OPOSSUMS IN N.Z.

Hokitika Guardian, 17 November 1920, Page 3

OPOSSUMS IN N.Z.

] REPORT BY PROFESSOR KIRK A report by Professor H. B. Kirk 01 “Opossums in New Zealand” was pre sented to the House of Representative last week. Following are excerpt from the report:— I was asked, through the New Zealand Institute to find -answers to the two following questions:—(l) Whethej the damage to forests is likely to outweigh advantages to settlers in being able to earn a revenue by trapping or taking opossums in new country. (2) On what areas these animals could, be liberated with reasonable security against their over-running and damaging State forests. I am in a positon to answer the questions, as follows: (1) The damage to New Zealand forests is negligible, and is far outweighed by the advantages that already accrues to the community.' That advantage might be enormously greater. On the one hand, the damage to orchards and gardens is indisputable. Much annoyance, and a loss statable at hundreds of pounds, is caused. On the other hand ,the volume of the present trade in skins is statable in thousands, but the loss is borne by one section of the community while the gain from trade is made by another section. (2) Opossums may, in my opinion, with ad_ vantage be liberated in all forest districts, except where the forest is fringed by orchards or 'has plantations of imported trees in the neighbourhood. I have found no native tree that has

in my opinion, been killed by an opos. sum. The favourite plants of the oposn sums are damaged by constant climbing and playing, but this generally happens near houses or at the edge of a clearing; but I have never seen serious dam. age of this kind in the forest. I think it necessarjv to refer specially to the case of the big New Zealand'fuchsia. On Kapiti Island I was shown trees that, had died in. the forest, presumabl killed by opossums although I did not regard the evidence of cause as be. ing conincing, seeing that the trees still

bore abundance of small twigs and that the bark was unharmed. Moreover, the j fuchsia is a very hard tree to kill. I j was told that in the scenic reserve on Lake Kanieri the fuchsia had been killed by opossums. Mr Anderson, the Crown Lands Ranger, kindly accompanied me to this place. We found that although the fuchsias of the forest,.rihge were undamaged and healthy, ■those in the bush, itself were rarely healthy and many were dead. These trees were of all sizes and in various positions with regard to the drainage of the soil, and with regard to shade. Many of them still bore their smaller twigs uninjured, and the bark was in all cases intact. Tfhey presented all the appearance of having died from a bac-

terial or fungo 'disease. Some had been heavily attacked by scale insects. I have not been asked to report upon the damage done by other animals than opossoms, but I should consider myself failing in duty if I made no reference to the matter. In scenic reserves and on other Crown lands cattle aro doing enormous damage. They eat and trample o ut the undergrowth,_aiid their continued presence means death to the forest. Deer, when numerous, are almost as had as cattle. Bigs are very harmful. In some cases rabbits do much damage. None of these animals should be allowed in forest reserves or fn scenic reserves. It is not too much to say that in cases where bush is to he preserved not one head of cattle or deer should be allowed, and pigs should as far as possible he killed. The last commission with regard to State forestry took much evidence on this point. Where the amount of fencing required is small, reserves should be protected by a fence on the sides on which they are open to invasion. In some respects more ranging and perhaps the giving of power to rangers to destroy trespassing animals would lead to the clearance of the forests. The cost of these measures could he met, in part at least, by revenue derived from opossums. Of the opossum naturaised in New Zealand there are two races- —the grey, found in many parts of the Australian Continent, and the brown, (or as it is frequently called, the black, or the blue), especially characteristic of Tasmania. These two races are not distinct species, and there is little doubt that they have crossed in New Zealand. Some of the hybrids, at all events, appear to have fur intermediate in colour between tTie brown and the grey. Opossums are nocturnal in habit, anct during the day conceal themselves in hollow trees or in tufts of plants growing ill i)he branches of trees, or frequently, as far as New Zealand is concerned, at all events, under flry logs, or dry fern, or other plants. Their breeding habits are of considerable importance in forming an idea of the rate at which they are likely to increase, and of what difficulty may be expected in getting rid of them if they should at any time prove altogether undesirable a thing that, in my opinion, will never happen. Opossums breed once in each year, although occasionally there may lie a. second breedings An opossum rarely produces more than one younc animal at a birth and never more that two. So rarely does it Ijappen that two young are produced /in one year that the departures from the .normal state of things must be more than counter balanced by occasional failure to breied, and' by mortality among the young animals. There need, therefore, “be no fear that opossums can over increase in numbers as the rabbit increased in New Zealand. Not only is the rate of increase slow, •but the opossum is so easily trapped,speared, poisoned, or shot, that man could check undue increase speedily and profitably, as is now done lawfully in some open districts and unlawfully in protected districts. Probably no animal is more endowed „with the curiosity that leads it .into danger than the opossum, or is less gifted with the dimming to escape from danger, or even the sense to recognise it.