400 LIFE HISTOEIES OF NORTH AMERICAN BIRDS. 



from ovate to elongate and cylindrical ovate ; the ground color is usually a pale 

 pea green, less often a drab or greenish olive. They are usually profusely 

 blotched and spotted with different shades of brown, lavender, and drab. In a 

 number of specimens the markings are evenly distributed over the entire egg, 

 in a few cases nearly hiding the ground color; in others they predominate at 

 one of the ends, and an occasional egg is but slightly marked, showing the 

 ground color clearly. One such light-colored egg is often found in sets other- 

 wise heavily marked. The shell is strong and compact and shows little or no 

 gloss. The markings in very rare instances approach the peculiar elongated 

 style so characteristic of the eggs of the White-necked Raven. 



The average measurement of fifty-four eggs in the United States National 

 Museum collection, all but two taken by myself, is 49.53 by 32.76 millimetres, 

 or 1.95 by 1.29 inches. The largest egg of the series measures 60.45 by 37.84 

 millimetres, or 2.38 by 1.49 inches; the smallest, 41.15 by 31.50 millimetres, or 

 1.62 by 1.24 inches. 



The type specimens, Nos. 20321 and 20325 (PI. 4, Figs. 1 and 2), both from 

 the Bendire collection, were taken by the writer near Camp Harney, Oregon, on 

 April 22, 1876, and April 26, 1877, respectively, the first from a set of seven 

 eggs, the last from a set of six, and these represent the two principal styles of 

 coloration. 



160. Corvus corax principalis Ridgway. 



NORTHERN RAVEN. 



Corvus corax principalis Ridgwat, Manual North American Birds, 1887, 361. 

 (B 423, part; O 226, part; R 280, part; O 338, part; U 486a.) 



Geographical range: Northern North America ; from Greenland west to Alaska; 

 south to British Columbia, northern Canada, aud Labrador. 



The Northern Raven is admitted to subspecific rank in our avifauna mainly 

 on the claim of having a relatively larger or stouter bill and a shorter and stouter 

 tarsus than the southern bird, with more of the upper portions of the tarsus 

 concealed by the feathering of the lower parts of the thighs, the plumage gen- 

 erally being less lustrous. Ravens are well known to attain a great age, and 

 instances are on record of these birds having lived over a hundred years; 

 variations in plumage may therefore depend to some extent on age. These 

 differences may possibly prove constant in the far north, to which for the present 

 I prefer to restrict its range. 



Its general habits and call notes resemble those of the American Raven; 

 like it, it lives to a great extent on offal and refuse of any kind, and is generally 

 most abundant in the immediate vicinity of Indian camps and settlements, which 

 are mostly located on the seashore, or on the banks of the larger rivers in the 

 interior, where these birds act as scavengers. This is especially the case on 

 the Alaskan Peninsula and on the mainland, where hundreds of these birds may 



