NATURE AND USES OF POULTRY 7 



has been done in that line, but no such marked general improve- 

 ment has taken place in pigeons as in the common kinds of poultry. 



6. They are completely under the control of man in domestica- 

 tion. In this respect the pigeon affords a most striking contrast. 

 All kinds of poultry can be restrained by fences or kept in yards ; 

 pigeons can be controlled only in cages. 



7. They are dependent upon man for existence in civilization. 

 Aerial birds may maintain themselves in settled districts independ- 

 ently of man. 1 Birds of the poultry group, once domesticated, be- 

 come dependent on man and can exist in contact with civilization 

 only as the property of individuals who protect them. 



The elementary poultry character. The characteristic of terres- 

 trial birds which is of prime economic importance is the condition 

 of the young when hatched. The young of terrestrial birds emerge 

 from the shell full-formed, well covered with down, capable of loco- 

 motion, and able to feed themselves as soon as they require nourish- 

 ment. Thus from the start they are, in a remarkable degree, 

 independent of the parent, while the young of aerial birds, hatched 

 naked, blind, and helpless, are wholly dependent upon the parents 

 until quite full-grown. A high degree of independence in the young 

 of birds which live and nest upon the ground is a necessary condi- 

 tion of that mode of life in a state of nature. In domestication this 

 same characteristic greatly augments their usefulness, permitting 

 important modifications in their habits and making it possible to 

 produce them economically in much greater numbers and under a 

 greater variety of conditions than any other kind of domestic crea- 

 tures. The importance of this characteristic is seen very plainly 

 when we contrast those habits of aerial and terrestrial birds which 

 are associated with the condition of the young, and compare the 

 things which may profitably be done with birds in domestication. 



Young aerial birds require so much attention from their parents 

 that birds of this class are necessarily monogamous in mating habits 



1 It is a fact worth noting in this connection that while the wild pigeon in 

 North America has almost disappeared, flocks of free pigeons maintain them- 

 selves in large cities, where they often make themselves a nuisance, escaping 

 destruction more easily than in the open country because conditions in the city 

 prohibit the use of the weapons most effective in exterminating them. So the 

 little English sparrow, individually insignificant, finds its greatest safety in the cities, 

 where it multiplies amazingly, and efforts to dislodge or exterminate it are futile. 



