TRANSFERRING RARE BIRDS.

Forest and Bird, Issue 27, 1 July 1932, Page 10

TRANSFERRING RARE BIRDS.

(By Captain E. V. Sanderson.)

Bird students of the individual bird are prone to advocate the transference of rare birds to sanctuaries in order to save threatened extermination. But there are two sides to this matter, and the advantage of transferring them to an island sanctuary is that they are free at least from the attacks of stoats and weasels in some cases. Resolution Island is said to be an exception to this rule, and there is no doubt that an island requires to be a considerable distance from the mainland in order to avoid these animals obtaining access. Island sanctuaries, however, are not* themselves free from undesirable enemies and frequent reports state that Little Barrier has a numerous wild cat population. Unless steps are taken to check this evil they will of course increase, having no natural enemies, and finally menace the existence of the bird life on the island. Both this island and Kapiti Sanctuary are fully stocked, and it does not seem politic to keep thrusting extra species on to an already fully stocked area. Kapiti, too, has its enemies against wekas, kiwis and kakapo. besides which rats are present in extraordinary numbers, and those on the island inform me that nests are depleted of their contents time and time again. In past years many different species have been introduced on to this island, and it cannot be said that they have prospered. Some indeed have never been heard of again, while only one kakapo has been seen in many years. Notice should certainly be taken of the sayings of that eminent young scientist, Dr. Myers, now holding an onerous position in the British Museum. He says: “The mania for acclimatisation, or the establishment of foreign animals and plants, perhaps more prevalent in New Zealand than in any other country, is a most insidious form of vandalism. In reserves and national parks it is a sin against posterity, and an everlasting reproach to New Zealand, that such a process should not only be allowed, but should actually in many cases be deliberately and actively encouraged by persons of authority, whose patriotism, scorning those natural beauties which embody the very spirit of our country, rises no higher than a desire to create in New Zealand a paltry imitation of other lands. “There is another very dangerous side of the acclimatisation question which should not be overlooked. Once a sanctuary is created in a favourable situation there is a regrettable tendency to stock it, or wish to stock it, with species of native birds not already present, but confined to different localities, or even to other islands. In the case of the confusing medley of species and varieties in the kiwis ( Apteryx ) and the wekas (Galliralius) this practice leads inevitably to inter-breeding.

and perhaps prevents for ever the elucidation of puzzling forms. It is species we should preserve —not mongrels.” After all very little is known of the habits of our rare birds in New Zealand, and it must be evident that the area where the bird is making its last stand against the inroads of civilisation must be adapted to the bird’s food and other requirements. Dr. Cockayne tells us that the plant life in New Zealand varies in a remarkable manner in comparatively adjacent areas, which fact probably accounts for certain species inhabiting particular localities, as witness the Huia being found only along the mountain range between Wellington and Hawkes Bay. Presumably its necessary routine of food supply was procurable only in its habitat. Therefore, it appears that the methods adopted in older and more experienced countries than New Zealand are likely to be more successful than this aviary notion of transferring numbers of species on to sanctuaries where they have never been known to exist. This method is to make a sanctuary of the area where the threatened species still exists. Then put a competent man or men in charge to destroy exotic enemies, keep out collectors, poachers, etc., and generally assist the dying species in its last fight against the inroads of the white man. This method saved the stitchbird in New Zealand, the egret in Egypt, the eider duck and whistling swan in Canada, etc., etc., while the saving of the trumpeter swan is now being undertaken in Canada; and tfiese threatened species did not increase by one or two dozen, which is the best one could expect on a small sanctuary, but by thousands, and to these numbers in a remarkably short period. Surely then with these facts in mind, the pros and cons of this transferring of birds, which it is noticed is condemned by the Conservation Commission of California, should be carefully considered before taking action and spending time and money when dire and urgent needs receive scant or no attention, such as the German owl, deer, goat, and other menaces. It must also be borne in mind that most individual pairs of birds have their territory and keep other members of the same species or those of similar food habits, out of their territory if possible. Thus the transferred bird or birds have to establish themselves and fight their way for an area when in poor condition owing to confinement. And with reference to this phase of the matter, it might be stated that the saddlebacks which were liberated on Little Barrier some three years back were harried by tuis on the second day after liberation, and never heard of again, while those liberated on Kapiti are reported as being still present some twelve months back. Bellbirds liberated in Waipoua kauri forest, a most unsuitable area for such birds, have never been reported as being seen since their liberation. Failure, with loss of effort and money, is the usual result of experiments in transferringbirds. Further, out of some thirty species of game birds introduced into New Zealand at considerable cost, only two or three species have survived.