26 THE ANIMALS OF NEW ZEALAND 



The evidence is of a negative pala?ontological character, and it 

 must he used with great caution ; but it seems probable that the 

 godwit and the cuckoo migrated to New Zealand at a time when 

 there were no swallows in existence, and that the original land 

 bridge had been completely broken down before the first of the 

 swallows arrived in Australia from Asia. We may therefore 

 suppose that migration to and from New Zealand commenced 

 in the Eocene Period, when the land stretched away north-west 

 to New Guinea, a time when all New Zealand was joined to the 

 mainland. 



A Happy Family. 



All along the line the effects of isolation are very marked. 

 The absence of land mammals has been already touched upon. 

 The presence of a great many species of birds peculiar to the 

 country is another feature. As time passed, the birds that had 

 come down to these parts found they possessed a land of 

 surpassing goodness. It was free from drought and other 

 disasters with which the faunas of many countries are beset; 

 and abundance of food was easily obtained. Moreover, there 

 were practically no natural enemies. The birds, as a whole, 

 were a happy family. They had their petty quarrels and 

 bickerings, but there was no common foe greatly to reduce 

 their numbers. Life was too easy for them; so many first 

 neglected, and then lost, the power of flight, and dropped into 

 an indolent way of doing things, which became their undoing. 



Excluding the birds from the Chatham and the Auckland 

 Islands, we possess, of the first six orders of land-birds, only 

 forty-five species, and no fewer than about thirty-eight of 

 these are endemic. These forty-five species have been referred 

 to thirt.v-one genera, nineteen of which are found nowhere else, 

 and these thirty-one genera belong to twenty families, two of 

 which, Stringopidae, represented by the kakapo, and Xenicidae, 

 represented by the wrens, are peculiar to New Zealand. Our 

 two owls are also peculiar, and one of them, the laughing owl, 

 belongs to a genus found in no other country; these facts are 

 specially notable, seeing that owls are very widely spread. 



