286 LOST AND VANISHING BIRDS 



his works. Nothing of the kind. It is man 

 himself that is advancing over the normal area of 

 the doomed species, extirpating as he goes, and if 

 his colonising movements extend sufficiently far as 

 to include the whole of that normal area, that 

 species is lost. It is one of the most important 

 canons of distribution, that species do not retreat 

 from adverse conditions of life, and one that 

 cannot be too well remembered by all seeking to 

 protect indigenous species from extermination, as 

 well as by collectors and thoughtless sportsmen. 

 It will therefore be seen that the more local a 

 bird may be — in the sense of having a restricted 

 area of distribution — the less capable it is of 

 withstanding prolonged persecution or injurious 

 disturbance. A small area may be soon depleted 

 of its avine treasures, and it is this incontrovertible 

 fact that may well make us pause in the rash 

 persecution of so many localised species, or hasten 

 our endeavours for their safety. 



Now, some of the most local of all avine forms 

 are to be found amongst the Humming Birds. These 

 beautiful birds are most abundant in mountainous 

 countries, and many of the species are so extremely 

 local, that a valley, a mountain-top, or an ancient 

 crater is their sole habitat. Many species are 



