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condemned on suspicion, circumstantial evidence, or individual examples, 
but only after thorough investigation and proof of their destructiveness. 
The Migratory Birds Convention, on proper application, affords relief against 
birds that are doing serious damage, and if an examination by qualified 
investigators shows that valuable interests are being seriously injured, 
permits for necessary destruction can be obtained. 
129. American Merganser, saw-bill, goosander, sheldrake, shelduck. 
Mergus americanus. L, 25. 
Distinctions. Male: much similar to next species but larger and of heavier build 
throughout, without crest or reddish breast band and with more white less interrupted 
with black on flank, wings, and neck. The delicate 
salmon tint of the underbody is present only in the 
highest plumage and quickly fades to white in speci- 
mens. Female and young male are alike and not dis- 
tinguishable from parallel plumages of the Red-breasted 
Merganser except by careful study of details. The 
head is generally a deeper brown and stops with a sharp 
line where it meets the grey of the lower neck. The 
upper throat usually has a well-defined pure white 
patch. The bill characteristics (Figure 113) are the 
only ones for absolute identification. The bill of the 
American is of heavier and less slender build, and 
the nostrils are set near the centre of its length instead of well within its basal half (com- 
pare with Figure 114). These are distinctions that are evident only when both species 
are in hand for direct comparison. The feathering of the base of the bill gives an absolute 
distinction. In this species the feathering of the sides of the two mandibles extends 
forward an approximately equal distance (Figure 113), instead of the upper featheration 
decidedly over-reaching the lower. 
Field Marks. In adult male, lack of crest and reddish breast band, and considerably more 
white on sides, flanks, and wings. In flight, the large amount of white on the bend of the 
wing and outer scapulars. It is doubtful whether females may be known in life with cer- 
tainty from the Red-breasted Merganser. The darker brown of the head, its sharp ending 
on the neck, and the white throat are suggestive but not determinative characters. 
Nesting. In hollow trees or rock cavities near water. Nest of grasses, etc. 
Distribution. Common across the continent, nesting throughout western Canada, 
north to limit of trees. 
The American Merganser is the larger of the two representatives of 
this genus, but generally frequents the smaller waters, streams, and lakes. 
It is less common than the Red-breasted on the larger lakes or the sea. 
Otherwise the two birds are similar in habit. 
130. Red-breasted Merganser, saw-bill, fish-duck, sheldrake, shel- 
duck. Mergus senator. L, 22. Plate VI A. 
Distinctions. Male: similar to last species, but smaller and of lighter build through- 
out, with crest and reddish band across breast and with less white more interrupted 
with black on flank, wings, and neck. The delicate 
salmon tint of the underbody is present only in highest 
plumage and quickly fades to white in specimens. Female 
and young are alike and not distinguishable from parallel 
plumages of the American Merganser without careful 
study of details. The head is generally a paler red and 
blends gradually into the grey of the lower neck. The 
Figure 114 reddish colour suffuses over the throat which is usually 
Bill of Red-breasted Merganser; light, but it rarely has a decided white patch. The bill 
scale, 1. characteristics are the only ones for certain identification. 
The bill of the Red-breasted is of lighter and more slender 
build and the nostrils are well within its basal half. These are comparative distinctions, 
only evident when both species are in hand for direct comparison. The feathering of the 
base of the bill is absolutely distinctive. In this species the feathering of sides of the upper 
mandible extends well forward of that on the lower (Figure 114). 
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