BIRDS OF NEW YOUK 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 bam 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 discotirage 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 

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