FRIENDS OF OUR FORESTS 



By Henry W. Henshaw 



Author oe "Common Birds of Town and Country," in the National 



Geographic Magazine 



Illustrations by Louis Agassis Fuertes 



AT EVERY stage of their growth, 



/\ from the seed to the adult tree, 



1 \ 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 warb- 

 lers render supreme service, the number 

 of plant lice and lepidopterous larvae 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 warbeER eamiey 



Our wood warblers are assembled in a 

 rather loosely defined family (the Mnio- 

 tiltidae), 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 Sylviidas, or true warblers, 

 whose family includes 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 



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