Although reckoned only a few dozen, they are spread over 1000ha of the Gammack Range on the eastern shore of Lake Pukaki.
ECan South Canterbury team leader of biosecurity, Brent Glentworth, doubts they can be eradicated ECan wants to prevent their spread further.
“We try to control them once a year just to keep that population as low as possible.
“There’s no way we can count individuals but last year we poisoned 48 and that was a good result.
“So, I would think there would be less than that left but I can’t put a figure on it. We know there are still individuals there because we can still find their signs,” he said.
“It may seem a lot of trouble to go to for a few individuals or a few dozen; however, if we left them and they became 200-300 and they spread out from there, the job becomes unachievable.”
The population is believed to have come from a deliberate illegal release, probably in 2006 to 2008.
“Some people move pigs around too, as a hunting resource, so it could have been that; or perhaps pets that grew too big and were released,” said Glenworth.
ECan has been trying to control them by hunting every year since the discovery but even hunters with dogs found the them difficult to locate because of vegetation.
The peanut batter baits are placed on stakes about a metre tall in three batches about a week apart.
The first two batches get the wallabies used to the bait and the third will be laced with 200mg of cyanide each.
The campaign is expected to finish in mid-September then workers will remove the uneaten baits.
Warning signs for the public will stay up for another four months.
Bennett’s wallabies were introduced to South Canterbury for recreational hunting in the 19th century.
