The Bird Department 



i;v A. A. Allen, Ph.D. 

 Assistant Professor of Ornithology. Cornell i'uizcrsity 



OUR WINTER BIRDS AND WHAT THEY DO FOR US 



Now that the greater part of 

 the country is covered with 

 snow and ice and all nature 

 seems inanimate, one's interest is 

 greatly heightened in the few bits of 

 life that still remain active. Tracks 

 in the snow tell us of the nocturnal 

 wanderings of a few furry mammals 

 that still find food and need not 

 hibernate. A twitter in the hedgerow 

 or a call from the woods announces 

 the presence of some iluffx hall of 

 feathers that has withstood the 

 storms and watched the departure 

 of his fellows; but everything else 

 is sleeping. 



We are constrained to won<ler 

 wli.at law ordains that these few 

 hot-blooded sprites shall brave our 

 winters and eke out their existence 

 in a frugal domant world instead of 

 migrating to a land of plenty. There 

 are some, of course, which feed u]3on 

 seeds and w; can understand how 



AN IXSECT DESTROY I-:R 



A cliickadee searching about an old tent-cater- 

 jiillar's nest for the eggs deposited by the 

 moths before dying. The tent caterpillar 

 passes tlie winter in the egg stage and at this 

 time coimtless numbers are destroyed by the 

 chickadee and other insect-eating winter birds. 



38 



DKAl'lI i).\ i;oUEXTS 



A screech owl. Every owl requires the equiva- 

 lent of- over 1,000 mice a year in order to 

 live, and they are tlie most potent checks 

 upon the increase of the dangerously pro- 

 lific rodents. 



they might still lind fund, and there 

 are some which feed upmi sni,-ill 

 rodents, and these, tmi, we can 

 comprehend. Hut among our winter 

 birds there are some which we 

 know feed almost entirely upon in- 

 sects and it is these that astonish 

 us. lliiw can they find sufficient 

 food even , to supply the energy 

 necessary to keep them warm when 

 every insect has a[)[)areiUlv disa])- 

 peared from the earth? Truly it is 

 one of nature's paradoxes. 



r>ul had we the eyes of birds we 

 would know that insects have not 

 disappeared entirely. The tent 

 caterpillars which denuded our 

 orchards of their leaves during the 

 suninier, transformed into moths 

 before fall, \\bich l.iid their eggs in 

 little varnished packets on the outer 

 branches of the trees. In this stage 

 they are passing the winter ,-in(l ne.xt 

 spring hundreds of little squirming 

 caterpillars will hatch out and begin 

 at once spinning the "tents" to pro- 



tect themselves from the hungry 

 birds. They will thrive and grow fat 

 until e\ery leave is stripped from the 

 branch upon which they were 

 hatched and then they will migrate 

 t<i other branches, until finally the 

 whole tree stands shivering in the 

 summer loreezes. They will acquire 

 lung spiny hairs all over their 

 bodies so that few birds, except the 

 cuckoos, will eat theuL And the 

 next winter there will be hundreds 

 of little packets of eggs instead of 

 one. r>ut at this point a flock of 

 ever-hungry chickadees will happen 

 to come and, with their beady 

 e\es, they will >py out these tiny 

 lunch baskets and, finding food 

 plentiful, they will stay until every 

 egg has been eaten. The next year 

 there will be scarcely a tent cater- 

 pill.-ir on the tree. 



( )r perha])s it was the canker 

 worms that denudeil nur elm trees. 



A.\ ASSAULT ox BOkEKS 



.\ downy woodpecker with a billful of wood- 

 boring larv.-e for its young. In winter as 

 well as summer the woodpeckers go about 

 their work of destroying borers. 



