Big read: How deer are destroying Fiordland's forest

Experienced back country locals are reporting sightings of emaciated red deer in Fiordland National Park, but say it is a sign the hardy, invasive mammals are prevalent rather than dying out. Deer get thin when their numbers increase and there is less food — palatable, native foliage — to go around. If allowed to breed unchecked, deer can increase by around 30% a year, doubling within three years. Conservationists say rapidly-breeding deer in Fiordland are eating and trampling vast tracts of the 1.2 million-hectare park’s precious forest and alpine plants, risking ecological collapse and loss of a vital biodiversity haven and carbon bank. One leading forest ecologist describes the state of Fiordland’s Kepler forest as “buggered” due to deer and has written a paper calling for a national strategy to protect all conservation land from exploding deer numbers before it is too late. There are conflicting voices in the Fiordland community about the urgency and what needs to be done. One prominent and experienced commercial helicopter pilot, who has flown many missions with hunters shooting deer from the sky, says the forest can cope with a managed deer herd. As commercial hunting for the wild venison industry is increasing, “it won’t take long” for the worst of the problem to be knocked back. In around a sixth of the park, the government decreed last month that a herd of wapiti — a large deer prized by recreational hunters — should be given special status and allowed to be managed by a charitable foundation that promotes hunting, but also undertakes conservation, including killing red deer. Volunteers working for other Fiordland conservation organisations are often careful to commend the hunter-led efforts in the absence of a conservation budget to cull deer at scale. However, they stress the urgency of rescuing “devastated” forest, and point to offshore islands where deer have been eradicated and the bush is dense and native birds thrive. The number of deer on the mainland are unclear. Department of Conservation (Doc) national wild animals manager Mike Perry said the impact of deer in Fiordland was across a “very large landscape”. The Doc budget for deer control was “finite” — hunter-led efforts were “substantial contributions”, but the forest was still suffering, he said. “It’s fair to say current resources are not sufficient to reduce deer impacts simultaneously across the entirety of [the park] at the intensity required to achieve strong ecosystem health”. Ken TustinRed deer photographed by a remote camera at Herrick Creek near Wet Jacket Arm, Fiordland. Photo: Ken Tustin For many tourists, the problem is likely out of sight and out of mind. The forest, at large, looks green. Forest & Bird volunteer Ruth Shaw has transformed her Manapouri garden into a mini native forest, but worries that planting initiatives can distract even local people from the unobserved, giant problem in the park on the other side of the lake. “Deer numbers have ballooned, [they] are eating undergrowth and causing a dying forest. It is as simple as that, but people can’t see it. “It’s just so infuriating.” [Missing Credit]Forest & Bird volunteer Ruth Shaw of Manapouri is concerned about the state of Fiordland forest due to deer eat out. Photo: Mary Williams Now, concerned locals like Ms Shaw have been vindicated by University of Canterbury emeritus ecology professor David Norton in his recent paper “Deer in the headlights — sleepwalking our way to a native forest catastrophe’’. He explains deer browsing means a lack of replacement trees. Deer, combined with climate change, also impair mature trees’ ability to survive or even drop seeds that thrive. Less organic litter, unseasonal droughts and compaction by deer hooves can lead to thinner, drier, hotter, soils providing less moisture and nutrition to trees’ lateral feeding roots, which lie in the top 10cm of soil. “The tree becomes less healthy, can’t reproduce as well and, at the extreme, will die.” A strategic approach was urgently needed to map forest values at landscape scale and work to protect them at appropriate levels, Prof Norton said. Hunters could possibly have deer management responsibilities in some less sensitive areas areas, but it was “cart before the horse” to declare a special herd in a particular place before ecological mapping. He was “shocked” at the state of the beech and podocarp forest when he recently tramped Fiordland’s Kepler Track. “I thought it would be better, but it wasn’t. There is a lack of awareness of the roles of old growth forests — and what they should look like. “It’s beautiful, but buggered.” He flags a lack of cash as “the single biggest challenge to control deer. How do we fund it?” [Missing Credit]Professor David Norton is calling for a national strategy to determine the fate of deer to save the forest. Photo: Al Guthrie/Pure Advantage Funding is a battle being fought at the frontline by community-led conservation groups reliant on fundraising and working in disparate parts of the park. Many of their efforts are understandably on islands, where deer can be eliminated quickly. Conservation efforts can then focus on continually eliminating invasive predators that can also swim, such as stoats, and on reintroducing and nurturing native birds. The approach is limited in scale but enables monitoring that evidences the outcomes of forest protection. On 262ha Pomona Island, five deer were removed by the Pomona Island Charitable Trust when established in 2005. Vegetation surveys in marked plots, undertaken before deer removal and 15 years later, found plant species that deer love to eat, including fuchsia and broadleaf, were initially absent then returning. Trust chairman John Whitehead said he was “amazed” at the difference. “To get back to something pristine you have to take deer numbers back to virtually nothing. You get this moving base line and people think, ‘oh, look at these lovely beech trees and crown fern’, but crown fern is unpalatable to deer and that is why it is still there.” [Missing Credit]John Whitehead, chair of the Pomona Island Charitable Trust, says eradication of deer from the island enabled palable plant species to return. Photo: Mary Williams Coal Island Trust chairman Ali King tells a similar story. In 2004, when the trust was set up, about 30 deer were shot on the 1163ha island. Mice, which eat seeds and birds, were also exterminated. Now, the flightless kakapo had been reintroduced to rejuvenated forest and the difference was “outstanding”, Mr King said. “When the deer were there you could see through trees for miles, the undergrowth was so eaten out. You didn’t have to worry about cutting tracks. “Now, we need teams to recut tracks because they get overgrown so quickly. It is like chalk and cheese between the mainland and Coal Island.” Mr King is talking about the Puysegur peninsula. “There is an overpopulation of deer there. Their running tracks are boggy trails and the undergrowth is devastated. “The numbers [of deer] have exploded since Covid … The only answer is helicopter suppression, like in the 1970s, but it is very expensive.” [Missing Credit]Coal Island Trust chair Ali King says the difference between bush on the island - where deer are eradicated - and on the deer infested mainland is "chalk and cheese". Photo: Mary Williams During the 1970s, the so-called “deer wars’’ happened, with extensive shooting of Fiordland deer from helicopters for a wildly profitable venison export market. There were many tragic crashes and eventually the price bubble burst. It was followed by a brief period of live capture for the emerging deer farm industry, when there were about a dozen helicopters working out of Te Anau and a hind could fetch about $3000. However, since then, commercial shooting has been mixed as wholesale carcass prices have gone up and down. Long-time Fiordland helicopter pilot Kim Hollows takes a positive stance. The economics of commercial shooting from the sky — known as wild animal recovery operations (Waro) — is “borderline” at present, he says, partly due to the cost of fuel and aircraft componentry, but an improving deer market means Waro operators are getting “close” to making good money again. Three or four helicopters are recovering deer part time, and he says Waro will be on the “right side of history … it won’t take long for deer numbers to get back to a manageable level. That happens real quick”. On an average day — which is weather-dependent — Mr Hollows might make two trips, hauling out about 10 deer each time. He agrees with a long-held view deer numbers can be kept stable in the park by removing about 5000 deer every year. “That keeps a sustainable crop, a healthy herd and healthy forest … it won’t take long to regenerate, I have seen this before.” He flags a challenge at the western edge of the park — the cost of flying helicopters there. It is also not possible to hunt after a Doc aerial 1080 poison drop, which has happened in a fifth of the park since 2023 and results in notable deer bi-kill. There is a delay of four to nine months before hunting can resume. [Missing Credit][object Object] The number of deer being shot in recent years in Fiordland is likely below 5000 each year. Doc says 2366 deer were removed last year by commercial operators plus about 1100 from the 190,000ha wapiti area managed by the Fiordland Wapiti Foundation. Foundation general manager Roy Sloan said two decades of killing red deer in the wapiti area, and managing the size of the wapiti herd, had “proven steady deer management [was] the only way forward’’ and they should be taking notice. [Missing Credit]Wapiti are now in a Herd of Special Interest (HOSI) that is protected in Fiordland National Park for hunting. Photo: Paul Peychers There is also some Doc-led deer culling — including ground shooting — on Fiordland islands and on the mainland around the Murchison mountains, where the flightless takahe is protected, and around the deer-free Cleddau Valley, next to Milford Sound. Mr Perry said Doc-led efforts were focused where reducing browsing pressure would “deliver the greatest biodiversity benefits”. However, he adds that in “many” ecosystems, where browser pressure is high and sustained, they were “likely to see vegetation structural and compositional changes in the long term” that would be detrimental to ecosystem health. [Missing Credit][object Object] Aaron Russ, co-owner of Heritage Expeditions, which operates awareness-raising trips to the outer-reaches of Fiordland, says many New Zealanders may not appreciate that Fiordland is not “a pristine, unspoiled wilderness”. He is concerned about the level of political will to fund more pest control and calls on Doc to seek impactful opportunities in partnership with community stakeholders. “The Fiordland Wapiti Foundation have their motivations, but equally they are doing more for deer control in the wapiti area than I think any other conservation group in Fiordland is doing over an equivalent area.” Established in 2014, the Hollyford Conservation Trust is another community-led conservation effort on the mainland seeking to restore 18,000 hectares at the northern end of the park. Its work includes killing invasive predators such as stoats and possums and manager Lindsay Wilson describes biodiversity outcomes as “phenomenal”. “It is so satisfying to enable visitors to hear the return of the dawn chorus.” However, he doesn’t hold back about the need to tackle deer. “Ultimately there is a need for control work that goes well beyond what recreational hunters can do … It’s definitely time to begin the conversation around how we can best ensure the protection of our vulnerable plant species. Any deer management work will need to be focused, well considered and sustained.” He rams home a need to get all factions on board. “Long-term solutions need to gain the support of stakeholders including iwi and the hunting community.” [Missing Credit]Ferns, but few other plants or saplings, on the edge of the Kepler forest in Fiordland, indicating deer browsing. Photo: Mary Williams The North Island’s forested Raukūmara range is often called the Fiordland of the North and provides a case study of funded, landscape-scale deer control, beyond Fiordland’s politics. Thanks to $34.4m funding from the former Labour government’s Jobs for Nature programme, deer eradication efforts led by iwi conservation organisation Raukūmara Pae Maunga have removed 2400 deer annually from 73,000ha of the range over the past five years. The deer shot per hectare is higher than the toll in the wapiti area. The figures are incomparable — achieved in different terrains with different deer populations — but emphasise the effort. Aerial shooting is followed by ground shooting and concerted fundraising means work is continuing. Raukūmara Pae governor Ora Barlow speaks for forest health, and indigenous rights to a healthy forest that sustains taonga. She says Doc budget prioritisation is understandable, but concerning. There is a need to know how much of New Zealand’s conservation estate is being maintained below ecologically acceptable deer densities, what it would cost to address it and what happens to the landscape if control does not occur. “The question is whether we’ve resourced the response at anything like the scale of the problem. Prioritisation makes sense when resources are limited, but we need to ask what happens when the thing being rationed is the protection of natural infrastructure. “You can save a high-value biodiversity site, but if the forest, soils, water systems and regenerative capacity around it are progressively deteriorating, eventually you’re managing islands inside a collapsing system.” mary.williams@odt.co.nz