THE BIRDS 191 



which they are half afraid and, after looking it over sus- 

 piciously, giving the danger chirr which means " beware!" 

 When one chick musters up courage to peck at an object 

 others usually follow its example. If the chick picks up 

 a worm and bolts off with it the other chicks frequently 

 take after the successful one in the endeavor to share 

 its prize. All these acts and also many others are per- 

 formed very soon after the chicks emerge from the egg. 

 The young chick has a number of instincts which equip it, 

 without previous experience, for most of the circum- 

 stances of its life. Hudson relates how the young of some 

 birds will instinctively respond to the parent's call even 

 before they break out of the egg shell. Birds which are 

 active as soon as hatched flock about the mother bird 

 who hunts food for them and gives them a certain pro- 

 tection. By imitating many of the actions of the parents 

 the young learn to avoid enemies and derive many other 

 advantages from their parents' experience. 



In the higher birds, such as the song birds, the nest is 

 built usually of small sticks, twigs and bits of grass and 

 lined with down and other soft materials; and the young 

 which are hatched in a weak and helpless state are fed 

 and tended by their parents until ready to take flight. 

 The common robin, for instance, which is a familiar visitor 

 in the early spring, builds a nest usually in the bough of a 

 tree, and both the male and female birds take turns in 

 sitting upon the eggs which are hatched in about three 

 weeks. The young, of which there are usually from two to 

 five, remain in the nest until they acquire a coat of feathers 

 (for they have but a scanty coat of pin feathers at first) 

 and are then induced by their parents to leave, if they do 

 not do so of their own accord. Herrick in his book on 

 the "Home Life of Wild Birds" describes as follows the 

 behavior of a family of robins whose nest he had carried, 



