EASTERN MOURNING DOVE 407 



was full of pine needles and soft rubbish, such as squirrels use. 

 It was quite a large nest, measuring 25 by 15 inches. The doves had 

 scraped out a hollow in the pine needles and laid one egg. I visited 

 the nest a^ ain on April 28, when the dove flew off, as before, and the 

 nest held two eggs. I photographed the nest and collected the eggs. 

 As a pair of great-horned owls and a pair of Cooper's hawks were 

 nesting in these woods, the doves stood a poor chance of raising a 

 brood, or even escaping with their own lives. 



Eggs. — The mourning dove lays almost always two eggs, but there 

 are a few records of three, or even four. In shape they vary from 

 elliptical oval, the commonest shape, to elliptical ovate or ovate. The 

 shell is smooth with very little gloss. The color is pure white. The 

 measurements of 47 eggs average 28.4 by 21.5 millimeters; the eggs 

 showing the four extremes measure 31 by 22, 29.5 by 23, 26 by 20.5, 

 and 28.5 by 20 millimeters.] 



Young. — The young of the mourning dove are helpless when 

 hatched, and during the two weeks they remain in the nest the} r 

 require constant care from their parents. They are fed by regurgi- 

 tation during most of their nest life, but solid food, such as insects 

 and seeds, is gradually substituted, and at the time of leaving the 

 nest it largely replaces the pigeon milk." The contents of the crop 

 of a young bird, examined at the end of its nest life, consisted almost 

 entirely of seeds (principally grass seeds) and less than 2 per cent 

 "pigeon milk." [See Townsend (1906).] 



Gabrielson (1922), who studied the nest life from a blind, clearly 

 describes the process of regurgitation thus : 



At 7.30 a. in. a squab backed toward the blind and getting from beneath the 

 parent raised its head and mutely begged for food. The adult (presumably 

 the female) responded immediately by opening her beak and allowing the nest- 

 ling to thrust its beak into one corner of her mouth. She then shut her beak 

 on that of the nestling and after remaining motionless for a short time began 

 a slow pumping motion of the head. The muscles of her throat could be seen 

 to twitch violently at intervals, continuing about a minute, when the nestling 

 withdrew its beak. The other nestling then inserted its beak and the process 

 was repeated, 15 seconds elapsing before its beak was removed. With inter- 

 vals varying from 5 to 10 seconds (watch in hand) four such feedings, two to 

 each nestling, occurred. The nestling not being fed was continually trying 

 to insert its beak in that of the parent and at the fifth feeding both succeeded 

 in accomplishing this at the same time. The nestlings' beaks were inserted from 

 opposite sides of the parent's mouth and remained in place during the feeding 

 operation although I could not say whether or not both received food. While 

 being fed the nestlings frequently jerked the head from side to side and also 

 followed the motion of the parent's beak by raising and lowering themselves by 

 the use of the legs. They were not more than five days old but had better use 

 of their muscles than the young of passerine birds at from eight to ten days of 

 age. The entire process described above occupied about six minutes, after 

 which the nestlings crawled back beneath the parent. 



