AVES 



269 



The young of some birds are altricial (Fig. 219) and must be 

 cared for and fed by the parent or parents; while others, like 



Fig. 219. The altricial nestlings of the blue jay (Cyanocit'ta crista'ta). 

 (From Jordan and Kellogg, " Animal Life," D. Appleton and Co., Publish- 

 ers.) 



the quail, are precocial and are able to feed and care for them- 

 selves as soon as hatched. 



The nests of birds vary much according to the habitat of the 

 bird and the material available (Fig. 220) . Birds, like men, use 

 the material they find about them. Ground birds use the ma- 



