More than a million dollars has been pumped into the local wallaby eradication programme this past year as the introduced pest continues to wreak havoc country-wide.
The Ministry for Primary Industries says the economic impact of wallaby spread could reach $84 million a year by 2025 but work is under way to eradicate them.
The manager of Biosecurity New Zealand's pest management programme John Sanson says they are a "significant pest" that is threatening New Zealand's habitats and species.
Dama wallabies are found in the Rotorua Lakes and wider Bay of Plenty area, meanwhile, Bennett's wallabies are found in South Canterbury. There are also four types of wallaby on Kawau Island which is located in the Hauraki Gulf: Dama, Parma, Swamp and Brush-tailed rock.
In 2015, The Bay of Plenty Times reported there had also been wallaby sightings in Pāpāmoa, Whakatāne, Ōpōtiki and Ōhiwa. And in the early 2000s, there had been reports of them at Rocky Cutting Rd in Welcome Bay.
Wallabies damage native forests and tussocks, compete for feed with livestock and increase the risk of erosion with their eating habits.
In a bid to stop population increases and eradicate wallabies, the Government dedicated $27.4m of funding between 2020 and 2024 towards a national wallaby eradication programme.
The funding is being administered by Biosecurity NZ (MPI) through partnerships with regional councils, the Department of Conservation, iwi, and landowners.
Dama wallabies grow to a head and body length of 53cm for males and 49cm for females, with average weights of 5 to 6kg for males and 4 to 5kg for females. They were first released locally near Lake Ōkāreka in 1912 and its population has steadily expanded since.
Over the 2020/21 year, $1,365,000 was spent on wages and operational costs for those involved in the Bay of Plenty and Waikato wallaby programme.
Bay of Plenty Regional Council Dama wallaby programme leader Ron Keyzer said contractors worked a combined total of 6017 hours over the past year which equated to 3.9 fulltime employees.
The FTEs have been funded through Crown and both BOPRC and Waikato Regional Council funding.
The costs covered wages and all operational costs such as the use of helicopters, baits, fencing materials and others, with costs varying between regions, Keyzer said.
Work was awarded through a supply panel that had 17 contractors listed, employing about 150 staff. Forty-two staff were actively involved in wallaby control over the past year.
"Supply panel contractors offer a mix of services including dog surveillance, camera monitoring, ground control, aerial baiting, UAV surveillance and shooting," Keyzer said.
"Prior to control work being undertaken wallaby populations must first be located and population densities established using a number of tools including dog surveillance, camera monitoring and more recently UAV surveillance.
"Currently control methods are limited to shooting and two toxins, 1080 and Feratox (encapsulated cyanide). Shooting is used primarily in farmland environments and the toxins are mainly used in bush and scrub areas."
The long-term goal of the project is to eradicate wallabies from New Zealand, with the immediate objective focused on preventing population spread.
There hadn't been an attempt to measure the Dama wallaby population in recent years because monitoring methods were not robust enough, Keyzer said.
"Dama wallaby are highly adaptable and populations can be found anywhere from the top of Mount Tarawera down to sea level," Keyzer said.
"Dama wallabies will move up to 1km in search of good food sources – their dietary preference is good quality pasture adjoining forest areas.
"Given that they are nocturnal and very cautious animals they do need forest or scrub cover to retreat to during the day. In areas where they are not hunted, they can also be sighted at dawn and dusk."
A Federated Farmers spokesman said wallabies were "becoming an increasingly damaging pest" in the Bay of Plenty for farmers.
"They do more damage than their size suggests," he said. "On farmland, wallabies compete with stock for pasture.
"Wallabies feed on native tree seedlings, grasses and ferns to such an extent that over time they will limit the regeneration of some species, potentially altering the structure and composition of our native forests. In exotic plantations, they can damage pine and eucalyptus seedlings."
Biosecurity NZ pest management programmes manager John Sanson said wallabies threatened New Zealand's habitats and species.
"The biggest impact of wallabies is their browsing habit and huge appetite for young plants and seedlings, directly impacting native and plantation forests and pastureland," Sanson said.
"This changes the ecology of our native forests in that they are unable to regenerate to provide habitat for native birds, lizards and insects, or a healthy forest with healthy aquatic ecosystems."
The best way for the public to help was reporting all signs and sightings of wallabies, such as prints, scat, fur, or wallabies themselves — dead or alive.
"Eradication of wallabies from New Zealand is a long-term aspirational goal but is dependent on making improvements to our management methods," Sanson said.
Biosecurity NZ's short-to-medium-term national wallaby eradication programme objectives:
• Prevent the further spread of wallabies and push outlier populations back to the designated containment areas in the regional pest management plan;
• Improve the effectiveness of wallaby management through investing in research to get better detection and control tools;
• Provide regional employment and support opportunities to build workforce capability.