26 



BULLETIN OF 



Massachusetts Boaeb of Agriculture. 



BIRDS AS PROTECTORS OF WOODLANDS. 



By E. H. Forbush, Ornithologist to the Board. 

 Illustrated by the Author. 



The greatest enemy of the forest is man himself, for there is no devas- 

 tation of the woodlands which even approximates that which comes from 

 fire or the axe. Against these evils (which are blessings only when well 

 handled) only education and legislation can protect us. We know the 

 injury to the woodlands caused by long droughts, or by cold and storms. 

 From injuries so caused there is no deliverance, neither is there any 

 remedy provided, but the damage from elemental causes usually falls on 

 trees which have passed their age of greatest usefulness, or upon young 

 and sickly specimens. We know that trees are subject to many injuries 

 by animals. Their foliage is eaten by beetles, flies, grubs and cater- 

 pillars ; their fruit and seeds destroyed by insects, birds and squirrels ; 

 their twigs destroyed by borers or cut off by girdlers ; their bark eaten 

 by mice, hares and other animals ; their trunks and roots attacked by 

 wood borers ; and even their very life blood, the sap, is sucked out by 

 aphids. Against such injuries, however, nature provides preventatives 

 or remedies. Some species of trees have hundreds of species of insects 

 feeding upon them. When we consider well the fecundity, voracity and 

 the consequent great possibilities for mischief possessed by the trees' 

 enemies we wonder that trees survive at all. Still, trees spring up and 

 grow apace. In a wooded country a few years' neglect of field or past- 

 ure suffices to clothe it with a growth of bushes and young trees, and 

 in time a wood lot succeeds the cleared land. That trees are able thus to 

 spring up and grow to maturity without man's care is sufficient evidence 

 that they are protected by their natural friends from the too injurious 

 inroads of their natural enemies. 



Among these friends birds hold the chief place. It is generally be- 

 lieved that there are few birds in deep woods. Travellei-s have often 

 remarked the scarcity of birds in the forest, and it is true that usually 

 there are fewer birds, both in numbers of species and individuals, in 

 most northern forests than in more open or cultivated lands. Those that 

 live and breed in the deep woods, however, are especially fitted to de- 

 stroy the trees' enemies, and twice each year, in spring and fall, a great 

 wave of migratory, insect-eating birds, that summer in the north and 

 winter near the tropics, passes through the woods of the temperate zone, 

 gleaning insects from the trees as well as from the plants springing 

 from forest floor, from the leaf mold or from out the very ground. 



Here in Massachusetts, in the chill days of March and early April, 

 when sunshine and shadow fleck the lingering snow, in silent woods and 



