Itelations of the Xezc-Zecdand Fauna. 33 



climate is quite suitable for tliem. The absence of Polynesian 

 forms is not so remarkable, as thej belong chiefly to more tro- 

 pical genera, and the members of the genus CoripJiilus 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 {Chryso- 

 coccyx luciduSj 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 taitiensi's), 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 tempera- 

 tm'e or by want of food ; and the question forces itself upon 

 us. How could this habit have arisen? The only reasonable 

 hypothesis is, 1 think, that at one time the different lands to 

 and from which these birds fly were connected, 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 connexion with Australia or 

 perhaps New Guinea, while that of the long-tailed cuckoo in- 

 dicates one with Polynesia ; and it must be noticed that, while 

 the latter bird is identical with specimens from Polynesia, the 

 former shows such differences in the colouring of the tail- 

 feathers from the birds inhabiting Australia, that it is consi- 

 dered by many natui'alists 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 Xew Zealand, but is almost, if 

 not quite, identical with an Australian species {C. plagosus). 

 This curious fact proves how strong must be the force of 

 habit ; for these birds in their migration to and from the 

 Chatliam Islands must pass over, or at least in sight of, New 

 Zealand ; but instead of stopping after a journey of 1400 miles, 

 they continue on for 450 miles more, until they reach the little 

 island that they have selected as their home. 



Ann. ct- Mag. N. Hist. Ser. 4. lu/. xiii. '6 



