30 



search them out and destroy them. The sparrows and towhees also 

 search among the dead leaves for caterpillars which crawl on the 

 ground and drop from the trees, and for those which pupate among the 

 litter of the forest floor. Woodpeckers tapping the trunks bring forth 

 injurious ants, bark beetles, wood-boring insects. Creepers, kinglets 

 and nuthatches search the bark and cavities of the trunk and limbs for 

 scale insects, bark lice, borers, bark beetles and the larvae and pupae of 

 insects which hide there. Warblers, thrushes, tanagers, wrens, titmice, 

 vireos, cuckoos and other tree-loving birds pry about among the leaves 

 and branches in search of caterpillars of all sorts. Even the hidden leaf 

 rollers are sought out by the grosbeaks and many other birds and the 

 gall insects are dragged from their hiding places by the jays and gros- 

 beaks. Titmice get the bud worms and woodpeckers search out the 

 worm which destroys the fruit. When the span worms, disturbed by 

 the movements of the caterpillar-hunting warblers, vireos and sparrows 

 among leaves and twigs, spin down on their gossamer threads, and so 

 escape one enemy, they are mai'ked by flycatchers sitting on the watch 

 or hovering in the air ready to dart upon them. When the mature 

 insects, gaining wings, attempt to escape by flight, they are snapped up 

 by these same flycatchers, which sit waiting on the outer limbs of the 

 trees, or, escaping these, they are pursued by the swallows and swifts in 

 the upper air. Those whose flight is nocturnal must run the gauntlet of 

 the screech owl, night-hawk and whippoorwill. Thus birds guard the 

 trees as the summer wanes, until the chill of autumn evenings causes 

 the remaining insects to seek winter hiding-places and warns the birds 

 to begin their southward migrations. Then the tide of bird life turns 

 back, and, passing, leaves the wood in silence, except for the sighing of 

 the branches and the rustle of the falling leaves. In October a few 

 thrushes flit here and there, blue jays mournfully call, a crow caws now 

 and then, but otherwise the woods seem deserted. Still at this season 

 of the year and all through the winter and early spx4ng months the few 

 birds which remain are accomplishing the greatest good for the forest; 

 for now the development and increase of all insects is arrested while their 

 destruction by birds goes on. Another point, the winter birds must sub- 

 sist largely on the hibernating eggs of insects, for many insects pass the 

 winter in that form alone, and the bird that eats these eggs can destroy 

 a hundred times as many insects in this minute, embryonic form, as it 

 could in the summer after the caterpillars had hatched and grown toward 

 maturity. Again, the jays, titmice, nuthatches and woodpeckers, which 

 remain through the winter in the northern woods, must give at least six 

 months more of service to the ti'ees in Massachusetts than the majority 

 of birds that come here as migrants, or as summer residents only. 

 These birds, with the creepers and kinglets, are especially the guardians 

 of the wood. Millions upon millions of insects and their eggs are de- 

 stroyed by them during the long winter months. In this work they are 

 assisted to some extent by the winter finches and sparrows. 



The following notes from the pen of my friend and co-worker, Mr. 

 A. II. Kirkland, are of especial interest, from their accurate description 

 of the manner in which eggs of plant lice are destroyed by winter birds. 



i ' Bird Notes, 



M Birds v. aphid eggs. — Many of our common aphids winter in the egg 

 stage, these eggs being attached to the buds or stalks of the food plants. 

 The large aphid common on willows lays oblong black eggs on the sides 

 of the buds late in the fall. On Jan. 25, 1898, at the Arnold Arboretum, 

 Jamaica Plain, I saw a flock of about half a dozen chickadees feeding 

 on the eggs of this aphid. Some of the birds while feeding came within 

 ten or fifteen feet of the place where I was standing, and 1 could observe 

 plainly their movements. 



