1056 LIFE : OUTLINES OF GENERAL BIOLOGY 



The Naturalisation of Animals and Plants in New Zealand. Cambridge, 

 1922.) 



Apart from two species of bats, it is doubtful if there are any 

 indigenous mammals in New Zealand; but 48 species have been 

 introduced, 44 purposely and four accidentally. The four include 

 the mouse and three rats, one of which, the Maori rat [Mus exulans), 

 has disappeared since European settlement began. Twenty-five 

 of the 48 species of mammals are at present well established 

 and feral in certain districts — wallaby, common opossum, sooty 

 opossum, pig, horse, red deer, fallow deer, Sambur deer, wapiti, 

 white-tailed deer, moose, cattle, sheep, goats, chamois, cat, ferret, 

 stoat, weasel, black rat, brown rat, mouse, rabbit, hare, and 

 hedgehog. 



About 130 species of birds have been purposely introduced into 

 New Zealand since the date of Captain Cook's landing; and 24 have 

 become truly wild, such as mallard, pheasant, pigeon, skylark, 

 thrush, blackbird, hedge-sparrow, rook, starling, Indian minah, 

 house-sparrow, chaffinch, goldfinch, greenfinch, and yellowhammer. 



On the other hand, since 1868 nine species of birds have become 

 either very rare or extinct, such as native crows, huia, native 

 thrushes, the burrowing parrot (Stringops), the native quail, and 

 the white heron. Others, which were once abundant, have been 

 driven back into areas where there has not been much settlement. 

 As to the causes, Thomson writes: "It must not be supposed that 

 it is the introduced animals alone which have produced this effect, 

 even though rats, cats, rabbits, pigs, cattle, stoats, and weasels, as 

 well perhaps as some kinds of introduced birds, have penetrated 

 beyond the settled districts. It is largely the direct disturbance of 

 their haunts and breeding places, and the interference with their 

 food supply, which has caused this destruction and diminution of 

 the native fauna" (1922, p. 507). 



What is true for birds holds also for lower animals, from lizards 

 to insects; but again the reasons are to be found in human inter- 

 vention rather than in direct competition with newcomers. This 

 is corroborated by the fact that there have been some notable cases 

 of increase during the last fifty years. Thus the bell-bird has become 

 abundant in the South Island, though scarce in the North ; and the 

 harrier has greatly increased, perhaps in relation to the abundance 

 of young rabbits. The grey warbler, yellow-breasted tit, fantail 

 flycatchers, and the pipit or ground lark appear to have more than 

 held their own. The wax-eye or blight bird [Zosterops coerulescens) 

 has increased very greatly since it was first recorded in 1832, 

 perhaps in relation to the supply of animal food about houses and 

 stock-yards. The case of the long-tailed cuckoo [Urodynamis 

 taitensis) is interesting as an illustration of the complexity of inter- 

 relations. It seems to have become increasingly numerous during 



