The feral wallaby population in South Canterbury has reached alarming proportions and is spreading beyond the Ecan containment area, according to Environment Canterbury biosecurity team leader Brent Glentworth.

Glentworth said more properties are measuring three on the Guilford Wallaby Infestation Scale. Above level three landowners are given notification by Ecan to reduce wallaby numbers to within an acceptable range. A rating of four assumes there is "a high probability of seeing wallabies," which are by nature a solitary and nocturnal animal.

"Wallaby are now being seen on the south bank of the Waitaki River, and close to the boundary to Mt Cook National Park, well outside of the "containment" area," he said.

"To date we have shot animals on the south side of the Waitaki, and are looking at poisoning near the head of Lake Pukaki. These are areas outside of the containment area."

Wallaby were introduced into New Zealand in 1870. By 1945, concern was mounting over their rapidly building numbers, which were destroying crops and displacing sheep. In 1947 the Department of Internal Affairs initiated control using shooters and dogs and 100,000 wallaby were destroyed over a 10 year period, with little or no impact on the population.

In 1959 rabbit boards and the Wallaby Destruction Committee were formed. The South Canterbury Rabbit Board subsidised wallaby control with a dollar for dollar tax payer incentive and numbers steadily dropped until the 1980s.

However in 1989 the government announced the end of the incentive, and the beginning of a user pays scheme, to which there was considerable opposition.

Farmers opted to undertake responsibility for controlling wallaby on their own. Over the next few years the kill rate was relatively stable, and there were no properties exceeding level three on the Guilford scale.

Peter Moynihan of "Braeval," west of Cave, said in 1978 his property was overrun with wallabies.

"In those days the wallaby board poisoned for us. Since then we have controlled by shooting about 100 a year. I wouldn't say we are overrun but we have cleaned up alot more this year, for some reason."

"We've shot 200-300. I can't tell if it's because the numbers are greater, or because they have been forced into the open because of the drought."

At Hunter Hills Station, Mark Giles, who is on the Ecan pest liaison committee for Cattle Creek, said the problem has been around for a long time, but is just not as evident as rabbits

"I wouldn't say the wallaby problem is worse today in the core areas, but their habitat is spreading. Fourteen years ago you wouldn't see a wallaby on the Haka (Hakataramea) Pass. Now it's common to see them."