THE BIRD BOOK 
Loon 
Black-throated Loon 
7. Loon. Gavia immer. 
Range. — North America north of the Mex- 
ican boundary, breeding from the northern 
parts of the United States northward. 
Unlike the Grebes, Loons do not build in 
colonies, generally not more than one, or 
at the most two pairs nesting on the same 
lake or pond; neither do they seek the 
marshy sloughs in which Grebes dwell, pre- 
ferring the more open, clear bodies of 
water. The common Loon may be known 
in summer by the entirely black head and 
neck with the complete ribbon of black and 
white stripes encircling the lower neck and 
the narrower one which crosses the throat. 
The back is spotted with white. In some 
sections Loons build no nest, simply scoop- 
ing a hollow out in the sand, while in other 
places they construct quite a large nest of 
sticks, moss and grasses. It is usually plac- 
ed but a few feet from the waters edge, so 
that at the least suspicion the bird can slide 
off its eggs into the water, where it can cope 
with any enemy. The nests are nearly al- 
ways concealed under the overhanging 
bushes that line the shore; the one shown 
in the full page illustration, however, was 
located upon the top of an old muskrat 
house. The two eggs which they lay are a 
very dark greenish brown in color, with 
black spots. Size 3.50 x 2.25. Data. — Lake 
Sunapee, N. H., June 28, 1895. Nest placed 
under the bushes at the waters edge. Made 
of rushes, weeds and grasses; a large struc- 
ture nearly three feet in diameter. Col- 
lector, H. A. Collins. 
8. Yellow-billed Loon. Gavia adamsi. 
Range. — Northwestern North America, along the Arctic and northern Alas- 
kan coasts. 
The Yellow-billed Loon with the exception of its whitish or yellowish bill 
in place of the black, is practically othenvise indistinguishable from the 
common Loon. It averages somewhat larger in size. This is one of the most 
northerly breeding birds and it is only within a very few years that anything 
has been learned about the breeding habits. Their nesting habits and eggs 
are precisely like the preceding except that the lattr average a little larger. 
Size 3.60 x 2.25. 
9. Black-throated Loon. Gavia arctica. 
Range. — From northern United States northward, breeding along the Arctic 
Coast. 
This species can be easily separated from the Loon by the gray crown and 
white streaks down the back of the neck. Its size, too, is about five inches 
shorter. The nesting habits are the same as the Loons and the eggs have 
rather more of an olive tint besides having the majority of spots at the 
larger end. Size 3.10x 2.00. 
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