38 NEW YORK STATE MUSEUM 



evil. Even where the nests are discovered and moved, or the knife is 

 raised before it has done its fatal work, the nests become an easy prey- 

 to grackles and crows or other marauders before the young are able to 

 leave the nest. Our only escape from this evil seems to be the adaptability 

 of many of the grassland species which finally teaches them to nest in 

 the edges of the field, or to nest earlier in the season, or to rear another 

 brood as soon as the first is destroyed. This, while not a perfect remedy, 

 has worked marvels in many cases which have come under the author's 

 observation where meadowlarks and bobolinks have finally succeeded 

 in inhabiting grasslands in spite of modern conditions of harvesting and 



hay cropping. 



Food of Birds 



Insectivorous species. Of the thirty-two families of land birds found 

 within the State of New York, every one feeds to some extent upon insects, 

 and several families are almost exclusively insectivorous. Among these 

 may be mentioned the goatsuckers, swifts, flycatchers, swallows, vireos, 

 cuckoos, wood warblers, wrens, titmice, nuthatches and kinglets. 

 Of the great order Passeres, which includes almost all our familiar birds, 

 every family feeds largely upon insects during the nesting season, and 

 the young of all are fed upon them. The families which are largely 

 insectivorous but vary their diet to some extent on seeds or fruit are the 

 woodpeckers, larks, blackbirds, orioles, waxwings, tanagers, thrashers 

 and thrushes. Thus it is evident that birds act as the regulators of insect 

 life, maintaining the balance of nature so that vegetation, which is the 

 natural food of the insects, may increase; and it is generally conceded 

 that if the natural enemies of insects were destroyed the result would be 

 the rapid disappearance of all vegetation in the fields and forests We 

 would not maintain for an instant that birds are the only enemies of 

 foliage-feeding insects, for unquestionably among their most effective 

 enemies are unfavorable changes in climatic conditions and the increase 

 of parasitic species which hold them in check to a great extent ; but a study 

 of the food habits of birds, as observed in the field and by examination 



