322 WITH THE U. S. NATURALISTS 



weight, are under the charge of the Warblers and 

 the Vireos. It is of little use for insects to lay 

 their eggs on the tender leaves at the tips of 

 twigs that their young may have sweet foliage on 

 which to feed. Whether the leaves are attacked 

 by larvae, plant-lice, nits, canker-worms, leaf -hop- 

 pers or various sorts of flies, little escapes the 

 searching eyes of the birds. The Warbler takes 

 a quick breakfast or dinner, flitting from tree to 

 tree, but where the hasty Warbler has only been 

 able to find a light lunch, the painstaking Vireo 

 follows and takes a full meal, cocking his little 

 head from side to side to search carefully the under 

 side of the leaves. 



*'The care of the bark of trees is turned over to 

 another group of birds. This is the listening 

 patrol, or, if you please, the sappers and miners 

 of the bird world. These are the birds which use 

 their bills as a mallet and chisel, whose tongues are 

 barbed spears. Woodpeckers leave few grubs in 

 the trees that they attack. The Flicker gorges 

 himself on the larger insects that live on the bark 

 and ants form a considerable part of his diet. 

 The Brown Creeper works his spiral way up the 

 trunk of a tree, really searching for any tiny in- 

 sect, grub or egg which may have been laid in the 



