52 



USEFUL BIRDS. 



gitation. The parent birds swallow the food, and probably 

 soften or partly digest it, ejecting it afterwards through their 

 own mouths into the open mouths of the young. No attempt 

 was made, therefore, in this case, to determine the character 

 or amount of the food, for fear of disturbing the parents and 

 interrupting the regularity of the feeding. The birds were 



fed between 7 and 8 a.m. four- 

 teen times ; between 8 and 9, 

 nine times ; between 9 and 10, 

 twelve times ; between 10 and 

 11, seven times; between 11 

 and 12, sixteen times ; between 

 12 and 1, nine times ; between 1 

 and 2, twelve times ; between 



2 and 3, fifteen times ; between 



3 and 4, thirteen times ; and be- 

 tween 4 and 5, eighteen times. 



It will be seen that one or 

 the other parent came to the 

 nest with food one hundred and 

 twenty-five times in ten hours, 

 even when the observer was 

 watching near by ; but this leaves four hours unaccounted 

 for, to fill out the long June day, from dawn to evening. 

 The feeding periods averaged less than six niinutes apart dur- 

 ing the time the birds were watched ; so it seems probable 

 that, had the entire record for the day been kept, at least 

 one hundred and fifty visits to the young would have been 

 recorded. Young birds are fed oftenest at morning and even- 

 ing, or during the hours when these Vireos were not watched. 

 Mr. Mosher watched a pair of Rose-breasted Grosbeaks 

 feeding their young on June 12, 1899. The young were 

 nearly ready to leave the nest, as one of them stood on a 

 branch near its edge. The nest was situated about fifteen 

 feet from the ground, in the top of a slender white birch in 

 the woods. The ground was well covered with hazel bushes 

 about three and one-half feet high, which nearly concealed 

 the observer. During the first half hour he made no record, 

 as the birds were alarmed by his presence. As they com- 



Pig. 24. — Billing, or feeding by re- 

 gurgitation. From Samuels. 



