112 
a loop of the windpipe barely enters the sternum. A little later in life it penetrates 
farther and makes a sharp angular return about halfway back to the sternum. At 
maturity the loop extends to the rear of the sternum and widens with age until it 
occupies the whole rear end of the sternum floor and even overhangs it, making a loop 
3} inches or more across. 
Field Marks. As a Swan, by size and complete whiteness. In flight, Swai carry 
their long neck outstretched like Cranes, but do not thrust out long legs behind. 
The presence of a yellow spot in front of the eye is indicative of this species, but its absence 
is of little import. The best means of separation from the Trumpeter in life is probably 
the voice, that of the Trumpeter being considerably deeper, more sonorous, and of a 
totally different quality. Recognition of this, however, requires familiarity with the 
voices of both species. 
Nesting. On the ground, nest of grasses, moss, etc., lined with down. 
Distribution. Breeds on the Arctic coast and islands west of Hudson bay. During 
migration passes through^the interior of the continent, rare on the coasts. 
Figure 145 
Longitudinal section through sternum of Whistling Swan; 
scale, 
Owing to its extreme wariness and its breeding far in the north the 
Whistling Swan has not been seriously reduced in numbers during the 
past generation. Its larger relative, the Trumpeter, whose breeding 
grounds, within the borders of settlement, were early disturbed, is now 
on the verge of extinction. Because of the great difficulty of telling the 
two Swans apart, the Migratory Birds Convention Act has declared a close 
season in both of them, in an attempt to save the last few Trumpeter 
swans from extermination. 
Swans rarely come into shallow marshes where cover may hide the 
sportsman. They are seldom seen except in dense white masses like ice 
floes far out in the open water, or in flocks flying high overhead and beyond 
the reach of guns. Their regular migration is generally by night and 
usually silent, though sometimes extremely noisy. To such habits as 
these is probably due the fact that few, even of our most experienced 
sportsmen, know the Swan in life, and fewer still can boast of having 
taken it. Though flocks of hundreds appear annually on lake St. Clair 
not more than two or three individuals were taken there each year before 
the closed season was declared. 
The species also occurs in large numbers on Niagara river where on 
misty or foggy nights in the spring they often drift down with the current 
into the swift, rough waters of the rapids and are carried helpless over the 
