444 The Bird 



species is exposed. 1 believe that this factor is fairly 

 constant for species or tribes of similar habits, and that 

 exceptions indicate peculiarities of circumstances which 

 in many cases we can easily perceive, because I believe 

 that Nature is strictly economical of energy, allowing 

 no more eggs to be laid, and consequently }'Oung to be 

 produced, than the conditions justify in each case. Thus 

 the uniformity of avine population — the balance of bird- 

 life — is maintained." 



When a bird's nest and eggs are destroyed, she will 

 often lay another setting, and some birds raise two and 

 even three broods in a season under normal conditions. 

 If the eggs of a bird are removed as fast as they are laid, 

 the bird will sometimes continue to lav, one of the most 

 remarkable instances of this in an uncaged bird being 

 a Flicker which laid seventy-one eggs during the space 

 of three-and-seventy days. A tiny African Waxbill in 

 captivity has been known to rear fifty-four 3'oung in the 

 course of a year, during the same period laying an addi- 

 tional sixty-seven eggs! The domestic hen has become 

 a veritable egg-laying machine, thanks to careful breed- 

 ing in the past, since the wild Red Jungle Fowl from which 

 all varieties of poultry are descended, lays onl}- one nestful 

 of seven to twelve eggs once a year. 



Many birds still hold to the old style of nesting in 

 hollow trees and such concealed places. Whether they 

 hunt aroimd until they find a cavity ready-made by the 

 elements, or whether, like the woodpeckers, they pro- 

 ceed to excavate a home in a dead branch, or, kingfisher- 

 like, to tunnel deep into a sand-bank, their eggs are almost 



