Catastrophe: Is NZ's debate about feral cat control too political?by Jenny Nicholls
We need more studies of New Zealand’s “subsidised predator” and native bush marauder.
The expert raids, on eggs rather than chickens, puzzled him so much he installed an infrared camera. He was shocked to see the culprit – not the stoat he was expecting, but six feral cats “of varying sizes”.
Warren and his wife, Colina, own a vast farm: 1400ha of rugged north Taranaki hill country, with ancient native bush covering ridges as far as the eye can see.
The, ahem, cat burglars have proven so difficult to catch that they are now eating more of the Neills’ eggs than the Neills are, although Warren reports his neighbour Bruce has caught four of the thieves in the past few weeks. Three of them were “huge”.
“We’ve given up on eggs,” Warren says mournfully. Colina now has to buy them at the supermarket, 60km away in New Plymouth.
The vision of giant cats with a taste for eggs marauding the New Zealand bush will darken the brow of any bird lover. But there are others who clearly think these groves are just the place for kitty. Incredibly, even though their farm is a 16km drive from SH3, the Neills recently watched a car stop and disgorge kittens at the bottom of their driveway. “We chased [the kittens]... but they got away,” says Warren.
Releasing cats into the bush is becoming more common here, he says. “People will drive all the way to the end of our road, 20km off the highway, and release cats there.”
I decide against sending the Neills a new book about cats by the US science writer Abigail Tucker: The Lion in the Living Room. It contains much about cats that is both fascinating and disturbing.
“[Unlike feral dogs], cats are doting mothers and unsurpassed breeders, both in and outside of the human sphere,” writes Tucker ominously. “Females reach sexual maturity at six months of age and thereafter reproduce more like rabbits than tigers – a key ecological advantage that’s in part a function of their small size and their hyped-up reproductive cycles. Five cats introduced to forbidding Marion Island (hardly a feline paradise) bore more than 2000 surviving descendants within 25 years.”
Warren has lived in north Taranaki all his life, and he reckons the cats are becoming a plague. At night he hears “nowhere near” the numbers of kiwi calls that he used to hear.
“Cats are devastating our wildlife,” he says. “Stoats aren’t helping, but in my opinion the cats are doing more harm than anything else in the bush.”
The Neills’ local paper is the Taranaki Daily News. Last September, it ran a harrowing story: “Little blue penguins are quivering with fear as feral cats invade their cosy homes.”
“Families” of feral cats were preying on Port Taranaki’s 20 nesting boxes, David Chadfield of Chaddy’s Charters told the paper. “I hear them at night and in the morning, there’s a massive amount of feathers everywhere.”
He suspected the outlook was bleak for the port’s penguins, despite efforts to catch the killers. “Cats are predators. Penguins are pretty good at defending themselves, but the cats will win in the end, I’d say.”
The urban boat owner echoes the words of the rural farmer. “I’ve seen cars tipping out bags of kittens in the area.”
The International Union for Conservation of Nature rates house cats as one of the world’s 100 worst invasive species. And it is their “special relationship” with humans, Tucker says, that helps make the cat such a formidable threat to wildlife.
“It’s not often that we knowingly promote the invasive plants and animals we transport around the world in ballast water or on the bottoms of our shoes. With cats, though, we load the dice in obvious ways: not only by introducing them to landscapes where they have no business being, but by feeding them generously, and taking them to the vet for shots, and allowing them to live in our houses.
“These advantages enable cats, as hunters, to defy basic laws of nature... in some places cats actually outnumber adult birds. That is a little like lions outnumbering wildebeests.”
In 2015, Australian Environment Minister Greg Hunt called cats “tsunamis of violence and death for Australia’s native species”. These apex predators have been implicated in the extinction of such a staggering range of Australian fauna that local councils are bringing in compulsory micro-chipping, desexing, household cat limits and long – in some cases around-the-clock – curfews.
Although New Zealand is fighting its own battle to save native fauna, research into feral cats seems minimal compared to other species. The University of Auckland’s James Russell, at the forefront of pest eradication research, says feral cats are under-studied “both because mustelids and rodents are seen as bigger threats, and because of a perceived ‘don’t go there’ view of cats as pests – it is too political”.
Russell, a rat expert, points out that the go-to eco defence of cats (they eat rats) is a poor one.
“The ‘diet equals regulation’ assumption is prolific, and frustrating, as it leads people to believe cats actually control rats,” he says. “To infer regulation, you need to know how many cats and rats there are, and how their population changes over time. Say you had one cat and 10,000 rats, and the cat ate only rats; the cat is not controlling rats.”
In fact, says, Russell, it may be the other way around. Rat numbers may be controlling feral cat numbers, in the same way beech seeds in a mast year control mice numbers. We don’t know.
New Zealand anti-cat lobbyist Gareth Morgan’s line – “it really feels like I’ve taken on the gun lobby” – resonates with US writer Tucker. As she points out, we like cats.
Even she likes cats.
“Cheetoh is my present pet, adopted from an upstate New York trailer park. His unusual size has caused the plumber to pause in wonder upon entering our living room... and it’s hard to believe this oversize croissant curled up at the end of my bed belongs to a species that has the capacity to upend an ecosystem.”
This was published in the November 2017 issue of North & South.