NORTHERN BLACK-THROATED GREEN WARBLER 299 



eating caterpillars of various kinds, and plant-lice. Evidently these 

 warblers are among the best protectors of our forest trees. W. B. 

 Barrows (1912) says that they are "particularly fond of the 

 berries of the poison-ivy, and to a less extent of those of the 

 junipers." J. K. Terres (1940) saw them tearing open the nests of 

 tent caterpillars, devouring large quantities of the larvae, which were 

 about three-quarters of an inch long. 



Behavior. — Although the black-throated green warbler is one of our 

 tamest and most confiding wood warblers, as shown by the intimate 

 studies of its home life made by several observers, it is much more 

 often heard than seen, for it is a tiny mite and spends most of its 

 time in the tree-tops, gleaning in the foliage of both coniferous and 

 deciduous trees. As Miss Stanwood (1910b) says: "The bird is quick 

 in its movements, but often spends periods of some length on one 

 tree, frequently coming down low to peep inquisitively at an observer, 

 once in a while flying toward a person as if to alight on his hand or 

 head." Forbush (1929) draws a picture of its confidence: "Like all 

 the wood warblers it is fond of bathing, its bath tub often some pool 

 in a mountain trout brook. One day as I stood beside such a brook, 

 a very lovely male, disregarding my presence, alighted on a stone at 

 my feet, and at once hopped into the clear spring water and performed 

 his ablutions, dipping into the stream and throwing off the sparkling 

 drops in little showers. As he stood there in the sunlight which 

 streamed through an opening in the tree-tops, he left an enduring 

 picture in my memory." 



Those who have studied the home life of the black-throated green 

 warbler have noted its intolerance of some avian intruders in the 

 vicinity of its nest, and its tolerance of others. Pitelka (1940b) writes : 



On the eighth day after the hatching, a red squirrel (Sciurus hudsonicus) was 

 observed to approach the blind, coming to within seven feet of the nest. At this 

 time, the female simply left the vicinity of the nest at once and gave no alarm 

 notes. Later the same day, when a young Black and White Warbler approached 

 the nest to a distance of five feet, the female pounced upon it and struck with 

 considerable force. When the intruder returned a second time the female flew 

 at it and drove it away. The indifference to red squirrels and at the same 

 time the offensive reaction toward small passerine intruders {Vireo olivaceus 

 and Penthestes atricapillus) has also been noted by the Nices (1932: 160). 



Reading and Hayes (1933) write: "While at the nest, we noticed 

 an inquisitive Chestnut-sided Warbler in a maple a short distance 

 away. He hu.ng around for several minutes, peering at us, until 

 suddenly the male, ably seconded by his mate, attacked him and drove 

 him off. A male Blackburnian met the same fate a little while later, 

 while peacefully hunting insects in the big spruce and, about an hour 

 after that a Red-eyed Vireo changed his intended route at the first 

 warning note and promptly witlidrew. Curiously enough, a small 



