BLACK-THROATED GRAY WARBLER 279 



Food. — No extensive study of the food of the black-throated gray 

 warbler seems to have been made. It is evidently mainly, if not 

 wholly, insectivorous, for several observers have mentioned its zeal 

 in foraging among the foliage of trees and bushes for insects, with 

 a special fondness shown for oak worms and other green caterpillars. 

 Bowles (1902) says that "it seems to prefer oak trees in the spring 

 because of the small green caterpillars that are very numerous on 

 them and which are devoured on all occasions. One female must 

 have eaten nearly half its weight of them (from three-fourths to one 

 and one-half inches long) while its nest was being taken." Mrs. 

 Wheelock (1904) writes in the same vein: "In the spring these oaks 

 are particularly infested with the green caterpillars, and the Warb- 

 lers never seem to tire of devouring the pests. They lean way over 

 to peer under every leaf, or reach up to the twigs overhead, never 

 missing one. Twenty of these worms is an average meal for a Black- 

 throated Gray Warbler, and the total for a day must reach into the 

 hundreds." 



Behavior. — The black-throated gray warbler is not one of the most 

 active wood warblers except when it is busy feeding; even then it 

 goes about it in a quiet, businesslike manner, without much concern 

 over the presence of humans. At other times, it is rather shy and 

 retiring, difficult to follow, as it slips away silently in the thick 

 underbrush, where it spends so much of its time. Its nest is difficult 

 to find, for it is not only well concealed, but the bird is careful not 

 to betray it ; our usual method of following a bird to its nest was not 

 very successful, as it was soon lost to sight while we were watching it. 



Mr. Bowles (1902) writes of its behavior that an incubating female 

 "passed the time eating caterpillars while the nest was being examined. 

 She did not go over five feet from it this time, till I left when she 

 followed for about twenty feet, and kept almost within reach, watch- 

 ing me very closely. * * * Black-throated gray warblers do not 

 object to human association at all ; one nest was fifteen feet up on an 

 oak branch, directly over a trail that was used at least six times a 

 day by people going for mail, and generally much oftener." 



William L. Finley (1904a) describes quite different behavior at a 

 nest containing young : "The moment the mother returned and found 

 me at the nest she was scared almost out of her senses. She fell from 

 the top of the tree in a fluttering fit. She caught quivering on the 

 limb a foot from my hand. But unable to hold on, she slipped 

 through the branches and clutched my shoe. I never saw such an 

 exaggerated case of the chills. I stooped to see what ailed her. She 

 wavered like an autumn leaf to the ground. I leaped down, but she 

 had limped under a bush and suddenly got well. Of course I knew 

 she was tricking me ! But I never saw higher skill in a feathered 

 artist." 



