199 



THE GLEANERS. 



Birds are the natural conservators of our trees. One of 

 their chief offices is the destruction of insects whose rav- 

 ages destroy the foliage or eat the very hearts out of our 

 shade and forest trees. 



Chief among the gleaners of the foliage are the warblers 



Fig. 169. Black and White Warbler entering its nest. 



and vireos; they search the trunks of trees, peer in all the 

 crevices and hang from the tips of the slenderest branches, 

 devouring insect-eggs, worms, caterpillars, larvae and fully 

 developed flies or moths. I have been very fortunate in be- 

 ing able to secure photographic histories of a number of 

 these gleaners. 



Black and White Warbler. 

 Woodpeckers are very expert at climbing up trees; 

 Nuthatches are equally expert at clambering down. Black 



