Nest-Building 147 



at all, but it seems probable that the instincts of both con- 

 cealment and pugnacity were contemporaneous as they cer- 

 tainly were very early in origin, According to my idea, the 

 guarding, evoked by the fighting instinct, and supplemented 

 by the instinct to cover or hide the eggs, is responsible for the 



Fig. 94. Nest of Cedar Waxwing seen from above, illustrating simple 

 construction ; composed of dead grass and weeds. Little more than one 

 third natural size. 



origin of the incubating instinct, which is usually strongest in 

 the female, and often confined to that sex. 



At all events it has been left for the modern bird to develop 

 an ancient practice on a wider if not on a newer scale, since no 

 other animals have ever possessed their special tools in their 

 present form, breast, bills, feet, and wings, and with them 

 the nesting instinct has become not only more general but more 

 highly developed than in any other great order of the animal 

 world. 



The building of the nest usually follows courtship more or 



