34 



destroyed in one day by the family when we take into consideration 

 the food required by the old birds. It is impossible to estimate how 

 many of these insects were hairy caterpillars. 



It will be noted that the grosbeaks made many more visits to the 

 nest and carried much more "food than the vireos. This is accounted 

 for by the age of the young, the viroes being just from the egg and the 

 grosbeaks being nearly ready to fly and very much larger. 



Dr. C. M. Weed, in a paper entitled " The Feeding Habits of the 

 Chipping Sparrow," published at the New Hampshire Agricultural 

 Experiment Station, has given a very accurate record of the feeding of 

 the young of two chipping sparrows during the entire day, beginning 

 at 3.40 a.m. and ending at 7.49 p.m. The nest contained three young 

 sparrows nearly fledged. His observations show that the birds feed 

 their young during the long days of June from fifteen to sixteen hours, 

 and that there was no long interval during the day when they were not' 

 at work. The birds visited the nest one hundred and eighty-two times. 

 Food (mainly insects, including many caterpillars) was brought nearly 

 every time, though some of the trips of the birds seemed to be made to 

 furnish sand for grinding the food for the young birds. 



Comparative Usefulness of Certain Families of Birds. 



In going over the lists of birds which have been seen to destroy differ- 

 ent species of hairy and spiny caterpillars it is interesting to note that 

 nearly the same families are represented in each list. 



The Cuckoos, Cuculidas. 



It is generally acknowledged that the cuckoo is an exception to the 

 generally accepted rule that birds do not eat hairy caterpillars, There 

 is no question as to the value of the cuckoos in this respect, but they 

 feed mainly on the medium-sized and larger caterpillars. The two 

 common. American species seem even to prefer hairy caterpillars to the 

 smooth ones, and their diet of these insects sometimes results in their 

 stomachs becoming lined with the prickly hairs, which become embedded 

 in the stomach coating. This, however, does not appear to inconvenience 

 the birds. Whether there is any other family that is as useful in this 

 respect as the cuckoos is still an open question. Our observations show 

 that great numbers are eaten by other birds. 



The Woodpeckers, Picidae. 



Woodpeckers certainly do not destroy as many hairy caterpillars as 

 the cuckoos. They appear to take them only when they come in their 

 way. They have been observed to maim and kill without eating. 



The Flycatchers, Tyrannida?. 



The flycatchers eat very few hairy caterpillars but destroy a great 

 many of the imagoes of the diurnal species, two kingbirds having been 

 observed to kill about two hundred and fifty male moths of the Porlhelria 

 dispar in less than three hours, and many female moths as well. Many 

 flying moths are destroyed by the flycatchers. 



The Croivs, Jays, etc., Corvidge. 

 This family is represented by the blue jay and crow, both species beino- 

 among the most useful in the destruction of medium-sized and fulf- 

 grown hairy caterpillars. The observations on these birds made within 

 the last three years prove them to be more useful in this respect than 

 was even suspected. They are continually feeding where outbreaks of 

 hairy caterpillars occur, eating both the caterpillars and pupa}, and feed- 



