AMERICAN RAVEN 207 



or less, 35 percent six eggs, 30 percent seven eggs, and 5 percent eight 

 eggs. 



The eggs vary in shape from ovate to elongate-ovate, or rarely 

 cylindrical-ovate. They are merely large editions of crows' eggs and 

 not so muc.h larger as one might expect; some of the smallest ravens' 

 eggs are not much larger than large crows' eggs. The colors and 

 markings of ravens' eggs have nearly all the variation shown in crows" 

 eggs, though I have never seen the darkest types of crows' eggs quite 

 matched. The ground color varies from "glaucous," through various 

 shades of "greenish glaucous," to "pea green"; Bendire (1895) adds 

 greenish olive and drab to the list of variations. The markings, in 

 shades of dull, dark browns, drab and olive, show considerable varia- 

 tion in pattern; some eggs are sparingly marked with small spots, and 

 some are profusely covered with small spots and fine dots ; others are 

 unevenly marked with irregular blotches and scrawls. 



The measurements of 54 eggs in the United States National Museum 

 average 49.53 by 32.76 millimeters; the eggs showing the four extremes 

 measure 60.5 by 37.6, 51.8 by 48.3, 40.9 by 31.6, and 48.3 by 30.5 

 millimeters. 



Imtihation. — Major Bendire (1895) writes: "Only one brood is 

 raised in a season. Incubation lasts about three weeks, commencing when 

 the set is completed, and I believe both sexes assist in this labor. When 

 the female is sitting on the nest the male may frequently be seen perched 

 on some small bush or a dead branch of a tree on the opposite side of 

 the canyon from where the nest is situated, uttering an occasional 'klunk- 

 klunk' and keeping a sharp lookout. Should anyone approach in that 

 direction, though some distance off, he will warn his mate, uttering a low 

 alarm note while flying past the nest, when she will usually slip oft' and 

 try to keep out of sight, while he endeavors to draw attention to himself, 

 acting at the same time as utterly unconcerned as if he had no interest 

 whatever in that particular locality." 



Young. — The young are well cared for, fed, and guarded by both 

 parents. When the birds are four weeks or a month old their wings 

 are sufficiently developed for flight and they are ready to leave the 

 nest. Attended by their parents for some time after that, they are 

 taught to forage for themselves. Soon after they have learned how 

 to hunt for their food they all disappear from the vicinity of their nest- 

 ing site and resort to the valleys where food is more easily obtained. 

 After a few weeks the family party breaks up, and the young, now able 

 to shift for themselves, are deserted by their parents. 



Plumages. — The plumages and molts are the same as in the northern 

 raven, to the account of which the reader is referred. 



