THE STRUCTURE AND ACTIVITIES OF BIRDS 355 



the plovers, such as the killdeer, scrape a little hollow in the 

 ground in a field or near a stream, making very little effort to 

 form a real nest (Fig. 220); and many birds, for example the 



Fig. 235. — Two young red-tailed hawks, 10 days old, in nest shown 

 in Fig. 226. (Photo, by Hegner.) 



whippoorwill and certain sea birds, make no nest at all, but 

 lay their eggs on the bare ground '(Fig. 221). 



A few species make their homes in burrows in the ground; 

 of these the kingfisher (Fig. 222), bank swallow (Fig. 223), and 

 burrowing owl are common examples. 



Nests built in bushes or trees must be able to withstand the 

 fury of storms and are consequently more strongly constructed. 



