186 USEFUL BIRDS. 
Mr. Robert H. Coleman, in a letter to the Biological Sur- 
vey, stated, according to Dr. Judd, that he counted the 
number of insects eaten by a Palm Warbler, and found that 
it varied from forty to sixty per minute. The bird, he 
said, spent at least four hours on his piazza, and in that time 
must have eaten about nine thousand, five hundred insects. 
I have seen Warblers eating from masses of small insects 
at such a rate that it was impossible for me to count the 
number of insects eaten. When larger insects are taken, 
the time given to each increases. The bird will sometimes 
spend at least ten minutes in the attempt to swallow a 
large caterpillar. It is difficult, therefore, to approximate the 
number of insects eaten by a Warbler in a day, except where 
it is feeding mainly on a particular species. 
In this family we find birds that assume the care of the 
trees from the ground to the topmost twig. Some walk 
daintily along the ground, searching among the shrubbery 
and fallen leaves ; others cling close to the bark, and search 
its every crevice for those insignificant insects which collect- 
ively form the greatest pests of forest and orchard ; others 
mount into the tree, skip from branch to branch, and peer 
about among the leaves or search the opening buds of the 
lower branches; others habitually ascend to the tree tops ; 
while still others are in almost constant pursuit of the winged 
insects that dart about among the branches. We will first 
consider the common ground-frequenting species. 
Northern Yellow-throat. Maryland Yellow-throat. 
Geothlypis trichas brachidactyla. 
Length. — About five and one-quarter inches. 
Adult Male.— Upper parts olive-green ; forehead and mask black, bordered above 
by ashy-gray; under parts mainly bright yellow. 
Adult Female. — Like the male, but without the black or ashy ; under parts paler. 
Nest.— On or near the ground, supported by grass stems, leafy plants, or shrubs; 
deep, and composed mainly of leaves and grasses; sometimes roofed, and 
not infrequently hair-lined. 
Eggs.— White, spotted with brown and lilac at the larger end. 
Season. — May to October. 
This Yellow-throat is a bird of the brookside and swampy 
thicket; but it is not by any means confined to these locali- 
ties, for it is found in the fruit garden and orchard as well as 
