10 BIRDS OF FIELD, FOREST AND PARK 



site for the nest; and as to choice of location a 

 wide range of preference is made by the various 

 families. 



Some are expert builders, spending much 

 time in the construction of the nest. Others are 

 indifferent workmen, merely gathering a pile of 

 sticks and reeds with little form and no beauty. 

 A few varieties lay their eggs on a bare rock or a 

 flat-roofed house with no nest at all; and one 

 variety, the Cowblrds, lay their eggs in the nests 

 of other birds, leaving the hatching of the eggs 

 and the care of the fledglings to the little mother 

 who has built the nest and has her own brood to 

 care for. The great majority of birds, however, 

 build substantial nests which, in some cases, 

 serve as the home of two broods in a season; and 

 sometimes the nest is used the second season; 

 but this, I believe, does not often occur. Those 

 birds whose young run as soon as hatched are 

 the least expert nest builders. 



The nest completed, the eggs are laid some- 

 times on consecutive days, sometimes with an 

 interval of several days between. Then follows 

 the period of incubation, varying with different 

 species from ten to twenty-one days. During 

 this time the eggs must be kept warm. This re- 

 quires pretty constant attention. With some 

 varieties the female alone sits on the eggs, be- 

 ing fed by the male. With other varieties the 

 male spells her, so that she may seek her own 

 food and rest from her irksome task. You will 

 note when you scare a sitting bird from her nest 

 that either flight or running is difficult at first, 

 the muscles of the wings and legs being stiffened 



