68 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



jay would ascend by the usual vertical hopping and short flights to the nest. 

 Following the taking of black oak twigs the two jays, together, flew across the river 

 which flowed close by the nest tree, and there, descending quickly to the ground, 

 sought material in an azalea thicket at the edge of the water. Each took a 

 quantity of twigs and grass and apprently also some mud, and flew again to 

 the nest tree. Again they took twigs from the black oak. 



They say of a nest examined in the Yosemite region : 



It was solid in construction, with a large external basal framework of dead 

 and more or less weathered twigs of irregular shape and small diameter (2 milli- 

 meters or less). Many of these were black oak twigs while others were of a 

 very furry herbaceous plant. All of the material of this outer framework, as 

 was attested by the clean, fresh-appearing ends of the pieces, had been freshly 

 broken off by the jays. This suggests that, save for the small amount of 

 herbaceous material, all the outer constituents were gathered above the ground. 

 The outside framework measured about 300 millimeters (12 inches) in one 

 direction and 400 millimeters (16 inches) in the other. 



The inner cup of this nest was composed of dry needles of the yellow pine, 

 held together by enough mud to give the structure a firm resistant feel. The 

 mud, however, did not extend to the inner surface. The interior of the cup 

 consisted solely of pine needles, which crossed and recrossed so as to make a 

 porous interior lining. This cup was 100 millimeters (4 inches) in diameter 

 at the rim and 68 millimeters (25^ inches) deep at the center. 



Eggs. — The blue-fronted jay lays three to five eggs, usually three 

 or four; Mr. Rowley, who has examined a number of nests, tells me 

 that sets of four are found as frequently as three but that he has found 

 only one set of five. The eggs are usually indistinguisliable from eggs 

 of Steller's jay, but RoUo H. Beck (1895) describes some variations, as 

 follows: "In a series of these eggs now before me there is considerable 

 variation in shape and markings. One set closely resembles those of 

 the California Thrasher, another is marked exactly like the eggs of the 

 Yellow-billed Magpie, and others the eggs of the California Jay. Some 

 have but few spots, principally about the larger ends, while others have 

 the ground color nearly obscured, so thickly are they spotted. The 

 usual ground color is light-blue, which is spotted with various shades 

 of brown and not infrequently with lavender and purple." 



The measurements of 52 eggs in the United States National Museum 

 average 30.22 by 22.61 millimeters ; the eggs showing the four extremes 

 measure 34.0 by 24.0, 27.6 by 23.2, and 29.5 by 21.2 millimeters. 



Young. — Bendire (1895) says that "an tgg is deposited daily, and 

 incubation lasts about sixteen days. The male assists in these duties, 

 and usually but one brood is raised in a season." Grinnell and Storer 

 (1924) say: "During the nesting season the jays are to be seen in 

 devoted pairs, and after the broods leave the nest the full-grown young 

 and their parents remain for a time in family parties. With the coming 



