Range.--Northwestern North America, along the Arctic and northern Alaskan 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 latter average a little larger. Size 3.60 × 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 × 2.00.
[Illustration 020: Loon. Black-throated Loon.] [Illustration: left-hand margin.]
Range.--Western North America along the coast chiefly, breeding from Alaska south to British Columbia. In winter, south along the coast to Mexico.
This species differs from the Black-throated only in the tint of the head reflections. The habits are the same as those of the other members of the family. They lay two eggs of a greenish brown or greenish gray hue with black spots. Size 3.10 × 1.90. Data.--Yukon River, Alaska, June 28, 1902. Nest of rubbish on an island; found by a miner.
Range.--Northern parts of North America, breeding from southern Canada northward in the interior on both coasts. South to the middle portions of the United States in winter.
This is the smallest of the Loon family, being twenty-five inches in length. In plumage it is wholly unlike any of the other members at all seasons of the year. In summer the back, head and neck are gray, the latter being striped with white. A large chestnut patch adorns the front of the lower part of the neck. In winter the back is spotted with white, whereas all the others are unspotted at this period. The nesting habits are identical with the other species; the ground color of the two eggs is also the same. Size 2.00 × 1.75.