BIRDS OF NEW YORK 99 



and air sacs. They make their nests on the ground near the water's edge, 

 and the eggs are two, of an elongated oval, olive or brown in color with 

 spots of brown and blackish. The young are covered with a sooty grayish 

 down, changing to white on the belly. They swim about as soon as hatched. 

 The family consists of only five species, all confined to the holarctic realm. 



Gavia immer (Briinnich) 

 Common Loon 



Plate a 



Colymbus immer Brunnich. Ornithologia Borealis. 1764. p. 38 

 Colymbus glacialis DeKay. Zool. N. Y. 1844. pt 2, p. 285, fig. 299 

 Urinator imber A. O. U. Check List. Ed. 2. 1895. No. 7 



ga'via from the Italian name of a gull, first applied to loons by Forster in 



1788; immer from the Swedish immer and English ember, or imm^r, 



used in composition with goose for this bird, Ember goose 



Description. Summer plumage: Head and neck rich greenish black, 

 with purplish reflections; small patch of shining white streaks on throat, and 

 a larger one on each side of neck, consisting of raised edges of the feathers 

 so that the streaks may be felt as well as seen; upper parts black, with a 

 pair of white spots on each feather, those on the back and sca])ulars being 

 square, or rectangular, the others oval; under parts pure white; sides of 

 upper breast sharply streaked with black; a dusky band across the belly; 

 bill black, sometimes tipped with yellowish; iris red; feet blackish. Winter 

 and immature: Upper parts dusky brown, the feathers edged with grayish; 

 crown and back of neck blackish ; sides of head and neck white mixed with 

 grayish; under parts white. 



Length 31-36 inches; extent 52; wing 12. 5-14. 25; culmen 2.75-3; 

 gape 4-4.25; hight of bill at nostrils .75-85; tarsus 3-3.5; middle toe and 

 claw 4.25-5. Females and young have the smaller dimensions, the bill of 

 young especially, being considerably smaller than that of adult. 



Distinctive marks. As shown by plate 2, the Common loon may 

 easily be distinguished in breeding plumage from the Red-throated and 

 Black-throated loons by the marked difference in coloration of its head 

 and neck. In winter plumage, the feathers of its upper parts are margined 

 with grayish, while those of the Red-throated loon are spotted with white, 

 and the Black-throated loon is decidedly smaller. The bills of the Black- 

 throated and Common loons are very similar in shape, but that of the 



