410 BULLETIN 179, UNITED STATES NATIONAL MUSEUM 



activities. A row of shallow cavities along a ledge apparently rep- 

 resents their first instinctive efforts at burrow digging. But the 

 cavities are seldom more than a few inches deep and are used by 

 the birds as resting places. 



The following extracts concerning the food of the young are 

 taken from Leonard K. Beyer's paper on the "Nest Life of the Bank 

 Swallow" (1938), in which he records his observations from a pit 

 blind excavated back of the nests. When the young were freshly 

 hatched his observation was as follows : 



During the hour which I spent in the observation pit the young were fed 

 several times on small flies, the parent placing the food far down the mouths of 

 the nestlings. * * * 



On the next day, the fourth for our observations, feeding went on just as it 

 did the day before, the male foraging while the female remained in the nest 

 to brood the three young. Feeding occurred on an average of twice every five 

 minutes, the diet consisting mostly of small flies and caddice flies. * * * 



As the days passed the character of the food brought to the young gradually 

 changed, probably due mainly to changes in the relative abundance of various 

 kinds of insects in the vicinity. On the sixth day a brood of may-flies emerged 

 along the lake shore and these insects began to appear in the diet [the birds 

 were now flve days old]. * * * 



On the day they were six days old their food consisted mostly of may- 

 flies. * * * 



On July 3 the young, then ten days old, were very active and hungry, 

 stretching their necks, opening their mouths, and calling eagerly for food when 

 an old bird appeared at the entrance. Tliey were fed thirteen times in an hour, 

 the food being practically all may-flies. 



On July 6 Beyer and his assistant spent the entire day in the blind 

 alternating turns. Some of his observations on food and feeding are 

 as follows: 



During the fifteen hours that the nest was under observation food was 

 brought one hundred and fifteen times * * * the length of time between 

 feedings ranged from one to fifteen minutes, averaging somewhat less than 

 five minutes for the day. Several times both parents came at the same time 

 with food. May-flies again seemed to be the main article of diet. Occasionally 

 one would be dropped while being passed from parent to young and it would 

 struggle, in a more or less mutilated condition, along the floor of the burrow 

 toward the entrance. Neither the young nor the old birds would pay any 

 attention to it. During the period from 5 : 00 p. m. to 7 : 00 p. m. feeding 

 occurred more often, many times at only one-minute intervals. But after 7 : 00 

 p. M. no more visits were made by the parents that day. * * * 



From the data secured in the daily observations at the nest can be made 

 certain general statements concerning the life of the Bank Swallow. When 

 the young are first hatched, * * * they are brooded almost continuously, 

 apparently by the female, while the other parent, apparently the male, forages 

 for food. When the male comes with food the female often flies out for a 

 brief time, usually returning by the time he is through feeding the young. If 

 she has not come back by that time he remains to brood them until she arrives. 

 Occasionally she brings food with her. 



