The Chestnut -Sided Warbler 129 



They are pretty, dainty little objects, as is the case with all Warblers' eggs. 

 In size, they are about two-thirds of an inch long, and half an inch in diameter 

 at the largest place. 



In the latitude of Boston, fresh eggs may usually be found late in May or 

 in the first week of June. 



The Chestnut-sided Warbler feeds almost exclusively on insects. John 

 James Audubon wrote that once in Pennsylvania, during a snow-storm in 

 early spring, he examined the dead bodies of several, and found that their 

 stomachs contained only grass-seeds and a few spiders. The birds were very 

 poor, and evidently were in a half-starved condition, which would probably 

 account for the fact that they had been engaged in such an un-warbler-like act 

 as eating seeds. Ordinarily this bird is highly insectivorous, and feeds very 

 largely on leaf-eating caterpillars. It also collects plant-lice, ants, leaf-hoppers, 

 small bark-beetles, and, in fact, is a perfect scourge to the small insect-life 

 inhabiting the foliage of the bushes and trees where it makes its home. Some- 

 times the birds take short flights in the air after winged insects. It will thus be 

 seen that the Chestnut-sided Warbler is of decided value as a guardian of trees, 

 which is reason enough why the legislators of the various states where the 

 bird is found were induced to enact the Audubon Law for its protection. 



All birds that depend so much on insects for their livelihood as does the 

 Chestnut-sided Warbler are necessarily highly migratory. By the middle of 

 September nearly all have departed from their summer home, which, we may 

 say roughly, covers the territory of the southern Canadian Provinces from 

 Saskatchewan eastward, and extends southward as far as Ohio and New Jersey. 

 They are also found in summer along the Alleghany Mountains in Tennessee 

 and South Carolina. Most of the migrants go to Central America by way of 

 the Gulf of Mexico, and only a comparatively small number travel to Florida 

 and the Bahama Islands. 



The song of the Chestnut-sided Warbler is confused in the minds of some 

 listeners with that of the Yellow Warbler. Mathews says the song resembles 

 the words, "I wish, I wish, I wish to see Miss Beecher." 



Mr. Clinton G. Abbott, writing in Bird-Lore in 1909, told most enter- 

 tainingly of the fortunes of a pair of these Warblers and their nest, which he 

 watched one summer. After telling of finding a nest from which all the eggs 

 had been thrown but one, and in their place had been deposited two eggs of 

 the Cowbird, he says: 



"The nest was found at Rhinebeck, New York, on July 6, 1900, incubation 

 having apparently just started. Four days later I discovered that one of the 

 Cowbird's eggs was infertile; so I removed it from the nest, disappointed that 

 I should not, after all, enjoy the somewhat unique experience of observing 

 two young Cowbirds growing up in the same nest. It was some time during 

 the night of July 13-14 that the first of the remaining two eggs hatched — the 

 Cowbird's of course. The Warbler's hatched between twelve and twelve-thirty 



