CHAPTER 38 



The Adaptation of Animals 

 to the Environment 



A COMPLETE discussion of the many ways in which living things have 

 become adapted to overcome or neutrahze deleterious aspects of the 

 environment or to take advantage of favorable factors would fill a large 

 library. In this chapter we shall describe and give examples of some of 

 the general types of adaptations developed by animals to the physical 

 environment and to other living things. 



Careful study of any group of animals shows that some have gen- 

 eralized structures which can be used to survive in a wide range of en- 

 vironments. Others animals are highly specialized for some particular 

 mode of life. Many insects, for example, have become adapted to living 

 in one region and feeding on one sort of material— one or a few kinds of 

 plants. The mouth parts of certain insects are adapted for sucking nectar 

 from certain kinds of plants; others are specialized for sucking blood, 

 for biting, or for chewing vegetation. The bills of various kinds of birds 

 and the teeth of various kinds of mammals may be highly adapted for 

 particular kinds of food (Fig. 38.1). Animals that are highly specialized, 

 adapted for a very narrow ecologic niche, will have some advantage as 



Finch 

 (Seeds) 



^ Hawk 

 (Predatory) 



Whip-poor-vy^ill 

 (Catches flying insects) 



SKiramer 



(SHims over su.rf ace 

 of water) 



K Woodcock 

 (Probi-ng) 



Figure 38.1. Diagrams of the bills of a variety of birds, illustrating their adapta- 



tion to the type of food eaten. 



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