CHESTNUT-COLLARED LONGSPUR 1643 



The young may hatch over a period of a day or two. As Harris 

 (1944) describes the process: 



"In one observed case, hatching of one egg required over half a day, 

 but in the majority of cases it seemed to take a shorter time. An 

 irregular series of perforations is made by the young bird around the 

 circumference of the shell about mid-way down the main axis. When 

 the cut is completed, and the young bird has finally extricated itself, 

 the two halves of the shell are carried away by the parent; pieces of 

 shell have been found as far as a hundred feet away from the nest." 



Young. — Both parents feed the young and tend to nest sanitation. 

 The fecal sacs may be either eaten or carried away and dropped at a 

 distance. For the first few days the female broods the young up to 

 50 percent of the daylight hours, and the male makes most of the 

 trips with food. Daytime brooding, which is exclusively by the 

 female, ends about the fifth day, except during cold and rainy periods 

 and thereafter the female makes more trips with food than the male. 

 At one nest the young were fed 7.2 times per hour (5-hour watch) 

 when 3 days old, and 16 times per hour (9-hour watch) when 9 days 

 old. Watches at two nests of 8- or 9-day-old young on June 13 and 

 June 23 showed the daily feeding period to last 17 hours. 



The parents feed the young whatever insect food is available. 

 Harris (1944) found his birds feeding their young almost exclusively 

 on grasshoppers, but this was at a time when they were very abundant. 

 At our study area the most common food seemed to be small green 

 caterpillars and small brown segmented worms. The parents subdued 

 these by biting them and beating them on the ground before giving 

 them to the nestlings. 



The following account of development is based on daily observations 

 at four nests of individually color-marked young: 



First day: The newly hatched young are very weak. They have 

 just strength enough to gape for food as they lie in the nest. They 

 appear well covered with down on the head and back after the down 

 dries. They weigh about 1.6 grams at hatching, and gain 0.6 to 

 0.7 grams the first day. (Moriarty, (1944) reports four young 

 weighed a total of 5.48 grams, or 1.37 grams each at hatching.) 



Second day: The young are much stronger and gape for food at 

 any noise made near the nest. They now weigh between 2.0 and 

 2.5 grams and will gain about 1.4 grams during the day. 



Third day: The young are growing rapidly and the down is now 

 about half an inch long. They will gain about 1.8 grams daily from 

 the 3rd through the 8th day. 



Fourth day: The eyes of the more developed young are open a 

 slit. The feather sheaths are beginning to protrude from the skin. 

 The nestlings begin to call with a soft "peeping." 



