FLYCATCHER FAMILY. 37 



from rock to rock, and probably it caught an insect on each flight. 

 This activity was kept up all day. Even after supper, when it was 

 so dark that notes had to be written by the aid of the camp fire, the 

 phoebes were still hunting insects. 



Observations like these convince any reasoning person that the 

 number of insects destroyed in a year by this species is something 

 enormous, and the examination of stomachs confirms field observa- 

 tions. This bird eats a higher percentage of insects than any fly- 

 catcher yet studied except the western wood pewee. For the study 

 of this phoebe's food 333 stomachs were available, collected in every 

 month in the year and from various parts of the State. They show 

 99.39 percent of animal matter to 0.61 percent of vegetable. 



Animal food. — In examining the food contained in the stomachs of 

 the black phoebes, account was kept of the beetles that are generally 

 supposed to be useful, namely, the ground beetles (Carabidse), the 

 ladybirds (Coccinellidse), and the tiger beetles (Cicindelidse). It was 

 found that these beetles were eaten pretty regularly throughout the 

 year; in fact, there is no month which does not show a certain per- 

 centage of them. The average for the year, however, is only 2.82, 

 or practically 3 percent, not a heavy tax on the useful beetles. Other 

 beetles, all more or less harmful, amount to 10 percent. They were 

 eaten in every month, and though the quantity varies to some extent, 

 the variation appears to be accidental. 



Hymenoptera amount to over 35 percent of the yearly food. They 

 were found in 252 out of the 333 stomachs, and in 11 there was no 

 other food. They are eaten throughout the year. March is the 

 month of least consumption, with only 1 percent, while August shows 

 the maximum, nearly 60 percent. A few ants and several parasitic 

 species are eaten, but the great bulk of this item is made up of wild 

 bees and wasps. Not a trace of a honey bee was found in any stomach. 



Hemiptera of several families were eaten to the extent of about 7 

 percent. They were pretty uniformly distributed through the food 

 of the year, except that none were taken in May, which, however, is 

 probably accidental. Four of these families are aquatic, which partly 

 explains why the bird is so fond of the vicinity of water. The Redu- 

 viidse are insectivorous, and therefore useful. They were found in 

 but one stomach. The other families are vegetable feeders; all of 

 them likely to be harmful, and most of them pests. The plant lice 

 found in the food are rather unexpected, but, as already noted, fly- 

 catchers do not take all their food on the wing. 



Flies (Diptera) were eaten by the black phoebe to the extent of 

 over 28 percent. They appear in every month, and range from 3 

 percent in August to 64 percent in April. They were found in 127 

 stomachs, 10 of which contained nothing else. The house-fly family 

 (Muscidse), the crane flies (Tipulidae), robber flies (Asilidas), and one 



