heavy-bodied 
short-winged species; but in no other very large 
bird with which I am acquainted do the wings 
produce so loud a rushing sound. In quiet places 
the beating of their wings can be heard distinctly 
when the birds are no longer in sight, although, 
owing to their large size, the eye can follow them 
very far. Gauchos sometimes capture them by 
suddenly charging down the wind upon them, 
uttering loud shouts which greatly terrify the birds, 
and when they attempt to rise with the wind they 
only flap along the ground and are easily knocked 
over. A gaucho of my acquaintance one day caught 
three out of a flock of six in this way; but a very 
strong wind favoured him, and the birds were at 
some distance from the water, and allowed him to 
come near before making the sudden charge. 
According to Mr. Gibson, who has observed their 
breeding-habits, they begin to nest in July—just 
after the winter solstice. The nest is always placed 
among thick rushes growing in deep water, and the 
Swan invariably swims to and from her nest. It is 
built up from the bottom of the swamp, in some 
instances four or five feet deep, and rises a foot 
and a half above the surface. The top of the nest 
measures about two feet across, with a slight hollow 
