42 FOOD OP THE FLYCATCHERS. 



17 species treated in this bulletin Hymenoptera form the largest 

 item in the stomachs of 13, and may therefore be considered as the 

 typical food of flycatchers. In the consumption of Hymenoptera 

 the olive-sided stands at the head. Nevertheless, Maj. Bendire, in 

 speaking of this bird, says: 



Like all flycatchers, their food consists almost exclusively of winged insects, such 

 as beetles, butterflies, moths, and the numerous gadflies which abound in the places 

 frequented by these birds. 1 



Examination of the stomachs of this species shows that the 3 orders 

 specially referred to amount to less than 12 per cent of its food — 

 another instance of the incompleteness of field observation upon the 

 diet of birds. 



In the investigation of this bird's food 69 stomachs were collected 

 in 12 States, Ontario, Nova Scotia, and New Brunswick during the 

 months from April to September. They are distributed across the 

 continent from New Brunswick to Washington, and as far south as 

 Texas. In the first analysis the food was found to consist of 99.95 

 per cent of animal food and 0.05 per cent of vegetable. This minute 

 portion of vegetable matter is of so little importance that it may be 

 disposed of at once. It consists of fruit pulp, not further identified, 

 to the amount of 3 per cent, and some spruce foliage and other 

 rubbish, all found in 1 stomach collected in Colorado in the month of 

 July. The two latter items amount to 1 per cent, and may both be 

 properly classed as rubbish, probably swallowed accidentally. 



Animal food. — Useful beetles were found in 3 stomachs and amounted 

 to 0.45 per cent of the food. They consisted of 1 tiger beetle (Cicin- 

 delidse) and 2 predaceous ground beetles (Carabidje) and were found 

 in the 3 months of May, July, and August. Beetles belonging to 

 harmful families were found in the diet of every month and 

 amounted to 5.79 per cent of the food. Among these beetles were 2 

 specimens of the cotton-boll weevil (Anthonomus grandis) from the 

 stomach of a bird taken near a cotton field in Texas. Hymenoptera 

 are the staff of life of the olive-sided flycatcher and form a large per- 

 centage of the food of each month. The fewest were taken in May, 

 when they amounted to 74.50 per cent. The average consumption 

 for the season from April to September was 82.56 per cent. They 

 were found in 61 of the 63 stomachs, and 26, that is, over 41 per cent 

 of the whole, contained no other food. Of all the birds examined by 

 the Biological Survey, not one subsists so nearly exclusively upon 

 one order of insects. Winged ants were found in 10 stomachs and 

 entirely filled 2 of them. A few useful parasitic species were identi- 

 fied, but more interesting than these were 63 honeybees (Apis melli- 

 fera), found in 16 stomachs, or 25 per cent of the whole number. Of 

 these, 36 were workers and 27 were males or drones. Thus the, bird 



» Life Histories of North American Birds, II, p. 284, 1895. 



