BIRDS OF NEW YORK 259 



of their nestbuilding, so that the scarcity of such nesting sites, which 

 becomes greater and greater in all civilized communities, is multiplied 

 tenfold by the occupation of all the available hollows by the indefatigable 

 sparrow. Although the bluebirds and martins may drive the sparrows 

 from the box which they have occupied for generations, as soon as they 

 arrive in April, nevertheless the sparrows remain in the vicinity and as 

 soon as the martins or bluebirds are out of the box they begin to carry 

 in their nesting material again, in this way harassing the native birds so 

 continually that they succeed in rearing no young. Thus the number of 

 bluebirds and martins that nest in our dooryards or about the village 

 is becoming smaller and smaller. The effect on the abundance of swallows 

 is especially manifest. A farmer closes his barn to keep out the sparrows 

 and the swallows can not enter. So it is evident that all those birds which 

 make their nests about our buildings or in boxes prepared by men are 

 continually crowded out of their nesting sites and driven farther and 

 farther from our habitations. Furthermore, as the number of sparrows 

 increases it is not only these birds that are discouraged, but even the 

 robins, Chipping sparrows, Yellow warblers and various other species. 

 I have noticed on many occasions the sparrows carrying off the nesting 

 materials that the Robin was placing in the crotch of an apple tree, the 

 poor Robin bringing materials day after day, and the sparrows, one pair 

 after another, carrying the materials away as fast as they were brought, 

 to fill up some yawning hollow post or some hole in the eaves of a building. 

 Likewise, they often build their nests on top of Robins' nests and those 

 of other birds. Being clumsy nest-builders they seem unable to start 

 a new nest for themselves in the ordinary crotches of our shade trees, but 

 as soon as a nest has been started by some respectable architect they 

 immediately take possession and pile up their straw and feathers into 

 an unsightly bunch, thus driving away even the crotch builders from our 

 dooryards. It is not only in this direct way that they discourage the 

 nesting of our native birds, but as they increase in numbers they destroy 

 all the available food supply of smooth caterpillars and other palatable 



