VALUE OF BIBDS TO MAX. 53 



menced bringing food regularly, he began the record at 6 

 A.M. Between 6 and 7 they came to the nest fifty-two times ; 

 between 7 and 8, forty-seven times ; between 8 and 9, forty- 

 tliree times ; between 9 and 10, thirty times ; between 10 

 and 11, thirty-six times ; between 11 and 12, twenty-seven 

 times ; between 12 and 1, thirty-two times ; between 1 and 

 2, thirty-eight times; between 2 and 3, forty-one times; 

 between 3 and 4, twenty-two times ; between 4 and 5, fifty- 

 eight times. The majority of the larvae seemed to be leaf 

 rollers from the oak trees. The female came on the average 

 about three times to each two visits of the male ; he was 

 occupied much of the time in keeping other birds away from 

 the vicinity of the nest. 



When the young of most insect-eating birds are well grown, 

 the parents feed them whole insects just as they are picked 

 up. With a glass, therefore, the insects brought by these 

 Grosbeaks could be seen in the birds' beaks. Their lusty 

 youngsters were fed almost entirely on insect larvae or cater- 

 pillars taken from the forest trees. On only four visits did 

 either parent bird bring less than two larvte each. In eleven 

 hours, then, they made four hundred and twenty-six trips, 

 and must have fed their nestlings at least eight hundred and 

 forty-eight larvae or caterpillars, and possibly more, as a bird 

 has been observed to carry as many as eleven small cater- 

 pillars on one visit to its young. 



In comparing the records of the two nests as given above, 

 it is noticeable that the Grosbeaks fed the young much oftener 

 than did the Vireos. This difi"erence is due mainly to the 

 fact that about the time the young birds are ready to fly, 

 as were these Grosbeaks, they require much more food than 

 when first hatched, as was the case with the Vireos. This, 

 of course, is mainly owing to their increased size. The dif- 

 ference in the number, age, and size of the young probably 

 accounts largely for the great variation in the number of 

 visits made to them by the parent birds, as recorded by dif- 

 ferent observers. 



I have published some notes on the feeding of young 

 Chickadees by the parent birds. Six visits were made to 

 these young within thirteen minutes. In each case the bills 



