VALUE OF BIRDS TO MAN. 



43 



blind, and helpless ; yet in a few days, or at most a few 

 weeks, they have grown to nearly the size of their parents, 

 and produced a perfect 

 suit of feathers, including 

 the strong quills of wings 

 and tail. In a few weeks 

 more they are able to 

 begin a journey of hun- 

 dreds or thousands of 

 miles over land and sea, 

 in their first migration. 



The young of prsecocial 

 birds, such as Grouse, 

 S n i p e and Plover, are 

 able to run about soon 

 after they are hatched. 



Young GrOUSe learn tO fly pig. 19. Young Cedar Birds, less than three 



when quite small, but they weeks old ' 



develop more slowly than do the young of the smaller 

 altricial birds. It is difficult, therefore, to determine the 



amount of food they 

 require, as they leave 

 the nest at once and 

 wander from place to 

 place, picking up 

 their own food. 



The young of the 

 altricial perching 

 birds, however, re- 

 main quite helpless in 

 the nest until nearly 

 fledged, affording an 



Fig. 2O. Young Grouse, just from the egg, but able excellent Opportunity 



towalk - for the investigator 



to determine the amount and character of their food, and 

 to watch the progress of their development. We can learn 

 how much food such young birds require by feeding them 

 in confinement. 



