NATURE NOTES

Evening Post, Volume CXIII, Issue 112, 14 May 1927, Page 17

NATURE NOTES

NEW ZEALAND BIRDS

THEIR ORIGIN

VIEWS OF LEADING AtTTHQ-

RITIES

(By E. H. D. Stidolph, 8.A.6.U.)

Isolated from the remainder'of the world for counties y-jars, in' a land strikingly deficie,.V_of land: mammkls, the birds of New Zealan4 enjoyed? a, sublime existence. There.'were'no'natural. enemies .lurking, in., the .undergrowth, no members of the cat tribe no rats, nor snakes; in fact,'no vtar. wvorous mammals whatever to "sud. denly seize an unsuspecting ieinber of the feathered population. TW only raids made on the tanks of thY birds were those of their kind—the hajwks, owls, wekas, and skuas—and'wthesfl attacks were negligible.; In actual reality New Zealand was a biria sanctuary in every sense of the word.. Siirda reigned supreme. liife --under Oio'sa circumstances built up a sense if security, and it could not be wondered that this freedom from molestation gave rise to modification in the structure-and habits of the birds, as is. instanced ia the loss of flight of severaVspecies/ia that respect New Zealand'g birds are word-famous. ThequeerJooking, prac tically wingless and taUess, ki#i *the semi-nocturnal and flightless-■ -kakapo. or owl-parrot,.the remarkableWodneu! a nurihcapaljle of flight although pos' sesiang large^ wings, the weakened flight noticeable in some- othier species not to mention the enormous nioa; comparable to the extinct mammoth in- tn« mammal world, gave scientists ample material for study; provided, ornithologists unheard of delights; and branded New Zealand's birds as the iaost remarkable in the world *: : .:. ;■':: •. v

_ The long isolation from-the 1 rept of ths world is v shown: when anrianalysis n*nVt de ?n. th*- Wecies occurring-liere. or. the 104 species of non-migratory birds, 80 per cent, of the species and 47 per cent, of the genera/aria'not found elsewhere, and five families' aifr exclusive, possessions of NetrZealandV During the period of isolation, the original settlers have become modified. : Bnt, from.where was New Zealand' •" populated? The late Captain IVW; r Hutton, F. 8.5., was of the opinion .that: there was a large body of evidence-which went to prove that New Zealand Was'at some former time, probably in the early Eocene; period, . connected by-' 1 a land ridge with New Caledonia, and New Guinea, and there was ample evidence to show that ■ the Tasman Sea.which separates New Zealand from Australia, has been in existence during the whole of the Tertiary eta. It appears- evident that the ancestors of many of the New Zealandbirds must have come along this land ridge froat New Guinea; he.jsaid. For Captain Hutton stated, the' saddleback and huia are starlings allied 'to Calornii of India, the. Malay Archipelago, NewGuinea, and Northern- Australia; ';Tho piopio is a much modified" thrush, and its nearest allies are^ found.in India and Java. The New Zealand ■ wrens have relations in i India, the . Malay; Archipelago, New Guinea, and Northern Australia. The pigeon haj its near. est relatives in India,: the-Malay Archipelago, Polynesia, Northern-- Australia, and New -Caledonia, ..Nestor (a genus^ which /> includ.es fhe kea „ and kaka) is a remarkable lorm, Captain. Hutton said, connecting "the macaws of America : with .the true.'parjrota of Africa. But, as it formerly occurred in Norfolk Island, it "could be auumed that it carao to JVew Zealand from the north. The wood-hen also has a, close ally in Lord^Howe Island.- And further evidence is rprovided by the fact that at the'present time our :migratoiy land and shore birds still-come to us from the-north....- The;.white eye, however, apparently^ "first made: its" appearance in. New Zealandia. 1856, having the Tasman Sea from Australia. Several other: species occurring in the Commonwealth and New Zealand may have crossed the Tasman, Sea, but it was more probable that th« ancestors of most of them came to New Zealand from New Caledonia^ Captaia Hutton contended. •-•■.•■■

"But, in many cases, it"-is "difficult to decide from which- direction . tha rijst" birds came,'' stated Captain B«t. ton,, "for there are "two possible explanations of the cause of the connection between Australian and;'New,Zealand, birds. The ancestors of the* present species may- either have crossed the Tasman Sea, and so have come to New. Zealand-from- the west,, or,therelationship may be due; to; ;,two "br^iefees of emigrants from New Guinea" •onthwards, one of which; passed into An*, tralia, the other into New Zealand. .. There is good reason for thinking that a migration, of land, birds into; New Ztaland from 'the north' tbokj piipe "ia the Eocene period, for-it is highly 'imr probable that New Zealand'was; eyer again connected with the mainland. la the Gligocene and Miocene periods New Zealand stood at a' lower.level than »t the present day by some 3000 Keet; •but in the Older Pliocene it ltd a much greater extent^ and included the Chatham and Auckland Islands, which were- again separated from. New Zealand in the Newer Pliocene, " '

Messrs. G. M. Mathewe >$n&-~jfom. Iredale, two recent' investigators of New Zealand. birds, consider.';iß«£ avifauna very peculiar, due jtp" 16ng' isola- „ tion. The isolation has been once or twice interrupted, and later invasions - have takeu; place, they ■ Stated While the invasions may have been" from the north, there appear to b« good reasons, for allowing.an Antarctic' element still persisting. Messrs. .Mathews and Iredale hold that the noifthiernL.inyasions -are not' easily .iraceablei' lt is possible that some of the -esrfi«rp invasions took place simultaneously^ With an Australian invasion j which would account for some of the .peculiarities, but they do not Ihink that any direct colonisation' of NejvZealf.nd from:' Australia has. taken ,place .except^in. the Undoubted case of the-white"«ye'. Again, Messrs. Mathews and'lredalfr »re~ unable to confirm. the. relationships:- of some of the New' Zealand - species as outlined by Captain Hutto'n 1.. Thiey; einsider the wrens not nearly,'telatiSd to the pittas, the piopi.o's exact relations as unknown, the :huia and saddleback as having little to do with each/other, and still less with the, starlings. 7 •'' It is unfortunate," they- state, "that the New Zealand avifauna should' ---'have been so Untreated in the past that, a mass of misstatements surrounds almost every bird.'' " ' ■ . .