In recent weeks, Otago Regional Council contractors have 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 a 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 since user-pays control was adopted in 1992.
During the 2021/22 financial year, ORC received 38 reports of wallaby sightings from the public, of which 24 were confirmed and 8 destroyed. The sightings were reported across Otago — in 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 had 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, ORC environmental implementation acting manager Libby Caldwell said.
"Wallabies are in Otago now and we need to act fast to stop the spread of this pest," Mrs Caldwell 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, Mrs Caldwell said.
"The public are a vital part in our eradication programme, by reporting sightings.
"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."
ORC has six contractors undertaking eradication work, using about 50 staff.
At night, and particularly in winter when the cooler temperatures make it easier to see wallabies, drone operators use thermal image cameras to track the pests down. Helicopters equipped with thermal cameras are also used in early morning and late afternoon to search areas where signs have been detected, and in areas which are remote or inaccessible.
Everyone is linked to an app called WALL-IS, which puts everything on the national wallaby database to map areas which have been searched.
To report a wallaby sighting, visit reportwallabies.nz.