Monday 1 August 2022
People in the Livingstone area would have seen a drone in the sky after dark and dogs and handlers on the ground during the past week.
Winter is the best time to use aerial methods to hunt these Aussie imports; which have no natural predators in New Zealand, says Otago Regional Council’s Acting Manager, Environmental Implementation Libby Caldwell.
“Wallabies are in Otago now and we need to act fast to stop the spread of this pest,” she says.
While winter conditions do limit on-foot access to areas of the Otago high country, this is the time of year when helicopters and drones equipped with thermal cameras can be best utilised.
Wallabies are causing serious damage to our environment, depleting forest understories and preventing native forest regeneration, competing with livestock for food, fouling pasture, and damaging agricultural crops and fences, says Mrs Caldwell.
It’s a national pest problem and ORC is part of 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.
Mrs Caldwell says in terms of MPI’s national programme, Otago is the closest to achieving eradication in the short to medium term, but success relies on the public reporting sightings.
“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,” she says.
It’s predicted that the economic benefit to the South Island by eradicating wallabies is more than $23.5 million a year.
Mrs Caldwell says if we don’t take action now, the cost to our economy will escalate to around $67 million within 10 years.
Otago has the Bennett’s wallaby, which is the largest species of wallaby. It stands up to 800 mm tall, with a tail of slightly shorter length, and adults can weigh from 15 kg to 25kg.
Sightings in Otago are on the increase for this fast-breeding pest, Mrs Caldwell says.
Bennett’s wallaby is primarily a grazer, feeding on a wide variety of indigenous and exotic grasses and herbs, but it also browses palatable shrub and tree species.
When people report a wallaby sighting to the ORC, or via the Report Wallabies website, a team will be dispatched to the area within 24 hours, Mrs Caldwell says.
ORC contracts pest control specialists that use a mix of tried-and-true boots-on-ground and newer, high-tech methods. Ground surveillance teams look for wallaby scat and sign, and actual wallaby, using hunters and detection dogs during the daytime.
At night, and particularly in the winter when the cooler temperatures make it easier to see them, drone operators use thermal image cameras to track the animal down, working with a hunter on the ground and a dog wearing a transmitting collar. Helicopters equipped with thermal cameras are also used in early morning and late afternoon to search areas where sign has been detected, and in areas which are remote or inaccessible.
Everyone is linked to an app called WALL-IS, quick capture software which puts everything on the national wallaby database, so the teams can map the areas which have been searched.
Here in Otago, the terrain can make wallaby eradication challenging.
Wallabies live in some very hard to access areas. ORC’s contractors are often searching for one wallaby across several hectares of dense bush, scrub or tussock grassland, which is why having new technology in the toolbox, such as infrared cameras and drones, is a bonus.
Wallabies are very cautious and don’t stand in the open like deer or hide up a tree like a possum. Wallabies will feel the dogs before they hear them, as their main sense is vibration because they have their tails on the ground. They will also thump the ground with their tail to warn other wallabies that humans and dogs are around so they can hide in depressions in the ground.
Wallaby sightings are currently most common in North Otago, the Maniototo, Hawea, and Lindis areas.
Go to the Report wallabies website – a team will be dispatched to the area within 24 hours.
In terms of New Zealand’s national pest problem, the ORC’s work is not in isolation. The Council has six contractors undertaking eradication work with about 50 contract staff.
It’s an important part of protecting New Zealand’s biodiversity, natural and production environments, and in this case Otago’s iconic landscapes from pest wallabies.
Biosecurity New Zealand (MPI) funds the National Wallaby Eradication Programme, and the Otago Regional Council’s wallaby eradication programme sits within this. Because of this investment, when a wallaby is reported in Otago, a team is dispatched to deal with it as soon as possible.