634 THE LOON. 



"During the day 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. 



A. O. U. No. 7. Qavia 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 purpHsh reflections; bill black; feet and legs black 

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

 Above dark 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 ; 

 feet brownish dusky externally, yellowish internally. Length 28.00-36.00 (71 1.2- 

 914.4) ; wing 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. Av. size, 3.50 x 2.25 (88.9 x 57.2). 



