Service set for opossum kill

Press, 13 November 1985, Page 12

Service set for opossum kill

By

TESSA WARD

The New Zealand Forest service has raised funds for a big opossum-poisoning programme in the rata and kamahi forest of the Copland Valley, south-west of Mount Cook.

The Government had refused to inject more money into the programme but the Forest Service had been able to allocate funds to it from other programmes, said its director of environmental forestry, Mr Murray Hosking. “We have decided to allocate some of the funds we spend on maintenance control of animals, such as goats and wallabies, in some North Island areas, for a single, large programme in the Copland Valley,” he said. “Unless we embark on this opossum control the growing number of opossums will wreak even more havoc on the forest. “Until about five years ago the rata and kamahi trees were free of any opossum destruction. Now we will have to use pre-bait and poison bait aerial drops of carrots to reduce their numbers in the valley about 90 per cent.” The poison would be laid next winter when other food sources for the oppossums

were scarcer, said Mr Hosking.

"Unfortunately, an opossum tends to stick with the same food source, like a mature rata or kamahi tree, until it has been denuded of most of its foliage and usually dies as a result. Beech forests survive opossum foraging better because the beech trees are not the ‘icecream’ that the rata and kamahi trees are to the opossums. “Most Westland forests have some rata but nothing like the Copland Valley’s density of rata trees that produce a vast red forestsmothered spectacle enjoyed by people walking the Copland Track. “After we hit the opossums with our initial intensive control programme we hope to keep' the numbers down with the help of commercial hunting but may have to consider a similar programme in about six years.” The Copland Valley’s isolation and steep slopes made it less appealing to commercial opossum hunters than other regions, said Mr Hosking. “Rata and kamahi forests in other parts of Westland, such as the Kokatahi Valley, near Hokitika, have been so ravaged by opossums that they will never return to their former state. A canopy of different native trees tends to take over once the rata and kamahi have been destroyed,” he said.

“Some of these forests could not be saved when opossums invaded them be-

cause we did not have the technology, such as aerial poisoning, to reduce sufficiently their numbers then.” Control of opossums in the Copland Valley rata forest was as important to the Forest Service as opossum programmes on Kapiti Island and Codfish Island near Stewart Island, said

Mr Hosking. “On both of these islands we need to get rid of opossums to protect the native bird populations. There are some discussions afoot to

re-establish a second population of takahe in the' Fiordland National Park which could require a similar deer programme in the Glaisnock wilderness.”