82 MAMMALIA 



* Brown Rat; Norway Rat {Mus decumaniis; Epimys norvegicus) 



This ubiquitous animal very early made its appearance in New 

 Zealand, but there is no record of its arrival. Perhaps every vessel 

 which came to the colony brought some immigrants. In the early 

 days of last century Russell or Kororareka in the Bay of Islands was 

 the chief port of the colony, and rats must have become very abundant 

 there. But, as already pointed out, they were probably mostly black 

 rats. Darwin, who visited the Bay of Islands in the ' Beagle ' in 1835, 

 says (p. 428): "It is said that the common Norway rat, in the short 

 space of two years, annihilated in this north end of the island the 

 New Zealand species." Dieffenbach states (vol. 11, p. 185) that he 

 never could obtain a native rat, owing to the extermination carried 

 on against it by the European rat. 



A. R. Wallace in Darzoinism says : 



This invading rat (M. decumaniis) has now been carried by commerce 

 all over the world, and in New Zealand has completely extirpated a native 

 rat, which the Maoris allege they brought with them from their home in 

 the Pacific; and in the same country a native fly is being supplanted by 

 the European house-fly. 



The latter statement is quite erroneous. Native flies have been 

 reduced by introduced birds; certainly not by any other insect. 

 During visits to Stewart Island and the West Coast Sounds between 

 1874 ^'I'i 1880, I was struck by the abundance of these animals in 

 regions uninhabited and almost unvisited by man. One day the late 

 Mr R. Paulin and I emerged from the bush on the south side of Thule 

 in Paterson Inlet when the tide was low, exposing a wide stretch of 

 beach nearly a mile long. We were very much surprised to find 

 the whole beach alive with rats which were feeding on the shell- 

 fish and stranded animals which the tide had left and exposed. As 

 soon as they saw us they immediately ran for the shelter of the bush. 

 They were literally in hundreds. Rats are also very numerous round 

 the homestead on Campbell Island (BoUons). In 1868 H. H. 

 Travers reported them as very abundant in the Chatham Islands. 



A few years ago when a scare arose about the bubonic plague, a 

 feeble and intermittent crusade against rats was inaugurated, but it 

 was, as might have been expected, absolutely futile. While rats are 

 still very abundant, especially about the towns, there is no doubt 

 that the spread of weasels throughout the country has vastly 

 diminished their numbers, especially in the open. 



Rats have had a great share in the destruction of the native avi- 

 fauna, and are also responsible for much of the difficulty experienced 



