ARE THEY AN ASSET?

Gisborne Times, Volume LXVIII, Issue 10725, 24 October 1928, Page 7

ARE THEY AN ASSET?

RISK OF DAMAGE BY OPOSSUMS TO FO RESTS.

“It is doubtful 'whether any other country possesses such a history ot mismanagement and lack. of foresight in tho introduction of fauna as New Zealand. Where man introduces mammals' and birds to a new country, without exercising efficient control over them after their successful ectablishment, tho result; is usually detrimental.”

Thus runs an article in the current issue of the official magazine of the Canterbury College School of Forestry, and the writer goes on to apply the arguments to the opossum! That opossums do eat birds’ eggs is an nndisputahle fact, but little information lias been collected as to the extent of such practice. ‘ln the "eighties and "nineties."’

states the article, “various acclimatisation bodies and private persons introduced the Tasmanian and Australian opossums, and they were liberated in several different parts of the. Dominion. They adapted themselves to the new conditions, which were ideal, and multiplied rapidly, spreading over many parts of the country. They were free from their natural enemies, trapping being the only thing which limited their numbers.

‘•The effects of tho opossum on our forests, however, has caused considerable argument. Past reports of the Director of the State Forest Service states that is economic value as a _fur-bearing animal much outweighs vue very slight damage that it causes, and recommend tho extension of the opossum trapping industry by closed seasons m over-trapped areas, and the release of animals in unstocked regions.

“On the other side a number of observers throughout the Dominion report- on damage done by. the opossum both to native and exotic forests and also as to their effect on native bird life. Those who are opposed to the opossums certainly have all biological and silvicultural principles with which to support their argument.

“As the opossum lives on many of the foods necessary for the wel fare of the birds, it may causa much damage in this direction. In ordinary seasons of plenty the effect may be small ; it is in the lean year that it comes into serious competition with tho birds for food supply. By killing kotnkutuku and rata, it reduces the sources of available foods, and the continual presence of the opossum in ■ one > district might result in tho extinction of these species. The opossum was liberated on Kapiti Island in 1897, and by 1919 it bad considerably altered the supply of native bird foods.

“Opossums- are not present in any plantations in large numbers up to the present, but where they iire present they have usually caused some damage. “Before accepting the opossum as an asset and encouraging it, the authorities should take into account every future possibility. When door were liberated, few people thought that they would become the pest thov are now. A healthy stocking of native birds for pollination, seed dissemination and insect control purposes will be required. It is impossible that the opossum, for its fur-bearing qualities, would bo encouraged under" such conditions, where it is a factor (perhaps small), against the regeneration* and permanence of nor timber and protection forests.

“The. supporters of the opossum assume that the price obtainable for the skins will always be sufficient remuneration for the labor expended in trapping them and then they will always be able to be kept under control by trapping. But is this assumption correct? Will there always be a demand for opossum skins, and if so, might It not*be supplied by farming tho, animals under control, with tho production rof skins at a price that would render the trapping of the wild animAl unprofitable? Silver foxes are farmed commercially in Canada, and the production " of rabbit skins in England from rabbit farms is greater in number per annum than that exported from New Zealand—.perhaps the opossum .will he added to the list of commercially fanned 1 animals ?"