LEAST FLYCATCHER 217 



Miss Mildred Campbell has sent me some elaborate notes on her 

 observations made at a nest of young least flycatchers in Michigan, 

 from which I quote as follows : "The adults covered the eggs day and 

 night. The incubating bird's body movements indicated that the 

 eggs were being turned at intervals. Nestlings were hatched on 

 June 29, June 30, and July 1, respectively. The pieces of shell were 

 carried from the nest by the adults. After 24 hours the large- 

 bellied, naked nestling began to stretch for food." 



During the 11 days in the nest a young bird increased in weight 

 from 1.42 to 8.21 grams. Down appeared on the thijd day, pin- 

 feathers on the fourth and sixth days, eyes opened on the eighth 

 day, and on the eleventh day the young bird was completely feathered. 



"The nestlings were fed by regurgitation of both male and female 

 at first. Later a diet of captured craneflies, Mayflies, grasshoppers 

 (mainly nymphs), beetles, spiders, and harvestmen, with some light 

 green food (unidentified) was brought to the young. The nestlings 

 were fed in rapid succession in a more or less definite order. When 

 no attempt was made to swallow food pressed into the young throat, 

 the morsel was removed and placed in another gaping mouth. Dur- 

 ing my observation, the greatest interval between feedings was 54 

 minutes. The birds were fed heavily from 4 : 40 until 10 : 40 a. m. 

 and from 2 : 00 until 6 : 00 p. m. A sudden increased demand for 

 food came just before the young prepared to fly from the nest. 

 Usually one bird was fed per visit, but several times two were fed 

 on the same occasion. 



"The adults fed the nestlings and waited for the voided 'excreta 

 sac', which was picked up and removed from the nest. The rim 

 of the nest became badly worn by the continuous activity, so that 

 the young soon were able to void the 'excreta sac' over the side of 

 the nest. 



"The diurnal brooding period decreased rapidly from day to day. 

 On very warm days the adults relieved one another dui-ing the heat 

 of the day. One and then the other remained astride the nest, with 

 outstretched wings, keeping the young from suffocating and from 

 the torrid rays of the sun. 



"The nestlings pushed and turned, stretched and preened their 

 wings, and spread their tails. Much' of this was done from the rim 

 of the nest, and then the young dropped down in the nest in order 

 to keep from going overboard during this activity. The first one 

 left the nest during the evening of the eleventh day, the second on 

 the morning of the twelfth day, and the third one preened and 

 stretched on the rim and in the bottom of the nest all day. Food 

 was caught as the parents flew by this fledgling. Finally, in the 



