HuTTON. — On the Geographical Relations of the N.Z. Fauna. 235 



genera, and the members of the genus Coriphilus are said to live only on 

 bananas. 



That we should have two cuckoos which migrate regularly to other 

 countries, each more than a thousand miles distant, is a fact that deserves 

 special attention, for I know of no parallel case in any other part of the world, 

 the distance across the Mediterranean being less than half that travelled over 

 by our summer visitants. The phenomenon of a bird at a certain season of 

 the year flying out to sea to an island more than a thousand miles distant is 

 remarkable enough, but is rendered still more so in the case of the little 

 shining cuckoo [Chrysococcyx lucidus), which is supposed to come from 

 Australia, by there being no apparent necessity for it. For this bird migrates 

 east and west, and not from a warmer to a colder climate, and two other 

 closely allied species which inhabit Australia never leave the country at all. 

 Even in the case of the long-tailed cuckoo {Eudynamis taitiensis) which 

 comes to us from the equable climate of the South Sea Islands, we cannot 

 suppose that its migrations are caused either by alteration of temperature or 

 by want of food, and the question forces itself upon us — How could this 

 habit have arisen'? The only reasonable hypothesis is, I think, that at 

 one time the difierent lands to and from which these birds fly were con- 

 nected, or nearly so ; that the distance between them gradually increased, 

 and that the habit, so common amongst birds, of resorting each year to the 

 same place to breed, was not lost but gradually merged into a regular 

 migration. From this point of view the arrival of the shining cuckoo 

 indicates a connection with Australia or perhaps New Guinea, while that of 

 the long-tailed cuckoo indicates one with Polynesia, and it must be noticed 

 that while the latter bird is identical with specimens from Polynesia, the 

 former shows such difierences in the colouring of the tail feathers from the 

 birds inhabiting Australia that it is considered by many naturalists to be a 

 distinct species. Another remarkable fact, that has been quite lately brought 

 to light, is that the shining cuckoo of the Chatham Islands is not the same 

 variety as that visiting New Zealand, but is almost, if not quite, identical 

 with an Australian species {G. plagosus). This curious fact proves how 

 strong must be the force of habit, for these birds in their migration to and 

 from the Chatham Islands must pass over, or at least in sight of New 

 Zealand, but instead of stopping, after a journey of 1,400 miles, they continue 

 on for 450 miles more, until they reach the little island that they have 

 selected as their home. 



A more difficult fact to account for is the presence of difierent species of 

 grass-bird {Sphenoeacus) in both Australia and New Zealand, for this bird has 

 such feeble powei'S of flight that it could not cross a river, and must almost of 

 necessity have travelled by land. It must, however, be noticed that this 



