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 3.50 × 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 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 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.] Page 19 10. PACIFIC LOON. _Gavia pacifica._ 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.