FRIENDS OF OUR FORESTS—THE WARBLERS 
By HENRY W. HENSHAW 
With Illustrations from Paintings by Louis Agassiz Fuertes 
T EVERY stage of their growth, 
A from the seed to the adult tree, 
our forest, shade, and orchard 
trees are subject to the attacks of hordes 
of insect enemies, which, if unchecked, 
would soon utterly destroy them. 
What the loss of our forest and shade 
trees would mean to us can better be 
imagined than described. Wood enters 
into so many products that it is difficult 
to think of civilized man without it, while 
the fruits of our orchards also are of the 
greatest importance. Aside from the eco- 
nomic loss, which can hardly be imagined, 
much less estimated, how barren the 
world would seem shorn of our forests 
and beautiful shade trees! 
Fortunately, the insect foes of trees are 
not without their own persistent enemies, 
and among them are many species of 
birds whose equipment and habits spe- 
cially fit them to deal with insects and 
whose entire lives are spent in pursuit of 
them. Many insects at one or another 
stage of their existence burrow deeply 
into the bark or even into the living 
wood of trees, and so are quite safe from 
ordinary bird enemies. Woodpeckers, 
however, being among the most highly 
specialized of birds, are wonderfully 
equipped to dig into wood and to expose 
and destroy these hidden foes. 
Certain insects that largely confine their 
attacks to the smaller branches and ter- 
minal twigs are sought out and preyed 
upon by nuthatches, creepers, titmice, and 
warblers. Others, and their number is 
legion, attack the blossoms and foliage, 
and here the nimble and sharp-eyed war- 
blers render supreme service, the number 
of plant lice and lepidopterous larvz they 
destroy in a single day almost challenging 
belief. 
Thus our woodland songsters are 
among the most important of all our 
birds, and in their own field render man 
unequaled service. Moreover, very few 
have any injurious habits, and the little 
harm they do, if any, weighs as nothing 
in the balance when compared with the 
good. By reason of their numbers and 
their activity in hunting insects, our 
warblers take first place as preservers of 
the forest, and the following account, 
which treats of about half the total num- 
ber, is devoted to the more conspicuous, 
the more important, and the commoner 
species. 
THE WARBLER FAMILY 
Our wood warblers are assembled in a 
rather loosely defined family (the Mnio- 
tiltidee), embracing in all about 140 spe- 
cies, of which more than a third are 
visitors to the United States. They are 
fairly well distributed over the country 
at large, although more species make 
their summer homes in the eastern half 
of the United States than in the western. 
A number of notable species, however, 
summer in the West, as they do also in 
the Southern States. Our New World 
warblers are quite unlike their Old World 
relatives, the Sylviide, or true warblers, 
whose family include some 75 genera 
and between 500 and 600 species. 
Not only do our American species dif- 
fer structurally in many particulars from 
their Old World representatives, espe- 
cially in possessing nine instead of ten 
primaries, but they differ markedly also 
in appearance and habits. It may be said 
in passing that while our warblers are 
brilliantly colored and many of them 
sexually dissimilar, those of the Old 
World are not only small, but plainly 
plumaged; moreover, the sexes are gen- 
erally alike in coloration. 
The larger number of our warblers, as 
well as the most characteristic, are in- 
cluded in the one genus Dendroica, which 
is notable, since it includes more species 
than any other genus of North American 
birds. 
Fortunately for the bird lover, our 
wood warblers are not recluses. They 
are creatures of light and sunshine. Some 
of them, it is true, retire to the mountain 
fastnesses or the depths of coniferous 
forests during the nesting period; but 
