360 BULLETIN 19 5, UNITED STATES NATIONAL MUSEUM 



11 days. Two of the nests had young with a nestling period of 13 

 days. Both of these nests were early. The nestling period for one 

 nest was 12 days, for four, 11 daj^s, for four, 10 days, and for one, 9 

 days." 



He noted that both parents helped to feed the young in the nests. 

 A total of 8 hours 6 minutes on parts of five days was spent in obser- 

 vation of the feeding process at two nests. He says : 



During this period, the different females made a total of 40 trips to the nest 

 with food, and the males, 31 trips. This food consisted almost entirely of white 

 grubs, soft caterpillars, and earth worms. A small part of the time was spent 

 in brooding, this duty being shared both by male and female. Most of the 

 periods of brooding occurred in the early morning when the weather was cool 

 and the young still were without a full coating of feathers. On one occasion the 

 female, being unable to cover the five young, used her bill to pull them towkrd 

 her. Both male and female always inspected the nest for excreta before going 

 on to brood. Excretion always occurred immediately after the nestling, or 

 nestlings, were fed. The excreta was encased in a transparent bag, which pre- 

 vented it from soiling the nest while being removed. The excreta from the 

 very young birds was almost always eaten, while that from the older nestlings 

 was usually carried away and dropped. * * * 



In cases where a second nest was built after young were successfully brought 

 off the preceding nest, the female remained to help care for the young only a 

 few days, after which she built the second nest without assistance of the male, 

 his duty being to care for the nestlings. There were only two nests in which 

 this occurred during the year. The other nestlings were brought off too late, due 

 to previous failures, for the adults to build another nest. In two instances 

 where the female did not build another nest after the young were brought olf, 

 the young were divided, the male taking a part of the young, and the female 

 the remainder. Also in these two instances, the territory was also divided. 

 * * * After the first brood of young became independent, it seemed that 

 the male returned to assist the female in the care of the second brood. 



Dr. Ira N. Gabrielson (1912) made a careful study of a brood of 

 young brown thrashers in Iowa; the nest was on the ground, which 

 he remarked was unusual ; when it was discovered, on June 17, it held 

 four young, "not more than 24 hours old," and an addled egg ; a blind 

 was set up near the nest and observations began on June 23 and con- 

 tinued until the young left the nest on June 28. He says : 



[On June 23] the afternoon was hot and sultry and the nest was in such a 

 position as to be exposed to the hot rays of the sun. One or the other of the 

 old birds bi'ooded almost all of the time. During the afternoon, the male 

 brooded once for a period of 26 minutes and the female for 20 minutes, but the 

 periods as a rule were short, being from 2 to 5 minutes in length. At about 

 2 o'clock the shadow of an oak tree was thrown on the nest and the old birds 

 ceased brooding. * * * There was a marked difference in the position as- 

 sumed by the male and female in brooding. The male sat on the edge of the 

 nest with his feathers ruffled up, or stood in the nest in much the same posture, 

 affording very poor protection for the young as compared with that given by 

 tbe female. She spread her wings, ruffled her feathers, and stood in such a 

 position as to completely shade the nest. 



