The Development Of N.Z.'s Unique Fauna And Flora

Auckland Star, Volume LXXIII, Issue 171, 22 July 1942, Page 4

The Development Of N.Z.'s Unique Fauna And Flora

The study of the geographic distribution of plants and animals is a fascinating one, for it provides us with a mental picture of the geography of the earth in past geological ages. Man, a late comer to this earth, has during his brief tenancy played havoc with the natural distribution of living things—so much so that the student of the future will be hard put to it to reconstruct the natural flora and fauna of many parts of the globe, particularly in the continental lands where man has been longest in occupation.

By A. y/. B. Powell

In New Zealand, however, the issue is clear cut. European contact and colonisation is all restricted to the past 200 years, and prior to the arrival of the Maoris, who had extremely limited means of effecting introductions, the country had developed naturally from its primeval state. Moreover, geological science points to long isolation of the New Zealand area from other lands, and so. for the most part, our native fauna and flora developed undisturbed by foreign influences. A (jam! Apart During the -10.000.000 years of the Testiary era. when the great rise and development of land mammals occurred elsewhere, New Zealand was a place apart, and in consequence we have no native land mammals apart from a rat and two small species of bats that found their way by chance across the open ocean. What we missed out on by way of accessions from other lands was compensated by a special development of endemic plant and animal groups, and so was built up a fauna and flora that is as distinctive and clear cut as any met with elsewhere. It is doubtful if any other country has a greater natural wonder to offer than our tuatara—not a lizard, but the only surviving member of an ancient saurian reptilian group known as the Rhynchocephalia. The marvel of this survival of a saurian reptile to this present age can be best appreciated by recalling that elsewhere the group became extinct at the end of the Jurassic period, some 150,000,000 years ago. Just how this strange creature and its ancestors survived the innumerable changes, both climatic and structural, to which the New Zealand area has been subjected is difficult to imagine. Changing »w Zealand New Zealand has not had its present form for very long—its area has been subjected to restless changes both in size and elevation of the surface. It was a continent, or, more correctly, the fringe of a continental mass, that stretched away to the west in the distant cretaceous era. It later shrunk to a small archipelago in early Testiary times, and again commenced a period of emergence, accompanied by earth stresses and erosive forces that eventually shaped the New Zealand of to-day. During this shaping of our land, climatic changes took place also —for long periods the climate was subtropical, and for a brief stage considerably colder than now. Through all these changes our flora and fauna sought to become adapted to conditions, stage by stage, and without the influx of new and virile stock from other land areas. Many sub-tropical forms failed to become adapted to cooling temperatures, and thus became extinct.

The majority of the plant and animal groups survived, however, but having long developed in isolation they acquired characteristics rendering themselves distinct from other members of the ppvent stork of which they were originally a part. Strange Birds The kakapo, for instance, belongs to the widely distributed family of parrots, but where else is there a lumbering nocturnal parrot that has practically lost the power of flight and prefers living in burrows to disporting Its plumage on the sunny tree tops? In the now extinct moas and the equally remarkable flightless kiwis we have specialised New Zealand developments that. must have required considerably more territory for their differentiation. The inference is that the ancestors of these birds commenced their development on the former continent of w r hich New Zealand was a part in the cretaceous period of up to 100,000.000 years ago! Certainly the moa was a relative of that group of southern flightless birds, comprising the South American rhea, the South African ostrich, the Australian emu, and the New Guinea cassowary. Yet from the geological evidence New Zealand has remained almost completely isolated for at least 30.000,000 years.

FALL FROM MOVING CAR

Severe head injuries were suffered by Kenneth Mann, aged 5, son of Mr. K. Mann, of Grey Avenue, Mangere East, when he fell from a moving motor car at Papatoetoe yesterday afternoon. He was admitted to the Auckland Hospital, and his condition to-day was serious.