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The cause of the rapid disappearance in these islands of some species of birds, and absolute 

 extinction of others, is a very interesting question, and I have already called attention to it in 

 various published papers. In a newly colonized country, where the old fauna and flora are being 

 invaded by a host of foreign immigrants, various natural agencies are brought into play to check 

 the progress of the indigenous species, and to supplant them by new and more enduring forms, 

 more especially in the case of insular areas of comparatively small extent. These agencies are 

 often too subtle in their operation to arrest the notice of the ordinary observer ; and it is only the 

 ultimate results that command his attention and wonder. But in New Zealand some special 

 cause, apart from this general law, must be assigned for the alarmingly rapid decrease of many 

 of the indigenous birds: in the course of a very few years, species formerly common in every 

 gi'ove have become so scarce throughout the country as to threaten to become extinct at no very 

 distant date. 



Various reasons have been suggested to account for this. The natives believe that the 

 imported bee, which has become naturalized in the woods, is displacing the Korimako, Tui, and 

 other honey-eating birds. One of the oldest settlers in the Hokianga district (Judge Maning), 

 speaking to me on this subject, said : — " I remember the time, not very long ago, when the Maori 

 lads would come out of the woods with hundreds of Korimakos hung around them in strings ; now 

 one scarcely ever hears the bird : formerly they swarmed in the northern woods by thousands ; ' 

 now they are well nigh extinct." On asking him his opinion as to the cause of this, he told me 

 that he agreed with the Maoris, that the bee, having taken possession of the woods, has driven 

 the honey-eating birds away from the flowers, and practically starved them out ; and he referred 

 to the scarcity of the Tui, another honey-eater, in support of this view. But it must be remem- 

 bered that both of these species subsist largely on berries and insects, and that the comparative 

 failure of their honey-food, even if granted, will not of itself account for the rapid decrease of 

 these birds ; while, on the other hand, the Totoara (Petrceca albifrons) and other species which 

 do not sip flowers are becoming equally scarce. It appears to me that the honey-bee theory is 

 quite insufficient to meet the case, and that we must look further for the real cause. As the 

 result of long observation, I have come to the conclusion that, apart from the effects produced by 

 a gradual change in the physical conditions of the country, the chief agent in this rapid destruc- 

 tion of certain species of native birds is the introduced rat. This cosmopolitan pest swarms 

 through every part of the country, and nothing escapes its voracity*. It is very abundant in all 

 our woods, and the wonder rather is that any of our insessorial birds are able to rear their broods 

 in safety. Species that nest in hollow trees, or in other situations accessible to the ravages of this 

 little thief, are found to be decreasing, while other species whose nests are, as a rule, more 



* In a letter which I had the pleasure of receiving from the Eev. T. Chapman, of Eotorua, Rome years ago, that gentle- 

 man states : — " Wild Ducks were particularly numerous in this district on my arrival here : you saw them by dozens ; you 

 hardly see them now by twos. I have no doubt we owe this to the Norway rat. There is a place on the "Waikato Eiver, 

 some twenty miles below Taupo, where the chiefs occasionally assembled to act out two important matters, — to discuss 

 politics and eat kouras (crayfish). A few years after the Norway rat fully appeared, the kouras were no longer plentiful ; 

 and as the New Testament made Maori polities rather unnecessary, the usage of meeting no longer exists. The natives 

 assured me that the Norway rat caught the crayfish by diving. Eowing up the rivers you see little deposits of shells : 

 upon inquiry I found they were the selections of the Norway rats, who, by diving for these freshwater pipis, provide a 

 Ichxald (relish) for their vegetable suppers." 



