Dealing With Opossums CAN RABBIT BOARDS HANDLE NEW TASK?

Press, Volume C, Issue 29459, 10 March 1961, Page 16

Dealing With Opossums CAN RABBIT BOARDS HANDLE NEW TASK?

(Specially written for "The Press" by BJt.C.)

Hopeful that they may repeat their success in reducing the rabbit menace to insignificance. the Government has decided to hand over to the rabbit boards the task of eradicating New Zealand’s major pest of bush and high country, the opossum. Experienced bushmen are not confident of the outcome They regard the discontinuation of the opossum bounty scheme from this month as a mistake, and believe that control by rabbit boards may fail because of the very different charactertistics of opossums and the peculiar difficulties of eradicating them.

On March 31 many trappers will pull down their camps in the remote valleys In the heart of opossuminfested country and make their way out to civilisation. Some may join rabbit boards, accepting positions offered them by the Government in compensation for their loss of livelihood with the discontinuation of the bounty scheme and the eventual devaluation of opossum skins; the rest will seek other back-country jobs. This will end a distinct phase in the war against these pests, which were mentioned in State Forest Service reports of 30 years or so ago as having no important influence on native bush. Earlier, they had enjoyed absolute protection with the blessing of acclimatisation societies because they were “valuable and harmless animals” The Protected Pest

Opossums were introduced a century ago to provide an asset through the sale of their skins. They were established throughout the country through extensive liberations. With large tracts of forest to their liking, absolute protection in

the early stages, and no natural enemies, their numbers increased enormously. One authority estimates that between 1921 and 1945 opossums increased tenfold. These were the years of licensed trapping. Legislation gazetted in May. 1921. described the manner and means by which opossums could be taken under licence, and during an open season proclaimed each year.

The need for better control became evident in the 1940'5, and in 1946 the Opossum Regulations were introduced. These regulations, however, retained the principle of a licence to kill opossums, although brokers’ licences and royalties were dispensed with. In 1947 amendments to these regulations were introduced abolishing the system of licences and permits, leaving the way clear to open trapping for the first time.

For nearly 10 years the bounty system has been in operation. Trappers receive 2s 6d for each token submitted. and are guaranteed 2s 6d if they sell the skins through merchants. This was the first positive approach to opossum control; in recent years it has resulted in the destruction of a million opossums each year. This total, however, is considered barely to represent the natural increase. A Difficult Quarry How will rabbit boards fare in the huge task set them after next month? The present successful structure of rabbit boards, it seems, will not serve the new purpose. Vastly more difficult problems will be encountered in controlling opossums. Unlike rabbits, opossums are found predominantly in bushed gullies and river valleys. They roam only during darkness. not in the late afternoon or early morning when rabbits and other animals are active. They hole up during the day in hollow trunks and other hidden places in the bush, not in burrows which can easily be blocked and fumigated with poison. Rabbit boards rely not only on poisoning; to a great extent they depend on “mopping-up operations”— spotlighting over the country from vehicles, or using dogs and guns. In rugged, steep bush country where opossum infestation is greatest, these methods are impossible. Where rabbit boards can successfully confine rabbits to their area of operations. say between two major rivers and between the sea and the main divide, opossums cannot be kept within such bounds. Higher Costs

Again, most rabbit board employees are married and settled—this is stipulated in many advertised vacancies—and the prospect of many days or perhaps weeks away in the bush laying traps and bait lines would not appeal. The cost of such control methods would certainly be high.

The opossum bounty scheme attracted many experienced bushmen into the areas where the pest was most numerous. Good money could be made from the 2s 6d bounty on each token; and many were content to live for weeks, even for months, far back in the bush. They purchased and carried in their own provisions and gear. The cost to the country was only 2s 6d for each opossum destroyed—£l2s.ooo for the million opossums killed each year. Will these economical and individualistic methods be possible under rabbit board control? Or will there be costly air-drops, transport and provisioning? Will the rabbit boards’ employees on a guaranteed wage get the same kill as trappers under the bounty scheme? The latter were dependent solely on opossum scalps for their income.

Experience may show that the Government would have been wiser to continue the bounty scheme, which has a least kept the pest in check, possibly with a higher bounty —perhaps 3s or 3s 6d—which would attract hundreds more experienced trappers. Several million opossums might be accounted for annually at negligible cost. The change to rabbit board control moreover, may give the pest a respite. It may be a year or more before some concerted form of attack it instituted. During this time the opossums will be virtually unmolested. Rabbit boards will have to be formed in the main areas of opossum infestation, includina most parts of the West Coast where rabbit boards have not operated.