Pest patrol – dogs enlisted for pest-free Banks Peninsula success

Pest Free Banks Peninsula are working to protect the biodiversity of Banks Peninsula Te Pātaka o Rākaihautū through the eradication of all animal pests by 2050.

For a piece of land without the water border of an island sanctuary or the predator-proof fence of a land sanctuary, it is a bold goal, first laid out in 2016 in the 2050 Ecological Vision for Banks Peninsula developed by the Banks Peninsula Conservation Trust in conjunction with the local community. Two years later, Pest Free Banks Peninsula was formerly established by 14 founding signatories, including local councils, rūnanga and the Department of Conservation.

“We are amongst some others trying to do it for the first time, so we are all learning together,” PFBP project manager Sarah Wilson tells Frank Film. “Nobody knows how to do this.”

Banks Peninsula Te Pātaka o Rākaihautū is an ancient volcanic landscape, covering around 115,000 hectares of farmland, pockets of native bush, plantation forests, cliffs and beaches encroaching on the edges of Ōtautahi Christchurch. It is a unique landscape rich with native flora and fauna including tūī, ruru (morepork), pīwakawaka (fantail), kororā (white flippered little blue penguin), hoiho (yellow-eyed penguin, tītī (sooty shearwater), waterfowl, jewelled geckos and spotted skinks. At least six plant species and more than 60 invertebrate species, including the rare beaked moss moth, Gadira leucophthalma, do not exist anywhere else in the world. 

Threatening this biodiversity are invasive populations of rats, mice, stoats, ferrets, weasels, hedgehogs, feral cats and an estimated 460,000 possums.

“When you look at possums and rats and stoats and everything else put together, the damage they do to the whole ecosystem is pretty significant,” says PFBP operations manager Tim Sjoberg. “If you start reducing one native species versus another then you are really throwing the balance of the whole ecosystem out of whack.”
But the peninsula’s near-island topography is an advantage, allowing the eradication programme to move steadily from the coastal edges on the east and south towards the west, hopefully without losing advances to reinfestation.

To work within available funds, half of which comes from Government company Predator Free 2050 Ltd, it is beginning in two elimination sites.
The appropriately named Wildside Project covers 23,000 hectares of steep gullies and towering sea cliffs on the south eastern corner of the peninsula. While aimed at feral cats, ferrets, stoats and weasels, its primary target is possums. Sjoberg takes Frank Film through the stunning beauty of the DOC-owned Nikau Palm Gully, pointing out trees etched with claw marks and saplings stripped of foliage. “The damage they do to the forest structure by eating the most palatable species, the absolute appetite for invertebrates and everything else – these guys have an impact on every cycle of the ecosystem.”

The eradication programme here relies on self-resetting battery powered traps in more inaccessible areas, over 90 live capture traps laid on roadsides and in public parks and backyards and poison bait stations using encapsulated cyanide.

Unlike more remote eco-sanctuaries around the country, care is required around private dwellings, public walking tracks and water-take areas but in setting traps, checking trap lines and monitoring the area for reinvasion, community support, says Sjoberg, is vital.

“We are working in people’s backyards, on their farms – there is some public land but the bulk is private land so having that buy-in from the community is absolutely critical. In this country if you walk away from it without doing any control, you’ve lost all that work, all that mahi, you’ve done – they’ll be back.”

Sjoberg estimates the programme has already killed around 4000 possums over the last two years; cameras in 20 sites around this remote area show a dramatic decrease in possum numbers in the last six months alone.

“A few more to go but we are learning every day and we are accelerating every day."

"If we are valued by the community, and we undertake this safely and professionally, then I am confident funding will come and we will be able to scale up and work across that landscape.”

Credits:

Producer/Director/Cameraman/Interviewer: Gerard Smyth
Editor: Oliver Dawe
Writer: Sally Blundell
Production Manager: Jo Ffitch
Sound Design/Mix: Chris Sinclair