BIRDS OF NEW YORK STATE 143 



Structure and Habits 



Without going into the origin and evolution of birds as a group 

 from the reptiles and the wonderful changes in their bodily 

 structure which have come about in ixsponse to the needs of a 

 flying machine, one can point out many beautiful adaptations of 

 external form which exist today and which fit each bird for the 

 particular life which it leads. It is but necessary to know the 

 kind of food which a bird eats to be able to see how beautifully 

 nature has modified its bill for securing it. If one knows how 

 the bird pursues its food, he will observe the corresponding 

 adaptations of wings, feet, eyes, etc. The following pictures have 

 been arranged so that one can take up topically the most con- 

 spicuous external parts and point out how each is an adaptation 

 for some particular habit. In each case when one has pointed 

 out some particular modification he should encourage the naming 

 of other birds that have similar modifications. 



1 General 



Skeleton of a fowl Nu 4 



Topography of a bird Nu 2 



2 The bill, adapted for different types of food 



o Insects, method of securing, and resulting bill 



(1) Forceps, for picking small insects from leaf and twig 



Black-throated blue warbler Nu WB 



Yellow-throated vireo Nu ViYl 



(2) Scoop net, catching them on the wing 



Night hawk Nu Ni 



Barn swallow Nu SuC4 



Chimney swift Nu SwC6 



(3) Awl, picking them from crevices in the bark 



Nuthatch Nu NuW 



Brown creeper Nu CsB 



(4) Strainer, straining insects from mud and getting aquatic 



plants 



Scaup duck Nu DuS 



Canada goose Nu GpC 



(5) Chisel, chopping out from tree trunks and large 



branches 



Red-headed woodpecker ■ Nu WpSl 



