WARNING: This post contains images and descriptions of pest animal trapping. If this distresses you, please do not read on.
When the chunk of land that became the islands of New Zealand broke away from the great southern continent of Gondwana seventy million years ago, it wasn’t just the nasty beasties that stayed on the larger portion – the only mammal native to these shores is a tiny bat (ironically voted bird of the year in 2021 – best not to ask). With a lack of predatory mammals, birds evolved differently from those in other areas of the world, many of them becoming flightless, all of them without the survival skills required to live alongside animals such as rats, cats, dogs, stoats, possums, goats etc. You can imagine what happened when two-legged mammals arrived and brought their four-legged friends with them: carnage.
Many of the birds endemic to New Zealand are already extinct; many are close to it and only survive in enclosures where predators are kept out by high fences, or on small islands where the sea forms the barrier. Otherwise the forests are scattered with traps in an effort to try and control introduced mammals. While tree roots are ready to trip the unwary hiker and overhanging branches swoop to try and decapitate an inattentive walker, small wooden boxes await smaller pests. These traps don’t bait themselves and an army of volunteers regularly tramps into the bush to check them, remove dead bodies and re-bait them. Our neighbour, Adrian, is such a volunteer, tramping up and down a section of the Mangawhero River every few weeks with his wife, Liz. We tagged along one day last week.
We weren’t sure what to expect but we knew one thing – this wouldn’t be an easy walk. I’d already expressed misgivings about being under the sun for a few hours (we were in the middle of a serious heatwave) and Adrian had assured me we would be within the forest, a fact I should have realised as the creatures we were tracking prefer the shelter of trees to the openness of the mountainside. We parked in a small layby next to what seemed impenetrable bush until Adrian moved a few leaves and there was a small opening, just enough to squeeze through. The ground, hidden somewhere beneath a thick layer of green, dropped away steeply. Adrian tripped lightly down it; Liz followed a little more carefully; Neil and I stepped and slipped like a couple of creatures whose legs aren’t connected to their bodies.
We caught up with them at the bottom, near the riverbank, as they bent over the first trap. Adrian unscrewed the lid and revealed the first prey of the day: a rat. Wedging a screwdriver into the top of the trap so it wouldn’t rob him of his hand, he picked up the carcass by its tail and hurled it into the bush, then removed unused old bait and popped in a piece of fresh rabbit meat. I say fresh – it had been in their freezer for weeks and Liz, uncomfortable with having it sitting next to the ice cream, was glad to see it finally out of there and fulfilling its destiny. I made a mental note to check the menu before accepting a dinner invitation.
We trailed the experts upstream, following pink markers nailed to trees and a vague suggestion of a path on the ground. Sometimes there wasn’t even that and we pushed our way through low scratchy ferns and scrambled up and down steep banks, across side streams and around fallen trees. The phone in Liz’s hand emitted an alert when we were near a trap, although Adrian was often already there, screwdriver poised. Neil even donned gloves to help out. I declined, not from squeamishness of possible dead bodies, but those traps looked lethal and I’m fond of my hands.
The tree cover provided shelter from the fierce heat of the sun but even so the temperature reached 22C by 10am. A slight breeze ruffled the canopy but didn’t reach us. Brighter patches of green marked where a larger tree had fallen at some time, allowing the sun in and plants, mainly ferns, to flourish. The usual woody mushroom smell of the forest floor was replaced by a fresher, almost cut-grass, tang, an underlying aroma of fruit fermenting in the heat. The chatter of cicadas vibrated around us, interspersed occasionally by the call of a tui or a shining cuckoo, the whoop of an otherwise silent kereru’s wings. The river bubbled over pebbles and small rocks, swooshed around large boulders. We crossed it where it was wide and shallow and paused at its edge for a snack.
After the initial success our booty dwindled, only one more rat caught, this one in a possum trap, a newer device that should eject its prey and reset itself. It took a bit of working out, and a battery replacement, before the rat was out of the way and the trap reset to continue its work. While Neil and Adrian went to check the last trap, Liz and I paused by the small ridge they had just surmounted. A shadow caught my eye, a piwakawaka flitting amongst the branches, showing off the fan of its tail that gives it its European name. Another movement and a toutouwai (robin) landed on a twig less than a metre away. Liz and I fell silent and I scraped my pole along the ground to entice it to search for disturbed insects. But it wasn’t interested, instead flying off after another that had invaded its territory. I hope that, thanks to volunteers like Adrian and Liz, a fellow bird is the only interloper it has to worry about.
Note: I love all animals. But mammals, for example the hedgehog, that are beloved in my home country of Britain are introduced pests here. I still find it hard to think of Mrs Tiggywinkle and her ilk as nasty beasties we need to get rid of. It’s part of the struggle of living with a foot in two worlds.