The view across Lake Okareka to the bush-clad hills on the northeastern shoreline is serene – but this could soon change drastically thanks to the havoc wreaked by wallabies, possums and rats.
Until recently, the 80ha Okareka Scenic Reserve near the DOC campground has never had pest control. The steep terrain is challenging and difficult to access, explains Lake Okareka Community Association (LOCA) spokesman Colin Jackson.
“But once you get in there, it’s really obvious that possums are browsing the tops of trees and wallabies are grazing the understory of the native bush. Rats, mice, mustelids and feral cats are clearly taking out bird life because the birdsong is really quiet in there. There’s not a lot going on.
“Because of the density of these pests, the risk is the native bush will collapse because there’s no saplings. There’s no young natives coming through to replace the ones that, once they get to end of life, are going to fall. So unless something’s done, an area that is impressive to look at from the other side of the lake now, is at serious risk of disappearing.”
To prevent this deterioration, LOCA installed 110 kill traps 12 months ago to help bring predator numbers down. Recent monitoring shows a 50 per cent reduction has been achieved so far, but eradication is the ultimate goal.
“It’s easy to have a go at knocking pests back. But over time, the cost of control is significantly more than the cost of eradication. So we would like to eradicate wallabies from this area of reserve,” Colin says.
LOCA’s long-term wish is to create a sanctuary safe enough for bird life to flourish and kiwi to be released. This will require a $200,000 wallaby-proof fence and ongoing pest control efforts. But before this is achievable, a feasibility study must first be carried out.
BayTrust has granted LOCA $25,000 towards the feasibility stage of their sanctuary restoration project. The money will pay for a study to determine whether the release of kiwi or other native bird species is possible – and if so, when.
“We’ve got three sides to fence and then there’s the water along the lake edge. But before we can consider using this reserve as a native bird release site, we need to understand what the requirements are, what that means, and what level of pest control we are going to need.”
BayTrust’s grant will also help pay for further pest control monitoring to measure progress. “There are still plenty of rats out there. When we started there would have been 100% saturation of monitoring tunnels. We’re down to 50% now but if we are to release native birds, we’ll probably need to have that down under 5%.
“The issue is the area will keep being re-invaded. It’s not just a matter of clearing pests out and that’s it. So the other thing we will do with this funding is apply for a license to use toxins in bait stations just prior to birds fledging. If we can drop pest numbers at a time when birds are really vulnerable, that really helps get bird numbers up.”
Colin and his fellow LOCA volunteers are excited at the prospect of helping the bush recover and birdlife to thrive once again. If the feasibility study shows native bird release is possible on site, the group’s ambition is to achieve this within five or so years. “It can take some time to get pest numbers down so five years would be a great goal.”
Going forward, a wallaby-proof fence and use of bait stations and drones are tools that could be used to eradicate pests from this iconic area.
“The grant from BayTrust will enable us to complete stage two of our project – improve our pest control, get some monitoring happening, and get a study done to see how far we can go. We are thankful for their support.”