BIRDS OF NEW YORK 22/ 



fly more densely at this season than the redwings and grackles. In the 

 evening, Hke these species, they visit the marshes to roost near the ground 

 in the dense reeds and sedges close to the water line. 



In spite of all the good the Cowbird does, however, I can not believe 

 that it is a beneficial species to have about the gardens, lawns and orchards, 

 for, as is well known, it parasitizes all our small song and insectivorous 

 species, thereby destroying the whole brood of the foster parent, and in 

 return for a brood of Yellow warblers, vireos. Song sparrows or some other 

 interesting and beneficial species we have one Cowbird as the result of 

 the foster parent's work. Consequently, although, as Bendire says in 

 his Life Histories, the Cowbird is beneficial when taking into consideration 

 its food alone, it certainly must be reckoned injurious, because the four 

 song birds which would reasonably represent one Cowbird do much more 

 good than the Cowbird to the agriculturist as well as the nature lover. 



The Cowbird begins to deposit her eggs from the ist to the 15th of 

 May and they are often found as late as the loth or 20th of June. Every 

 one of our small song birds is more or less frequently chosen as a foster 

 parent. A list of 91 species in whose nests the eggs of the Cowbird have 

 been found was compiled by Bendire. In this State I have noticed at 

 least 35 species parasitized by this bird, the commonest of which in my 

 experience are the Phoebe, Song sparrow, Towhee, Indigo bird, Red-eyed 

 vireo, Yellow warbler, American goldfinch. Vesper sparrow. Chipping 

 sparrow. Warbling vireo, Redstart and Chestnut-sided warbler. Fre- 

 quently as many as 2, 3 or 4 eggs of the parasite are found in one nest, 

 but in this case only i or 2 or possibly none of the eggs of the nest owner 

 are found with the Cowbird's eggs. The egg, being usually larger than 

 that of the foster parent, receives the greater amount of heat from the 

 incubating bird and consequently hatches more quickly, usually in 10 

 days after being laid. The young Cowbird, also being larger than the 

 rightful offspring, takes more of the food and so in a short time he is left 

 as the sole occupant of the nest. Of all the hundreds of young cowbirds 

 which I have seen being led about and fed by Indigo birds. Song sparrows, 

 15 



