xxvi INTRODUCTION. 



of the introduced species have not been desirable ones, 

 such as the ordinary House Sparrow, which is now found 

 through introduction over most of the world. On the 

 other hand, some have proved very useful and inoffen- 

 sive ; for instance, the European Goldfinch, and against 

 these there is nothing to be said. The idea that intro- 

 duced birds necessarily tend to cause the extinction 

 of the original fauna appears to be a mistake. The 

 native birds which disappear are mostly those which 

 are dependent on the indigenous forests for their 

 existence ; while the introduced forms will thrive 

 in the neighbourhood of man, as he naturally selects 

 such birds as he is accustomed to see, such as the 

 House Mynah {Acridotheres tvistis) of India, as well 

 as the Sparrow. The possibility of some species in 

 newly-settled countries becoming seriously reduced by 

 disease communicated by introduced birds is well 

 worthy of consideration, but this can hardly be avoided, 

 considering that poultry and pigeons can hardly be dis- 

 pensed with by colonists. The best birds to acclimatize 

 are those which are considered good for food or those 

 whose showy appearance assures a demand as cage- 

 birds, with the exception of the Parrots, whose extreme 

 destructiveness puts them out of court altogether. 



Considering the beauty and interest of birds, it is 

 fortunate that they are, on the whole, such desirable 

 animals from the economic point of view. Hardly any 

 are actually dangerous, and comparatively few in- 

 jurious to crops or domestic animals, while the majority 

 do a great deal of good by the destruction of vermin 

 and seeds of weeds, and sometimes by scavenging. 

 Almost all are edible, and some of them furnish some 

 of the best and most easily available animal food. 



The use of their feathers as ornaments is to my 

 mind illegitimate, and ought to be forbidden, except in 

 the case of those species which are reared in domestica- 

 tion, though it must be admitted that no species ever 



