The shy, nocturnal Dama wallaby may look cute and cuddly, but it’s a major pest issue in the Rotorua area. With sightings from Rotorua east to Kawerau, and south beyond Rainbow Mountain to the Paeroa Range (between Reporoa and Waikite Valley), exact numbers are not known, but the area of the sightings is expanding.
Dama wallabies were introduced to Kawau Island by Sir George Grey in 1870 and later released into the Rotorua area in 1912.
Bay of Plenty Regional Council biosecurity officer Dale Williams manages contractors carrying out wallaby surveillance and control within the Bay of Plenty Region.
“Wallabies eat all seedlings within their reach of some native trees, ferns and grasses. This prevents native forest regeneration, destroying the habitat and food sources of native species. They can also damage newly planted pine and native seedlings.
“They compete with stock for pasture, reducing available pasture by 10 to 15 percent on some farms as stock avoid areas where wallabies have defecated.”
Around 10 to 12 Dama wallabies eat the same amount of pasture as one stock unit.
Wallabies can live for more than a decade and female wallabies can hold a fertilised embryo in ‘diapause’, so as soon as a joey becomes independent, the embryo will migrate to the pouch and continue developing.
Tackling the issue
The government allocated $27 million over five years (2019 to 2024) to address the wallaby issue in both the North Island and South Island. The funds which are administered by MPI, for the Bay of Plenty, Waikato, Canterbury and Otago Regional Councils. This is now an MPI budget giving some assurance of continued funding.
The programme, named Tipu Mātoro - Wallaby-free Aotearoa, is a national eradication programme and a partnership of central and local government agencies working with iwi, farmers, landowners and businesses.
Around 200,000 hectares are affected in the North Island, with a particularly dense population around Whakarewarewa Forest.
“We’re building a 1.2m high, 12km long wallaby fence from Whakarewarewa along State Highway 5 and then back inland to Lake Rotokakahi.
“Wallabies won’t attempt to jump the fence but will attempt to push through or under, hence the importance of the small gauge netting and a 300mm skirt laid flat along the ground.
BOPRC biosecurity officer Dale Williams manages contractors carrying out wallaby surveillance and control within the Bay of Plenty Region. Photo: Catherine Fry.
“By containing the wallabies within Whakarewarewa Forest we can begin eradicating wallaby populations south of SH5.”
Several landowners are farming within the containment area.
Highland Station has been in the Ford family since 1931, and has always been home for the current owner, John Ford. He is responsible for 1240 hectares, with 920 hectares effective for their beef stock and breeding ewes and the rest in covenanted QE II bush.
“Wallabies have been on our property for as long as we can remember. I learned to shoot around the age of nine and joined many wallaby shoots over the years.”
The wallabies live in the bush which was stock fenced when it was retired and covenanted, but there is no further funding available to build wallaby fencing. They come out into the pasture to feed at night.
“Most Dama wallabies are under 10kg, so it’s hard to shoot them with a .22 rifle from a distance,” says John.
“I allow contract companies to come in and carry out night shooting to reduce numbers on my land, and that helps with the overall effort to control them.”
The shy, nocturnal Dama wallaby is a major pest issue in the Rotorua area. Photo: Catherine Fry.
Dale confirms that this strategy is effective for lowering numbers but not eradication.
Thermal rifle scopes have been a huge advance for wallaby control allowing hunters to locate and shoot wallabies in complete darkness without startling them. John has previously seen 150 kills on his land over a two to three night period.
Bait stations are less effective for wallabies as possums will aggressively dominate access to the bait.
“An important part of the containment effort is finding out where the wallabies are. We have seven wallaby indicating dogs working with two contractors to locate wallabies and trail cameras to confirm the breeding status and delimiting populations.”
Dale’s ute is colourfully sign wrapped and there are large road signs around Rotorua encouraging people to report wallaby sightings to the regional councils.
The public are encouraged to go online at reportwallabies.nz, to report evidence of wallabies, either from droppings or foot prints, or visual sightings of them dead or alive.
Dale doesn’t beat around the bush regarding the measures that will be needed for eradication.
“The most effective control method in dense forest is aerial 1080 which will reduce the populations by 95 percent. Getting the final five percent to achieve eradication will probably come down to professional hunters using thermal imaging and dogs.”
For that approach to be successful, everyone in the containment area would need to be on the same page and in agreement with the often controversial measures required.