218 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



insects and small reptiles, which probably furnish the larger portion 

 of the food of these birds, are much more abundant in southern Arizona 

 after the rainy season commences, about the last of May, than before, 

 and these birds seemingly understand this and act accordingly." 



Shaler E. Aldous (1942), in his report on this raven, says: "Activity 

 around old nests begins in April, and sometimes the ravens stay con- 

 stantly in the vicinity of chosen nests as if maintaining claim to them." 



Eggs. — The white-necked raven lays three to seven eggs, rarely eight, 

 but the commonest numbers are five, six, or seven. I cannot improve 

 on Major Bendire's (1895) fine description of them, which is based on 

 a series of 288 eggs in the United States National Museum, so I shall 

 quote it here: 



The eggs of the White-necked Raven are, in nearly every instance, readily 

 distinguishable from those of the other species of the Corvina-e found in North 

 America, and this is due to the characteristic style of their markings. The 

 ground color varies from pale green to grayish green, and only very rarely to a 

 light bluish green. Two distinct types of markings are fotmd among these eggs, 

 the principal but usually not the most notable one consisting of a mass of 

 longitudinal streaks and blotches of different shades of lilac, lavender grey, and 

 drab, nmning from pole to pole of the egg, and these are again more or less 

 hidden and partly obliterated by heavier and more regularly defined spots and 

 blotches of different shades of brown. In not a few sets these lighter and more 

 subdued shades are wanting, and are replaced by a more conspicuous brown; 

 but almost all of the eggs show the peculiar longitudinal streaks and hair lines 

 so prominently characteristic of the eggs of the genus Myiarchus. Besides the more 

 regularly shaped markings common to the balance of the eggs of our Corvinae, 

 they are on an average also decidedly lighter colored, and a few eggs are almost 

 unspotted. Scarcely any two sets are exactly alike. The shell is strong and 

 compact. In shape they are mostly ovate; a few are elliptical and elongate ovate. 



The measurements of 288 eggs in the United States National Museum 

 average 44.20 by 30.22 millimeters; the eggs showing the four extremes 

 measure 48.8 by 33.8 and 38.1 by 27.9 millimeters. 



Young. — According to Bendire (1895), "only one brood is raised 

 in a season. Both sexes assist in incubation, which lasts about twenty- 

 one days ; this usually begins only after the set is completed ; but young 

 birds varying in size are sometimes found in the same nest." Young birds 

 apparently remain in the nest about a month, though I have no definite 

 information on this; they probably hatch late in June or early in July, 

 and young birds of various ages have been found in the nests all through 

 July. "Early in August the young birds begin leaving the nests, and 

 when they have attained their growth young and old gather together 

 in enormous flocks" (Swarth, 1904). 



Phimnges. — Nestlings are like other young ravens or crows, naked 

 at first but soon scantily covered with brownish-gray down. They are 



