298 Roosevelt Wild Life Bulletin 



this. One morning, July 21, just after having discovered my only 

 Cerulean Warbler of the summer, I climbed up a hillside on the 

 south side of Quaker Run. A slight ridge sloping down the hill 

 had been cleared for pasture, leaving the edge of a nearly full- 

 grown forest just below me, where I could look down into the 

 tops of the trees (figure 87) with the morning sun at my back 

 giving me the best possible light for observations. I soon heard 

 and then saw a Parula Warbler, one of the most highly colored 

 birds of this species I have ever seen. This bird caught a small 

 caterpillar on the leaf of a butternut tree, took it to a larger limb 

 where it pounded and then swallowed it. In a moment or two it 

 caught another and repeated the performance. Then a female 

 Blackburnian appeared and did the same thing. 



Investigation showed that there were about a dozen butternut 

 trees here, all of whose leaves were infested by caterpillars of some 

 ^eometrid moth. Many holes had been eaten through the leaves, 

 hardly one of which was without its caterpillar. As I sat below 

 one dropped into the pages of my notebook and got folded between 

 the leaves. 



It looked as though the butternuts would soon be stripped of their 

 foliage. But the birds were at work. One after another I found 

 Magnolia, Black-throated Green, Hooded and Black and White 

 Warblers ; Red-eyed, Blue-headed, and Yellow-throated Vireos ; 

 Juncos ; and a female Indigo-bird, all busy gathering caterpillars. 

 A female Magnolia was followed by two young who ate as fast as 

 she could feed them. A Junco was busy carrying her caterpillars 

 to a spot where I suspected there was a nest full of hungry young. 

 The abundance of bright-colored warblers reminded me of a spring 

 morning in May, except for the fact that there were more females 

 and young and singing was less in evidence. 



About two weeks later, on August 5, I again visited this spot. 

 Hardly a bird was to be seen and not a caterpillar. The butternuts 

 were far from defoliated, showing no perceptible difference in 

 appearance than formerly. The birds had done their work thor- 

 oughly. 



Red-eyed Vireo. Vireosylva olivacca (Linn.) 



The Red-eyed Yireo is about the size of the English Sparrow. It 

 may be distinguished best from other Yireos or the several olive- 

 green warblers by the dark line through the eye, the gray crown, 

 white under parts without any tinge of yellow, and the lack of wing 

 bars. The red iris is not easily made out in the field. 



This is tbe commonest forest bird in the Park and is next to 

 the Song Soarrow and Indigo Bunting in general abundance. It is 

 found mainly in the maple and beech woods, but also occurs in oak 

 and chestnut, and in shade trees — particularly maples — about 

 farms and along roads. It lives amid the foliage, gleaning insect 

 food from leaves and twigs. 



The song of this bird is long-continued and persistent. It is 

 made up of short phrases of one to five notes with a short pause 



