The Pacific Loon 



grass, moss, roots, and floating stems. The external diameter of this 

 island citadel may be as much as three feet, and its depth one; but at 

 another time the bird is as likely to deposit her eggs on a sandbar with little 

 or no pretense at a nest. 



Young Loons "dive from the shell," and master water thoroughly 

 before they dream of flying. Soon after the chicks are brought off, the 

 parents separate for the rest of the season, the male retiring either to some 

 unfrequented lake or to the seacoast to undergo the summer moult. At 

 this season both birds cast their feathers, so thoroughly, indeed, as to be 

 for a time quite incapacitated for flight. When the young birds can use 

 their wings, they are taken to salt water, and lead thenceforth an idle life, 

 whose chief, or it may be sole, anxiety is the dodging of bullets. 



No. 418 



Pacific Loon 



A. O. U. No. 10. Gavia arctica pacifica (Lawrence). 



Synonyms. — Pacific Diver. Western Loon. Lawrence's Black-throated 

 Diver. 



Description. — Adult in summer: (Somewhat similar to preceding species, but 

 top of head and nape light bluish gray) ; chin and throat black with violet and purplish 

 reflections, shading on side of neck through black-and-white-streaked area into dull 

 smoke-gray on crown and light ashy on hind-neck, the streaked patches connected 

 across throat anteriorly by a necklace of short white streaks in sharp relief; underparts 

 white, the sides like back but scarcely spotted, the anal dusky band narrowing centrally; 

 under tail-coverts wholly black or else white-tipped; upperparts black with purplish 

 reflections; feathers of scapulars and interscapulars each with subterminal squarish 

 spot of white, thus forming four patches of transverse white rows; wing-coverts speckled 

 with smaller oval spots of white; sides of cervix sharply black-and-white-streaked, 

 as in G. immer. Bill black, relatively smaller than in immer; feet and legs black exter- 

 nally, yellowish dusky internally; eyes red. Adult in winter and immature: Corre- 

 sponding closely with similar stages of G. immer — crown and nape lighter. Length 

 (av. of 10 Monterey specimens): 584.2 (23.00); wing 297.2 (11.72); bill 55 (2.17); 

 tarsus 75 (2.95). 



Recognition Marks. — Brant size; like G. immer, but smaller; top of head and 

 nape in summer plumage bluish gray; without white speckling on back, as distinguished 

 from Gavia stellata; not to be distinguished out of hand even in breeding plumage from 

 Gavia arctica, which is larger. 



Nesting. — Does not breed in California. Nest and eggs much as in preceding 

 species, but egg narrower, sometimes cylindrical ovate and averaging darker, even to 

 "mummy brown." Av. size 75.5 x 47 [2.97 x 1.85] (Bent). Index 62.2. Season: 

 June 8-July 23. 



Range of Gavia arctica. — Northern part of Northern Hemisphere, south in winter 

 to the Mediterranean, the Caspian Sea and Japan. In America as follows: 



2034 



