634 THE LOON. 



"I hiring the da) we invariably found the eggs concealed by a covering of 

 muck, as above described, but, as we ascertained by repeated visits at night 

 and in the early morning, they are uncovered at dusk by the bird, who incu- 

 bates them until the morning sun relieves her of her task." 



The eggs are probably covered thus only when there is danger of their be- 

 ing discovered by predatory Gulls and the like, as I have found them in 

 certain Illinois swamps, where no such danger existed, quite exposed. 



The hardiness of the unhatched chick may be inferred from the preced- 

 ing account. I once took a set of four eggs so incrusted with filth that not even 

 soap and water and a bristle-brush would restore the original color. Finding 

 time two days later to remove their contents, I was somewhat disconcerted 

 when the disimprisoned young ones cheeped lustily, forty hours from the nest. 



No. 317- 



LOON. 



V 1 ). [J, N 0i -. Gavia imber (Gunn.). 



Synonym. — Great Northern Diver. 



Description. — Adult in summer: Head and neck black with metallic re- 

 flections, most intense on lower neck ; middle of the throat crossed by a narrow bar 

 of white streaks; a similar but wider bar on each side of neck lower down; 

 under-parts pure white; upper parts greenish black, sharply spotted with white 

 In regular transverse rows, — the spots mostly squarish, smallest on the upper 

 back and rump, largest on lower scapulars; the sides black, similarly ornamented 

 with rounded spots ; sides of cervix black and white, streaked or striped ; wing- 

 quills blackish, with warm purplish reflections; bill black; feet and legs black 

 externally, yellow internally; iris carmine. Adult in winter and immature: 

 \l>..\e .lark brown, clear and greenish glossed on crown and back of neck, feath- 

 ers of the back, etc., more or less heavily tipped with ashy gray or dull buffy ; 

 entire under-parts, including sides, white, shading on sides of head or alternating 

 with brown of upper parts in large dentations; bill light blue with dusky ridge; 

 Feel brownish dusky externally, yellowish internally. Length 28.00-36.00 (711. 2- 

 9144); "ing 14.00 (355.6); tail 2.60 (66.); bill 3.00 (76.2); along gape 4.00 

 (101.6); tarsus 3.40 (86.4). 



Recognition Marks. — Brant to Eagle size; back black speckled with white; 

 head and neck black interrupted by white-streaked spaces; below white; large. 

 pointed bill. Large size distinctive as compared with other divers. 



Nest, a mere depression in sand or gravel, etc.. near the edge of lake or pond. 

 Eggs, 2, dark brown or olive-brown, faintly and sparingly spotted with darker 

 or blackish. \v. size, 3.50 x 2.25 (88.9 \ 57.2). 



