152 THE STORYLOF THE BRmDs. 
diet is by no means strictly vegetable. Towhees 
scratch in the leaves for grubs, wagtails haunt the 
edge of swamps for little living things, and the 
honey creeper feeds on juices and nectars. 
The warbler forms, into which the finch forms 
grade, feed variously also, but they use little vege- 
table matter. Some have ground-haunting and even 
swamp-haunting habits, others have fringed tongues 
hinting of juices and nectars, while tree-trunk ex- 
ploring, as in the creepers, nuthatches, titmice, ‘etc., 
also prevails. 
The vireos or greenlets are strictly arboreal and, 
having a hook on the beak, they have been thought 
by some to lead toward the butcher bird or shrike, 
which has many of the habits of a bird of prey. Its 
only endowment that way is a strong hooked beak 
and muscular build. It usually kills little birds by 
piercing the brain or snatching off the head or un- 
jointing the neck at the head, and it is so expert at 
it that the motions can not be always perceived—the 
act being even sometimes accomplished while both 
birds are flying. Its food also is mice, grasshop- 
pers, ete. It has the habit of impaling its victims 
on thorns, apparently as a feature of storing or 
hoarding. 
The wrens appear akin to the warbler forms va 
the wren-tits, and are almost exclusively insect or grub 
eaters, sometimes tackling spiders also so large as to 
make quite a battle. 
Thrashers also eat fruit in season. Bluebirds in 
the thrush forms eat fruit in winter only, but the 
