BIRDS AND TREES IN WINTER 



47 



leaves. When the caterpillars are full grown they crawl 

 to some convenient shelter and spin cocoons about them- 

 selves and later transform into the brownish moths. The 

 moths then begin a new cycle, laying the packets of eggs, 

 in which stage the insect passes the winter. 



The tent caterpillar is much more easily controlled than 

 the codling moth in the orchard but nevertheless from 

 time to time is exceedingly destructive. In many com- 

 munities men have been hired to pick the egg masses and 

 later the cocoons from the trees and to burn the tents. 

 Competitions among school children have been inaugu- 

 rated resulting in the gathering of thousands of the egg 

 masses, but all of these efforts have been spasmodic and 

 have died out as spontaneously as they have arisen. The 

 eyes of children working at odd moments in the spirit 



WINTER BIRDS CONTROL THE CODLING MOTH 



Here are some species of bark with holes punched through them by a 

 woodpecker to get the hibernating larvae concealed beneath. The empty 

 cocoons can be discerned in the top row showing the undersurface of 

 the bark. 



of competition over the branches which they can reach 

 from the ground cannot compare with the keen eyes of 

 the birds, working at all times over all parts of the trees 

 and working for the very maintenance of life. The little 

 caterpillars when first hatched furnish food for the 

 warblers and vireos and wrens and other small birds on 

 their northward migrations ; the half grown caterpillars 

 with their hairy covering are snatched from their tents 

 by the orioles; and the full grown caterpillars cannot be 

 too hairy or too juicy for the cuckoos that relish them 

 more than any other insects. But it is not only by the 

 summer birds that the tent caterpillars are destroyed. 



Hundreds of embryo caterpillars are destroyed at a sin- 

 gle swallow by the nuthatches and chickadees hunting 

 about the branches during winter and even the crows 

 have been known to eat the little varnished packets . 

 of eggs. 



These are but two of the hosts of insect pests that can 

 be controlled by man but that are much more satis- 



ANOTHER BARK CLEANER 



The white-breasted nuthatch, with us throughout the year and a most 

 useful bird. Here he is in a characteristic pose. 



factorily controlled by birds when they are sufficiently 

 abundant. There is an equally long list of pests that are 

 either uncontrollable by man or that are controlled only 

 by the greatest effort and expense, but that the birds are 

 constantly though unwittingly fighting. There are, for 

 example, the many kinds of destructive borers. It is 

 often impossible to know whether borers are working in 

 a tree until its vitality has been sapped if it is not killed 

 outright. Nature knows this and she has provided the 

 woodpeckers to combat them. She has given them pincer- 

 like feet for clinging to the bark and stiffened tails to 

 support them in their search about the trunk. She has 

 given them chisel-like bills for hacking open the bur- 

 rows and long barbed tongues for pulling out the larvae 

 from their retreats. Nature has gone this far. It is our 

 duty to see that the woodpeckers are encouraged to re- 

 main with us in good numbers. They must have an 

 occasional dead tree in which to nest and to roost and they 

 must have a little extra food during the winter in case 

 their natural food is scarce. So when we are observing 

 upon the winter landscape, marveling at the grace of the 

 wind-swept branches and making our plans for bigger and 

 better forests, and for more shade trees along our high- 

 ways, let us not forget the winter birds. Let us include 

 refuges, and feeding stations and sanctuaries for birds 

 among the much needed civic improvements and let us 

 call no forest preserve complete without its offering for 

 the birds that are to help protect it. 



