Wallaby control: Otago Regional Council using drones to fight pest

High Country Contracting team leader Stefan Hope and his dog are on the job, following up on drone sightings of wallabies. Photo / Supplied / High Country Contracting

Wallabies are still spreading across the South Island despite control efforts, and while winter conditions can limit wallaby control work on the ground, it is the best time of year to detect the pests using helicopters and drones equipped with thermal cameras.

Otago Regional Council environmental implementation acting manager Libby Caldwell said in recent weeks council contractors had been working in the Livingstone and Shag (Waihemo) river areas using drones and thermal-imaging cameras, and working with hunters on the ground and dogs wearing transmitting collars, to track down and destroy wallabies.

Wallaby populations were first established in New Zealand for recreational hunting in the 1870s.

While there is a 900,000ha containment area for the Bennett's wallaby in South Canterbury, centred in the Hunter Hills and including the Two Thumb, Kirkliston and Grampian Ranges, the animals have been steadily increasing in density and geographic range beyond it since user-pays control was adopted in 1992.

So far this year, ORC has received 22 reports of wallaby sightings from the public, of which 15 were confirmed and eight destroyed.

The sightings were reported across Otago - Lake Hawea, Dunstan Range, Hawkdun Range, North Otago and Dunedin - but most were from the North Otago area.

The eight destroyed wallabies were in Clyde (1), Richmond (1), Boundary Creek (2), Kyeburn (1), and Horse Range (2, plus 1 joey).

Wallabies, which have no natural predators in New Zealand, caused serious damage to the environment, depleting forest understories and preventing native forest regeneration, competing with livestock for food, fouling pasture and damaging agricultural crops and fences, Caldwell said.

The ORC launched its wallaby programme in 2016 when there was a sharp rise in numbers in Otago.

It is part of the Ministry for Primary Industries' national wallaby eradication programme, working in partnership with others in taking a coordinated and strategic approach to eliminate wallabies from New Zealand.

"Wallabies are in Otago now and we need to act fast to stop the spread of this pest," she said.

In terms of the national programme, Otago was the closest to achieving eradication in the short to medium term, but success would rely on members of the public reporting sightings, Caldwell said.

"The public is a vital part of our eradication programme, by reporting sightings," she said.

"If we don't act to eradicate the wallaby population, we face a very real threat to the iconic landscapes that we love here in Otago."

The economic benefit to the South Island of eradicating wallabies was estimated to be more than $23.5million a year - but if action was not taken now, the cost to the economy could escalate to about $67million in 10 years, Caldwell said.

ORC has six contractors undertaking eradication work, using about 50 staff.

To report a wallaby sighting, visit reportwallabies.nz