Search and destroy to fight Canty wallabies

Waimate’s wallabies have been put on notice: they are not welcome in Otago’s back yard.

The Otago Regional Council will develop a dedicated searchand-destroy and surveillance programme to crack-down on wallaby incursions from South Canterbury.

It approved a $273,000 budget on Wednesday to beat the pest whose population was slowly spreading south from its traditional stronghold in the Waimate District and inland.

Councillors heard Bennett’s wallabies had the potential to cause significant adverse environmental effects should feral populations take hold — just as they threatened to do in southern South Canterbury.

Wallabies compete with stock for pasture and could damage crops and young trees. They could adapt easily to new habitats and could thrive in any environment from forests through to open tussock country.

Council chief executive Peter Bodeker said the number of confirmed sightings and kills of wallaby south of the Waitaki River and well within Otago was on the increase.

The wallaby population south of the Waitaki River had grown faster than expected, resulting in increased pressure being put on the regional boundary with South Canterbury, he said.

The new plan would see the Otago council work closely with Environment Canterbury to coordinate control programmes on the boundary to prevent a breeding population establishing in Otago.

Bodeker said his council would operate the programme with community and other agencies.

Helicopters will be used for aerial surveillance, council-owned remote sensing cameras would help track the animals and groundbased search operations would be mounted.

Otago Regional Council director environmental monitoring and operations Scott MacLean said landowners had supported that approach and some had offered to help.

Recent signs of wallabies emerging near Alexandra in Cen- tral Otago has the Otago council worried they may be being intentionally released.

Wider sightings pointed to a mixture of natural migration and release, he said.

‘‘We need help from farmers and other residents south of the Waitaki River to be our eyes and ears on the ground,’’ MacLean said.

The Otago Pest Management Plan says wallaby sightings need to be reported to the regional council within two days, and the pests must be destroyed if safe to do so.

Anyone found deliberately releasing wallabies can be imprisoned for up to five years, and/or fined up to $100,000.

Landcare Research wildlife biologist Bruce Warburton, of Lincoln, agreed with the proposed regime.

‘‘The sensible approach is to act early. ORC should be congratulated for acting sooner rather than later. It would have been better if they started even earlier, but now it is good,’’ he said.

Warburton said the Hunter Hills was the core range for wallabies for the past hundred years.

Natural barriers such as rivers stop them spreading.

However, the wallaby population has been allowed to increase on the north side of the Waitaki River to the extent that a few have crossed bridges or dams to the south side and are beginning to spread out.

The Waitaki Wallaby Liaison Group with support of Landcare Research, ECan and ORC have applied for about $300,000 over two years to research and find the most effective surveillance method, Warburton said..

The proposal was submitted last month and is now being reviewed.

Warburton said total eradication is ‘‘technically possible, but very expensive’’ and poses a social challenge because a lot of people like wallabies.

He estimates it would cost about $300-$500 per hectare to eradicate wallabies based on costs to eradicate other pests contained on islands around New Zealand.