History is repeating itself across New Zealand’s back country and farms but this time there are no good keen men being handed rifles and rations and sent to sort it out.
Skinny feral deer were culled in their thousands between the 1930s and 1950s after ballooning populations led to wide-scale wipe-outs of palatable vegetation in native forests.
What really saved the day however, according to a new research paper, was venison and live deer recovery using helicopters, which drastically reduced numbers and gave native vegetation a 30-year recovery window.
That reprieve is now far in the rear vision mirror, the University of Canterbury study shows, and observing the decimated state of some of New Zealand’s native forest today inspires only one word – bugger!
Deer and other feral pests have again reached crisis point, with a documented escalation in numbers in the past two years, despite more control work being done, according to Federated Farmers.
A possum plague has hit the southern coast, and sheep and beef farmers across New Zealand are paying cullers and doing extra hours themselves, while still watching their crops get eaten by deer.
In the Catlins the evidence is clear to see in broad daylight out the truck window, according to farmer Rachel Napier: mobs of feral deer grazing in paddocks, pig rooting along verges, trashed vegetation, damaged fences and plenty of roadkill possums.
The proof is on paper too; in the new study led by Professor David Norton titled ‘Deer in the Headlights; sleepwalking our way to a native forest catastrophe‘, co-authored by Peter Bellingham and Sarah Richardson, it documents feral deer populations rising largely unchecked over much of the country since 1995, most rapidly in the past 10 years.
The relentless fight to protect farm and forest from destructive pests is taking its toll on residents in the Catlins, says farmer Rachel Napier, pictured with husband Craig.
Supplied / Newsroom
The majority of these animals are uncontrolled, the paper says, other than by recreational hunting and a few wild animal recovery operations which have made no difference to their population growth curves.
A graph shows the current deer population in an alarming trajectory, a repeat of the pattern which inspired the 1930s Government intervention, and author Barry Crump’s tales of the Forestry Service cullers in his novel A Good Keen Man.
Norton’s research frames the ungulate horror story in its modern context, highlighting a few key plot twists that no one really wants to talk about.
He points out that when the historical mobs of red and fallow deer were bashing the bush to bits it was the first time it had happened and other pests were yet to establish in anywhere near their current numbers.
The forest and its inhabitants were more robust and better able to recover once deer numbers reduced. Today with fellow pests like pigs, goats and possums in larger numbers, the bush is being attacked on several fronts at once.
The result is that plants’ “successional pathways” are becoming so altered by deer browsing (reds) and grazing (fallow) and other pests, that different species become dominant.
Regenerating forests will be “compositionally dissimilar” to what was there before and that’s potentially very bad news if you’re a kererū, tui, kiwi or any other bird dependent on a less-resilient food source.
Preventing birdlife getting eaten is the key motivator for huge effort being made by the country’s prolific predator trappers but protecting avian food sources from browsers is a less-accessible activity for backyarders, and therefore less fashionable. Norton’s study says certain fruits and nectars are at risk of disappearing as well as invertebrates that help sustain birdlife. Nesting sites also become harder to find as canopy collapse caused by deer kills mature trees.
Impacts on birdlife from ungulates is already documented in similar scenarios overseas, the paper states, and is “highly likely” to occur here if that ominous black line on the curve continues as expected.
Climate change is also exacerbating the effects of erosion and soil loss which occurs through denuded, pugged and rooted-up ground. Norton believes the combined effects of climate change and deer could be “catastrophic”, and priority should be given to identifying key biodiversity areas and catchments that are critical for providing climate change resilience first and focusing control work there.
On the positive side is technology – trail cameras, AI-powered traps and ever-advancing drone capabilities. Thermal scopes and all-terrain vehicles put modern hunters in the right place quicker than their foot-bound, daylight-dependent predecessors.
But without sufficient funds and regulations to ensure pest control happens in a coordinated, ongoing way, technology cannot head off a crisis.
In the Catlins, Rachel Napier says pest numbers had “exploded”, especially possums, pigs and deer. Impacts such as farm and forest damage were “by far the worst” she had seen since arriving in Tahakopa 17 years ago.
“There’s 50,000 hectares of public conservation land, and the problem is in there. There’s no maintenance being done apart from in little pockets. It’s the damage we’re seeing to our native bush and to our bats and birds … all our little precious critters that we should be looking after.”
She worries about the physical and mental strain the issue is putting on people, largely caused by the relentless reinvasions that quickly undo daily efforts in control work.
“It’s not just the financial costs, it’s the physical toll. And it always plays on your mind. My husband will get up at four o’clock in the morning, sometimes to go out. My son also goes out hunting, then they’ve got to go out on the farm all day. But then we’re just constantly getting reinfected. It feels frustrating, like you’re not getting ahead, we’re losing a battle.”
The cost of ammunition alone meant missing your target or shooting a few extra pigs on the way home was not an option.
“You’re looking at over four dollars for a decent-sized bullet to go out after a deer or a pig. It’s a bigger calibre than a.22 because they’re a reasonable-sized animal so that adds up.”
As a result of a letter Napier wrote to the Otago Regional Council in her role as deputy chair of community group Catlins Coast Inc, a meeting is now being set up to discuss the issue with the Department of Conservation.
The pest problem message was being received “loud and clear,” across Otago, councillor Andrew Noone told fellow councillors, when reviewing Napier’s letter.
Noone is leading a 10-year review of the council’s regional pest management plan but this won’t become operational until mid-2028. He was aware of issues throughout Otago involving impacts on pasture, crops, forestry and native vegetation. Concerns had also been raised about feral deer – which do not have pest status in Otago – becoming a hazard on roads.
“As a farm kid growing up in East Otago I never saw feral deer on our property, it’s not uncommon now to see mobs of 10 to 15 roaming the hills.”
Noone says classifying them as a pest in the new plan would require a biosecurity impact assessment and a cost-benefit analysis, both being required by the Biosecurity Act to justify inclusion. In addition, a national strategy was essential.
“There’s no doubt national direction or strategy is needed, this would inform and impose requirements regional councils would need to implement. It’s the sort of grunt that’s crucial to enable better control and management of feral deer.”
He says the current review of the Biosecurity Act, which rules on long-term pest animal management, would include submissions, then a select committee process and this was not due to be debated in Parliament until late next year.
Napier hopes help will come sooner than that for the Catlins Biodiversity Group. It was formed four years ago by farmers in the Owaka Valley, alarmed at the huge possum numbers they were seeing and the damage to native bush.
She believes the solution is direct investment in control work on Public Conservation Land, with an emphasis on action rather than more monitoring, research and trials.
“We believe basic, repetitive pest control for public land needs to be funded by central Government. It would seem New Zealand’s current management of pest control for public land has for many decades involved a lot of talking, with little bursts of action but long periods of nothing.”
Feral deer population trends (black line) since their introduction in the mid-to-late 1800s to today, and beyond. The dotted line indicates estimated populations without human intervention.
Deer in the Headlights/David Norton
She said there was no question of the need for the work as the evidence was plain to see.
“We know exactly what’s where, we don’t need to go too silly with the monitoring. A lot of time and energy gets spent focusing too much on getting the perfect plan. We’ll drive the road at night or day, you either see dead possums, or you’ll see live possums at night. The pig rooting you can see along the roadsides or just look over a boundary fence … here, in our valley you can see deer out grazing in numbers of up to 20 or 30 during the day.”
In the Owaka Valley, dairy farmer Cody Hartvigsen says one neighbour was taking around 2000 possums off their farm a year, and annual pest-related spending on larger properties was estimated at around $20,000.
Tallies from bait stations were reaching previously unheard-of levels – the highest recorded being 21 possums killed in one night at a single southern rātā tree.
“It’s what they’re doing to the forest, like the rātā, they love it. And up behind me, there’s a hill called Cedar Hill and all the rātā’s dead. It’s DoC land and it’s one hundred percent possums doing it, one hundred percent.”
Hartvigsen says deer were also a serious problem on some farms in the Owaka Valley, with mixed successes being seen from spraying repellent on crops.
“I’m in the Otago South Rivercare Group and we’ve done a trial with deer repellent. You’ve got to chase the deer off it for a start and then they just keep away. The farm that we did it on, they said if it didn’t work, they wouldn’t be putting in winter crop because it’s not worth their while. They just get decimated by deer, they’ve got bush all around them.”
The threat of a tuberculosis outbreak among dairy and beef cattle – the disease being carried by deer, pigs and possums – was a growing worry, Hartvigsen said.
Minister for Conservation Tama Potaka’s announcement on 25 August of an extra $9.7m in Government funding for feral deer and goat control has been welcomed but will be of no comfort to the Catlins community. The International Visitor Conservation and Tourism Levy funds are already tagged for spending across six other pest priority areas, spread over four years.
“Great, but a drop in the ocean in terms of what’s required,” according to professor Norton.
John Walsh, Biosecurity New Zealand director of pest management, told Newsroom a range of work was underway to address pest, and particularly deer, issues.
“The Feral Browsing Animal Programme was set up to support farmers and growers. The development of the national wild animal framework directed by ministers is also an acknowledgement of the growing urgency of the problem and the need for a coordinated response.”
He says work being done under the programme, such as a cost-benefit analysis, along with the development of the national wild animal framework, were “building blocks” for more effective management.
“We will be looking at regulatory settings to establish if there are barriers and what could be done, such as the review of the Biosecurity Act and National Policy Statement on Pest Management, which sets ‘good neighbour rules’, putting responsibility on landowners to prevent pest spread to their neighbours.”
In August Federated Farmers reported nine out of 10 farms from their 660-farm nationwide survey were doing control work, with nearly a third having to reduce stocking rates due to pest issues. Around half of those surveyed were being helped by recreational hunters who played an important but not pivotal role.
“We are not going to shoot our way out of this problem one weekend at a time,” Federated Farmers spokesperson Richard Dawkins said.
Meanwhile in the Tahakopa Valley where Napier says cars are now hitting feral pigs on the roads, the impacts continue daily on farms. Watching the native bush getting decimated, however, was perhaps taking a bigger toll on residents.
“It’s sad for conservation … for our public land to be in that state. The deer in many places have grazed as far as they can reach standing on their hind legs and they’re taking out all the seedlings and then the pigs are coming along behind and rooting up the ground. And then, of course, we’ve also got the possums eating whatever they feel like; it’s a vicious circle.”
– This article was originally published on Newsroom.