Oliver. — Birds of Lord Howe, Norfolk, and. Kermadec Islands. 217 



dominates, and, as with Lord Howe Island, the species of this and the 

 New Zealand element together far outnumber those of the Australian 

 section ; but again the presence of such important genera as Nestor and 

 llemiphaga turns the scale in favour of New Zealand. Of the seven resi- 

 dent land-birds not peculiar to the island, one — Halcyon vagans — extends 

 to New Zealand; two — Platycercus elegans (perhaps introduced), Ninox 

 boobook — to Australia; while the remaining four are found in both these 

 countries. Australian forms are thus scarcely in excess of others. 



The migrants recorded include the same two species of cuckoo as occur 

 in Lord Howe Island, and five Charadriiformes, two of which are said to 

 be plentiful at certain seasons of the year. Here again an old land-line 

 is indicated. 



All the occasional visitors to Norfolk Island occur in both Australia 

 and New Zealand. Of the five accidental visitors, all are Australian 

 forms, of which three have been recorded from New Zealand as 

 stragglers, and one — Herodias t im or iens is— is resident there. 



There are no species of birds in Norfolk Island whose presence de- 

 mands that the island should at one time have been connected with a large 

 land-area; nor, as far as I am aware, are there any other members of 

 the indigenous fauna or flora of the island whose presence cannot reason- 

 ably be attributed to dispersal by their own means or by accident across 

 a narrow sea. At the same time, as the avifauna shows similar charac- 

 teristics to that of Lord Howe Island — namely, by its large proportion of 

 endemic land-birds and strong New Caledonian - New Zealand affinities 

 — it is evident that both islands received their first land-birds about the 

 same time and b}' the same route. It seems most probable that at the 

 time Lord Howe Island was actually part of the land bridge stretching 

 northwards from New Zealand, Norfolk Island was a detached islet lying 

 off the east coast of the land, and thus received its fauna and flora across 

 a narrow strait. The present contour of the ocean-floor lends support to 

 this view, as Norfolk Island is completely surrounded by deep water — 

 over 1,000 fathoms — while Lord Howe Island lies in comparatively shallow 

 water on the western edge of a submarine ridge stretching from New 

 Zealand to New Caledonia. For reasons of like origin and characteris- 

 tics the avifaunas of Lord Howe and Norfolk Islands proclaim that both 

 islands must be included in the same biological region, and their relation- 

 ships as detailed above decide this to be the New Zealand region. 



Kkrmadec Islands. 



The conspicuous feature of the avifauna of the Kermadecs is its pau- 

 city of land-birds, and what few occur there are of a decided New Zealand 

 character-. There is practically no Australian element represented. 



The migrants include the two cuckoos mentioned above as occurring 

 in Lord Howe and Norfolk Islands, and six Charadriiformes. None occur 

 in any great numbers; thus their presence affords but little indication of 

 the island lying in an ancient land-line. If a large area of land ever 

 existed in this direction, it disappeared before the present islands came 

 into existence.* The occasional and accidental visitors are all common 

 New Zealand species, and all except Anthus novae-zealandiae occur also in 

 Australia. 



The Kermadec Islands are of a typical oceanic character — that is, they 

 were formed by volcanic action in mid-ocean, and have been populated 



* Trans. N.Z. Inst., vol. 20, p. 161 ; vol. 43, p. 531. 



