Catching a glimpse of Bambi through the trees might be a thrill for townie and deerstalker alike, but a growing population of hungry deer spells bad news for native flora and fauna – and Covid gets some of the blame
Outside the southern wilds, feral deer used to be a rare sight. Today, mobs are invading farms and the animals are grazing around roads and towns.
Some spread is coming from areas of protected native forest, where a build-up in numbers is causing serious harm. The pandemic is partly to blame, many say, as well as changes in Government regulations. Shifts in land use, too, are providing habitats that suit these attractive but destructive pests.
In healthy native forest, long-whiskered kiwi shuffle through forest-floor litter, eating bugs and seeds and probing their strange end-of-beak noses into soil to find worms and grubs. When deer have been there, however, that job becomes hard yakka. There’s not much to snuffle in and the ground can be dry and compacted.
Deer browse on undergrowth, first stripping the layer where fruit, insect life and leafy food sources thrive. They also munch through huge volumes of leaf litter on the forest floor – the rich organic matter home to native reptiles, snails and insects. When numbers get up, as in parts of Southland’s Hokonui Hills, what’s left behind is essentially bare roots and dirt, according to Department of Conservation (DoC) wild-animal project manager Dave Carlton.
Next, biodiversity suffers when only unpalatable species such as crown fern (piupiu) and pepper trees (horopito and kawakawa) are left after the broad mix of tastier plants has been gobbled up.
The destruction can go higher with mature trees dying from being ring-barked by hungry deer.
There would, of course, have been another large herbivore browsing here in the past, but the wide-ranging differences between moa and the introduced quadruped now at home in the extinct native bird’s habitat mean there’s little useful comparison, Carlton says.
In QEll we trust
The Queen Elizabeth II National Trust helps private landowners establish and care for special protection areas called covenants. Together with some covenants owned by the trust itself, nearly 5000 are registered, often on farms.
Otago has the largest area of QEII-covenanted land in New Zealand, covering about 65,000ha, and Southland boasts about 10,000ha. Kerri Lukis, the trust’s southern team leader of land protection, says two-thirds of Southland’s covenants are now being munched on by deer.
“Most native ecosystems are adversely affected. The level of damage ranges from obvious and severe – for example, a forest with no understorey and dying canopy trees – to subtler effects not always noticed by the casual observer such as loss of palatable herb species and reduced snow-tussock cover in high-altitude sites.”
Lukis says deer have a particular a liking for broadleaf (kāpuka or pāpāuma), māhoe, karamū and three-finger (orihou), but have also been known to plunder urban gardens and vegetable patches.
The trust is seeing deer multiplying and, in addition to other support, has secured Government Jobs for Nature funding for landowners with registered covenants that are being invaded.
There are also concerns, Lukis says, that deer and other feral animals are reducing the ability of forests to sequester carbon and that the battle to keep them out is proving difficult and expensive.
“Although we have landowners who are actively excluding and removing deer from covenants, rapid reinvasion can make people feel overwhelmed by the task of controlling deer. A landscape-wide approach, informed by public consultation, is needed to reduce reinvasion.”
In the trust’s latest newsletter, one Southlander reported considerable work being done to get rid of mobs of up to 50 deer eating swedes, fodder beet and kale crops. Another had removed 650 deer over an 18-month period.
Habitat suited to wild deer is plentiful and expanding in the south. Otago and Southland have more than 1,600,000ha of national park, most of it in Fiordland (1,200,000ha). Deer numbers have not grown significantly in the Mt Aspiring National Park region in the last decade, Carlton says, but in Fiordland populations are rising faster
In South Westland, too, deer are finding their way on to roads, and Gerry McSweeney, who owns Wilderness Lodge at Lake Moeraki, says the animals regularly wander up his driveway.
Spreading far and wide
Throughout the country, places previously free of the pests are being invaded.
Nine years ago, less than two-thirds of public conservation land was home to deer, goats, tahr or chamois. Now, that figure is at 82 percent, Carlton says. An area also seeing an uptick in deer numbers is New Zealand’s newest national park, Rakiura, which covers 85 percent of Stewart Island.
“Deer have expanded their range into the rural landscape in the past 20 years. They can now be found in many small reserves, covenants, river margins and other vegetation in many parts of Southland and Otago.”
Vetted businesses pay DoC for Wild Animal Recovery Operator (WARO) permits, costing about $2000 a year, to harvest venison from the parks. Carlton says this works well in Fiordland to reduce forest damage when the meat price is good.
He says the suspension of the commercial wild-venison industry in the early 2000s continues to contribute to the increases in deer numbers being seen in some places.
“When the industry recommenced a few years later, it was on a smaller scale. New Ministry for Primary Industry regulations mean that areas on the margins of forest parks often cannot be harvested.
“Often recreational hunters are denied access from private landowners to these same areas. This has been a significant factor in the build-up of deer on farm and forest margins.”
Central Otago helicopter pilot Doug Maxwell, who has worked in the pest-control and deer-recovery industries for 47 years, says restaurant demand for venison has fallen and other factors are also in play.
“The wild-deer numbers have quietly built up and a lot of it is to do with Covid. The feral-meat industry has had a bit of a hammering. Helicopters are the main method for controlling the numbers and it hasn’t been viable for a wee while.”
Maxwell says where DoC drops 1080 poison for possums, some deer end up being killed. But hunting is then curtailed because venison harvesters are not permitted to take deer within 2km of a poison drop zone.
Where regional councils use poisons like brodifacoum, no shooting is permitted for three years. And if a farmer with land adjoining native forest is reluctant to sign a declaration clearing the area for shooting, helicopters have to keep 2km from the boundary.
In some places – the North Island’s Ruahine Range, for example – that limits shooting to only about a third of a deer-infested forest.
“What’s happening is there are huge populations building up in that fringe area decimating the DoC area.”
Feds put pen to paper
In response to its members’ concerns, Federated Farmers has drafted a position paper about wild-deer issues that highlights the inconsistent venison market as a key factor in reduced shooting.
It says pandemic restrictions have played in the pest’s favour by cutting hunters’ access to shooting blocks during the March-to-April roar – when stags are competing for hinds with which to breed – and closing the border on foreign trophy hunters.
The paper also identifies an increase in deer habitat through such land-use changes as forestry conversions, manuka honey operations, the spread of wilding pines and retirement of pastoral hill country.
Some farmers traditionally guard their wild deer “stash” as a private hunting resource, a hangover from decades ago when numbers were low. Hunters, too, often follow long-established habits of targeting stags and leaving pregnant hinds.
“When deer were valued for venison recovery or live capture, landowners went to considerable lengths to protect and utilise populations on private land. Wild-deer numbers were very low in the 1980s and 90s, and many landowners were restrictive of hunting and access,” says the farmers’ lobby group.
Today, some landowners are shooting deer and leaving the carcasses to rot. Maxwell says helicopter “search and destroy” work for southern farmers is a measure he can not recall seeing before.
“It’s a waste but there are just not many factories processing feral deer at present because the market’s so bad. It will come right but it’s taking a while.”
Federated Farmers says others are rounding up wild animals to add to farmed stock. Deer fencing at a cost of tens of thousands of dollars is being erected to protect crops and tree seedlings.
It says hunting that is solely focused on reducing numbers is the most effective way of knocking back the pests. New Zealand’s recreational hunters, however, are also seen as valuable in helping curb damage.
Hunters to the rescue
Recreational shooters’ contribution is somewhat overlooked when compared with that of commercial hunting, but the numbers tell the story, according to Game Animal Council chairperson Grant Dodson.
“It is worth putting commercial hunting in context. Nationwide, it’s been estimated that recreational hunters kill about 135,000 deer a year, 132,000 other big-game animals, mostly pigs, and more than 230,000 goats. On the other hand, wild-animal recovery operations – commercial operators – are estimated to harvest 18,000 to 20,000 deer in an average year.”
Commercial operations focused on red deer are mostly in open country and have little effect on populations of other deer species, Dodson says.
The council, working with DoC and the Fiordland Wapiti Foundation, helped remove 250 female wapiti from sensitive parts of the southern New Zealand forest after low venison prices discouraged the area’s normally active commercial harvesters.
The council encourages hunters to help manage herd numbers by shooting hinds as well as the more sought-after stags.
“With deer being polygynous animals, the number of females has a big influence on future populations. Harvesting more hinds can also improve the quality of the herd, leading to a lower-density, high-quality herd that is both better for hunting and also helps protect native species.”
A deer in the headlights
DoC’s Carlton says motorists seeing deer near public roads is becoming more common in the south.
Stories of vehicles hitting animals are not uncommon and staff employed by Central Otago orchardist Raymond Paulin found out late last year what the results can be.
A group were travelling through the Pigroot in the Maniototo to the east coast on a fishing trip when a deer leapt in front of them.
“They were in a van and it was written off,” Paulin says. Luckily, no one was injured in the accident, evidently caused by a non-tagged wild deer rather than a farm escapee.
Waka Kotahi NZ Transport Agency reports there have been 43 accidents caused by deer on public roads in the past five years in Otago and Southland, and 98 nationally.
Near Queenstown, residents report hearing wild stags roaring most evenings near the busy road to Arrowtown.
Builder Hayden Coughlan lives near the foot of Coronet Peak and he and his flatmates have spotlit mobs of up to 30 red deer at night. He says passing motorists would be unaware of the animals, which emerge after dark. And in nearby Frankton, deer are often seen grazing in daylight along the banks of the Shotover River.
Long-time pest manager Ozzie Brown, of Naseby, says deer have become a common sight around townships, which worries Central Otago farmers.
“It’s the numbers that are around now and the damage they do, especially to crop paddocks in winter.” He says deer go wherever the feed is.
“They’re in certain areas in the Maniototo, such as around Naseby and Patearoa. I’ve lived in Naseby all my life and there are more deer around than I’ve ever seen. I see them from my home at times.
“I reckon in the night they walk up Naseby’s main street – I’m sure they do.”
Made with the support of the Public Interest Journalism Fund