176 NESTS AND EGGS OF NORTH AMERICAN BIRDS. 



the process of incubation is the fact that the eggs are concealed with a 

 covering of weeds and other vegetable material during the day "and 

 they are uncovered at dusk by the bird, who incubates them until the 

 morning sun relieves her of her task." 



Hab. British Provinces southward to Brazil, Buenos Ayres, and Chili, including the West Indies and 

 the Bermudas, breeding nearly throughout its range. 



736. Loon — colymbus torquatus. Olivaceous-brown, sometimes 

 olivaceous-drab, spotted and blotched with very dark brown, narrowly- 

 oval, occasionally very much lengthened; normally two in number, some- 

 times three; size from 3.40 to 3.90 long by 2.10 to 2.38 broad. The 

 Great Northern Diver breeds from the northern tier of States north- 

 ward. The Loons are noted for their powers of diving, disappearing 

 beneath the surface of the water at the flash of a gun. They are large, 

 heavy birds with flattened bodies and rather long neck; the legs are placed 

 very far back in the body. They are abundant along the coasts and large 

 inland waters. The voice of the Loon is a loud, long-drawn, harsh cry. In 

 winter this species is generally dispersed in the United States. Nests in 

 the neighborhood of large inland lakes and ponds, on some low island or in 

 meadows, where the bird collects a large pile of grasses, sods and weeds 

 in which it forms a hollow about sixteen inches in diameter and four or 

 five deep. 



Hab. Northern part of Northern Hemisphere. In North America breeds from the northern States 

 northward; ranges in winter south to the Gulf States 



738. Black-throated Diver — colymbus arcticus. Dark greenish- 

 brown, spotted and blotched with very dark brown, oval to elliptical in 

 shape; size from 2.90 to 3, in length by 1.90 to 2. broad. In the breed- 

 ing season this species is distributed throughout the Arctic regions. Nest- 

 ing like the last. General habits the same. 



Hab. Northern part of the Northern Hemisphere. In North America migrating south in winter to the 

 Northern States. 



739. Pacific Diver — colymbus pacificus. This Loon is abundant on 

 the Pacific coast. Its eggs are like those of the Black-throated Loon, but 

 average smaller. Its general habits are the same. 



Hab. Pacific coast of North America, south in winter to Cape St. Lucas and Guadalupe Island. 



740. Red-throated Diver — colymbus septentrionalis. Olivaceous 

 or greenish-brown, blotched and spotted with very dark brown, exactly 

 resembling those of the Loon in form, color and markings, but are smaller. 

 The Red-throated Loon breeds in the Arctic regions from Labrador north- 

 ward, and begins to lay early in June. The nesting habits are similar to 

 those of the other species. 



Hab. Northern part of Northern Hemisphere, migrating southward in winter nearly across the United 

 States. 



