170 U.S. NATIONAL MUSEUM BULLETIN 23 7 pabt i 



by this important event. The female becomes extremely fidgety 

 and excitable, yet very daring. She readily hazards many dangers 

 she would not have faced before her parental instincts were quickened 

 by the appearance of her young. Without the least hesitancy she 

 will return to her nestlings while an observer stands in full view only 

 a few yards away. When this mother bird returned for the first 

 time after the young hatched she uttered a series of low subdued 

 notes. She then carried the egg shells away and dropped them far 

 from the nest. This habit, held in common with many other birds, 

 is a regular part of the dickcissel's housekeeping. All refuse and 

 filth from the young birds is also immediately disposed of or carried 

 away, so that the nest and its surroundings always present a neat 

 and clean appearance. 



The first food, a larva, was delivered to the young about 30 minutes 

 after it emerged from the egg. The larva was crushed into small 

 pieces which were thrust, at intervals of several seconds, into the 

 nestling's gaping mouth. Meanwhile the male sat on top of his 

 favorite telephone pole and poured forth a volume of song, seemingly 

 oblivious to what was happening in the weeds and grass below him. 

 The following day two more eggs hatched, but the fourth egg was 

 sterile and remained in the nest unbroken until after the fledglings 

 left, 9 days later. 



During the first 3 days the female brooded her young very closely 

 and left the nest only to obtain food. Even during the heat of the 

 day when the mercury rose above 90°F. she clung closely to the 

 nest. When the heat became excessive she panted incessantly and 

 her partially spread wings protruded over the edge of the nest. She 

 remained faithful to her family thi-ough the hottest weather, while 

 the male did nothing but encourage her with his song. On the 

 fourth and fifth days she spent less time on the nest, and from the 

 sixth to the ninth days, when the ever-increasing appetites of her 

 young demanded more and more food, she seldom lingered at the 

 nest any length of time. After the sixth and seventh days the sprout- 

 ing feathers and the contact of the young birds' bodies with one 

 another easily retained the high body temperature without the aid 

 of the parent. The temperature of nestlings 6 days old which had 

 been left alone in the nest for an hour was 106°F., normal for birds, 

 while the smTOunding temperature was only 80 °F. 



The male dickcissel attends strictly to his own affairs and seldom 

 meddles with the fife of other birds nearby. When strangers intrude 

 on his premises he not only leaves them alone, but often exhibits a 

 marked timidity. One day a young kingbird alighted on the fence 

 wire just above the dickcissel's nest. It was followed by its parent, 

 which continued to feed the fledgling there for more than 20 minutes. 



