314 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



flecks of pale browns, or shades of olive, gray, or drab. Sometimes the 

 spots are more concentrated about the larger end, and sometimes the 

 smaller end is almost unmarked. 



The measurements of 50 eggs average 32.4 by 23.4 millimeters ; the 

 eggs showing the four extremes measure 35.0 by 23.4, 34.5 by 25.2, 

 29.2 by 23.2, and 33.5 by 21.6 millimeters. 



Young. — Both sexes assist in the duties of incubation and care of the 

 young. Bendire (1895) gives the period of incubation, "as nearly as I 

 can judge, about sixteen or seventeen days." This agrees closely with 

 the reported period for the European bird, 17 to 18 days. But M. P. 

 Skinner (1916) says that in Yellowstone Park the eggs "are laid between 

 February 28 and March 3, and the brooding commences immediately. 

 At such a time the brooding bird is subjected to all the vagaries of truly 

 wintry weather." "Often," he says, "she sits through raging snowstorms 

 protected only by the tuft of cedar needles over the nest, and many 

 times has the writer seen the bird actually on the nest with the ther- 

 mometer below zero. Under such conditions she draws herself down 

 with only her tail feathers and perhaps her bill showing above the rim 

 of the nest. She is very fearless, even submitting to capture rather 

 than leave the nest ; when she leaves, she does so quietly, and returns 

 immediately after the intruder is gone. After brooding twenty-two days 

 the young are hatched, naked of course, and with their eyes closed. Four 

 weeks later the young leave the nest and by May 5 are fully feathered 

 and shifting for themselves. Notwithstanding this early start there is 

 no evidence to show that a second brood is raised." 



The longer period of incubation and the longer altricial period, as 

 given by Mr. Skinner above, was probably exceptional or due to too 

 much exposure to wintry weather. For Major Bendire (1895) says 

 that the young remain in the nest only about eighteen days ; and Mr. 

 Bradbury (1917b) showed the altricial period to be about three weeks. 



Mrs. Wheelock (1904) says that the young "were fed on piiion nuts, 

 which were carried to the nest and hulled by the adult while perched 

 just outside on the branch. I could not discover that any other food 

 was brought them. At first this was given by regurgitation, but when 

 the young were a few days old the food was supplied to them direct. 

 As soon as they were ready to leave the nest they were coaxed by short 

 flights to the nut pines, and readily learned to shell the nuts and provide 

 for themselves. Then it would seem a complete change of diet was 

 necessary; for they disappeared from these regions entirely, flocking to 

 a locality where berries, fish, and insects abound. By the middle of 

 June not one was left in the old breeding grounds." 



Apparently the young are also fed by regurgitation after they have 



