ADAPTATIONS 



137 



of his bright feathers. The female consents to be chosen 

 by the one which pleases her. It is believed that the hand- 

 somest, most vivacious, and most musical males are the 

 ones most successful in such courtship. With polygamous 

 animals there is intense rivalry among the males in the 

 mating season, which in almost all species is in the spring. 

 The strongest males survive and reproduce their strength. 

 The most notable adaptation is seen in the superior size 

 of teeth, horns, mane, or spurs. Among the polygamous 

 fur seals (Fig. 71) and sea lions the male is about four times 



FIG. 72. A wild duck (Aythya) family. Male, female, and prsecocial young. 



the size of the female. In the polygamous family of deer, 

 buffalo, and the domestic cattle and sheep, the male is larger 

 and more powerfully armed than the female. In the polyg- 

 amous group to which the hen, turkey, and peacock belong 

 the males possess the display of plumage, and the structures 

 adapted for fighting, with the will to use them. 



79. Adaptations for the defense of the young. The pro- 

 tection of the young is the source of many adaptive struc- 

 tures as well as of the instincts by which such structures are 



