Dunedin disease management boosts biodiversity

Date 17 October 2019

Close to 100 percent of possums on the flanks of Flagstaff in Dunedin have been removed by a recent OSPRI TBfree disease control operation.

Possums are the main carrier of TB infection between wildlife and livestock and need to be reduced to very low levels over multiple years to eradicate the disease, protect farming businesses and New Zealand’s primary industry exports.

TB-infected herds were found in the Mount Cargill TB Management Area in 2015, and a coordinated multi-year campaign of possum control is making progress towards OSPRI TB eradication goals. These are to eradicate TB in livestock by 2026 and in possums by 2040.

The operation at Flagstaff began in March is the first landscape-scale possum control to support TB eradication. A contracted crew of 20 professional possum control staff have removed over 4000 possums from the 2300-hectare area. An independent audit using 270 wax tags over seven nights has confirmed the success: only three bite marks were detected overall, and zero possums were detected on the Leith Valley side of Flagstaff.

OSPRI Southern South Island Programme Manager Eric Chagnon says “It’s really important for the region’s farmers, and for everyone in New Zealand, that we eradicate bovine TB from New Zealand.

“This is an excellent result for us and our contractor,” said Mr Chagnon. “While the work in Flagstaff has finished for this year, dogs should be kept on a lead in the area while warning signs are in position at access points.”

Further possum control work using traps and toxins around Mount Cargill, Signal Hill, Sullivans Dam and Bethune’s Gully will be repeated from 16 October. All possible measures are being taken to mitigate risks to pets while still performing an effective operation.

When the possum control starts, signage at all public tracks will carry clear instructions for recreational users.
Mr Chagnon says: “We’d like to thank landowners and members of the public for their cooperation while this important work is underway.”

OSPRI is a member of Predator Free Dunedin and the possum control is bringing huge benefits for Dunedin’s wildlife. After an evening walk up Bethune’s Gully, one walker recently told OSPRI staff that “the birdlife was incredible. Even in the pine trees, the tui and bellbirds were going nuts”.

When OSPRI achieves its goals to eradicate TB from livestock and possums, the low possum numbers throughout the 12,500-hectare PFD project area will be continued by the Halo Project. Operations Manager Jonah Kitto-Verhoef says “the low residual possum population we are now seeing in the wake of the incredible work from OSPRI and their contractors has well and truly opened the door for a predator-free future for Dunedin.

“The work being undertaken by our backyard possum trappers has confirmed a decrease in catches and the future for our local biodiversity is looking extremely bright.”

The collaboration between OSPRI and Predator Free Dunedin is captured in this video OSPRI Possum Control in Flagstaff.

Flagstaff strata

Flagstaff possum control trapping and bait stations have taken possum numbers close to zero.