HAWAIIAN BIRDS. 13 



causes, since neither bird appears to have ever been the object 

 of pursuit by the natives. 



All the above birds differ so much inter se as to be separable 

 generically, and must have started upon their independent paths 

 ages ago. Like Viridonia, they are more likely to be nearing the 

 close of their respective careers than to be just entering upon 

 them. 



If in the past, when their forest homes were untouched, island 

 birds have suffered from the disastrous effects of inbreeding, 

 how much more marked is likely to be its effect as the available 

 habitat of the birds is more and more restricted by deforesta; 

 tion. 



In this connection it is to be remarked that the species that 

 rove most widely and are most widely distributed in each island 

 and over the islands generally are, with one exception, the ones 

 that are the most numerous and that appear to be the most 

 hardy. In the consideration of such facts it is always easy to 

 confound cause and effect, but here it is clear, at least, that 

 these species are the ones that are least subjected to the penal- 

 ties of inbreeding, be those penalties what they may. Their rov- 

 ing habits, even though these are by no means so marked as in 

 the birds of other lands,, afford opportunity for the mating of 

 birds reared at a distance from each other, even though upon 

 the same island, and under somewhat different conditions of 

 food and climate. 



Still more important to the birds of this class is the possibility 

 of the infusion of fresh blood from the other islands. No one 

 who has studied the habits of the island birds can doubt that 

 the passage of individuals from one island to another is very in- 

 frequent. Still, such instances must occasionally occur, and 

 doubtless tend to strengthen and invigorate the avian stocks 

 concerned. 



Such species as the iiwi, akakani, amakihi and ou are the 

 best examples of the birds of this class, and they doubtless will 

 survive so long as any forests remain. The three former move 

 about to some extent with the change of the seasons, but more 



