THE BIRD BOOK
Loon
Black-throated Loon
7. LOON. Gavia immer.
Range.—North America north of the Mexican 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, preferring 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 scooping a hollow out in the sand, while in other places they construct quite a large nest of sticks, moss and grasses. It is usually placed 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 always 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 3.50x2.25. 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 structure nearly three feet in diameter. Collector, 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 otherwise 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 3.10 x 2.00.
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