Hutton. — Our Migratory Birds. 257 



River bed varied but slightly. But Sir W. Buller has re- 

 ceived a specimen from Mr. C. H. Robson which had partially 

 assumed the summer plumage. Mr. Robson also found a pair 

 breeding at Portland Island on the 9th January, and, as he 

 says that the birds undergo little or no change of plumage 

 from winter to summer* (which is a mistake), I presume that 

 the birds he saw were also in the winter or non-breeding 

 plumage. This is very remarkable, for with introduced Euro- 

 pean birds, such as the starling, linnet, and redpole, the 

 change of plumage goes with the breeding-season, as it did 

 in Europe ; both, on coming into the Southern Hemisphere, 

 have changed together. 



We cannot, therefore, think that the birds breeding at 

 Portland Island were true residents, for if they had been 

 long in New Zealand it is probable that they would have 

 acquired their summer plumage in the breeding-season. 



This concludes the list of migratory shore-birds. It is a 

 very short one in comparison with that of Australia ; but if 

 only one species migrated regularly to an island so far away 

 from the mainland as New Zealand it would still be very 

 remarkable. 



I will now proceed to examine the evidence for the migra- 

 tion of our two cuckoos. 



The shining cuckoo, or bronze cuckoo (Chalcococcyx luci- 

 dus), appears in the northern parts of New Zealand regularly 

 in the latter half of September,, and early in October it is 

 found in Wellington and in the South Island. It breeds in 

 New Zealand, and during the first and second weeks in 

 January all the old birds leave the southern portions of the 

 country, but they do not leave the north until the end of 

 January, or perhaps later. Some, at least, of the young birds 

 leave considerably later than their parents, as they have been 

 shot in the South Island in April. The times of appearance 

 and departure of the old birds are wonderfully regular in both 

 Islands. In the Chatham Islands the birds come and go 

 at about the same dates as in New Zealand. Here we have 

 distinct evidence that the birds travel from the north to the 

 south, and then back again to the north. They have not 

 been seen to leave the Islands, but it is impossible that they 

 could remain during the winter and yet escape the eyes and 

 snares of the Maoris, for there are no " wide tracts of un- 

 settled land " for them to go to, as Mr. Wallace suggests, 

 either in New Zealand or in the Chatham Islands. Also, 

 although the birds have not been seen to leave, Mr. T. H. 

 Potts told me that he once saw the arrival of a shining 

 cuckoo at the Chatham Islands. It was so tired when it 



* Trans. N.Z. Inst., vol. xvi., p. 308. 

 17 



