LAWRENCE'S GOLDFINCH 491 



The measurements of 50 eggs average 15.4 by 11.6 millimeters; the 

 eggs showing the four extremes measm-e 17.3 by 12,0, 16.5 by 12.5, 

 14.2 by 11.2, and 14.7 by 10.7 millimeters. 



Incubation. — The incubating female goldfinch remains on the 

 nest almost continuously except for short intervals when the male 

 waits for her to leave after a feeding. At one nest in early stages of 

 incubation, the female remamed on the nest almost continuously and 

 there was little variety in her activity. On seven days up to June 11, 

 an observer spent 56 hours at this nest. Altogether the female was 

 off the nest only 27 times for a total of 110 minutes or only 3.3 percent 

 of the time. Of the 27 trips off the nest, 10 were for one minute or 

 less, 7 for two minutes, 1 for three minutes, 2 for five minutes, 3 for 

 six minutes, 1 each for seven, nine, thirteen, and thirty-three minutes. 

 She made 16 of these trips before 7:15 a,m., 2 between 9:00 and 10:00 

 a.m., 3 between 11:00 a.m. and noon, and 6 between 2:00 and 6:00 

 p.m. In the same period the male made 57 trips to the nest, an 

 average of 1 per hour. 



Young. — Feeding of the young in the nest is at fairly uniform hourly 

 intervals. This may be r^ulated by the time required to gather and 

 prepare the food, and it may also be influenced by the hunger limits 

 of the bird to be fed. Through the 11 days before two young left 

 the nest on July 14, in 109 hours we recorded 139 feedings by a parent 

 bird. The male fed the female 19 times, 6 times on the fu'st day, 7 on 

 the second, 4 on the third, 1 on the fourth, and 1 on the eleventh day. 

 This shows the time required to change from the feeding pattern 

 during incubation when the male delivers all food he brings to the 

 nest to the female and she eats it. The first few days after hatching 

 the tendency is for the female to take the food and deliver it to the 

 young after the male leaves, and he has great difficulty reaching past 

 the begging female to get food to the young. When the female no 

 longer has to brood the young, she accompanies the male on trips 

 for food. Both parents then tend to arrive at the nest together and 

 to take turns in feeding the young. The male nearly always feeds 

 first at the start, but later the female delivers food first almost as 

 often as the male does. 



Adults continue to feed the young intermittently for some time after 

 they leave the nest. A post-nesting flock of nearly 50 Lawrence's 

 goldfinches, both adults and young, foraged along the edge of an aban- 

 doned field on the Reservation one early afternoon at the end of June. 

 The flock kept in one small area where they fed mostly on the ground, 

 picking up the ripened seeds then available from many annual plants. 

 There was much flying about, and the food calls of the young were the 

 most conspicuous sounds in the vicinity. The young birds, which 

 appeared to outnumber the adults, seemed to feed themselves part of 



