Deer, oh dear!

By Alina Suchanski

Reading time: 14 minutes

New Zealand has a history of introducing species to its ecosystems that have led to ecological disasters. We all know about the rats, rabbits, stoats, ferrets, and possums, but how did the introduction of deer impact on our environment? Alina Suchanski writes about one of the lesser-known environmental mistakes committed in this country.

Young tānekaha (celery pine) trees with ringbarked trunks and dead leaves attracted my attention on a recent hike in the Fiordland National Park (FNP). Knowing that the word ‘tānekaha’ in Māori means ‘strong man’, I wondered why these young trees have died well before reaching maturity.

The culprits: deer. Beautiful and graceful, these animals have been causing huge damage to our native forests and farmland since their introduction in the late 19th century.

By Alina Suchanski

Reading time: 14 minutes

New Zealand has a history of introducing species to its ecosystems that have led to ecological disasters. We all know about the rats, rabbits, stoats, ferrets, and possums, but how did the introduction of deer impact on our environment? Alina Suchanski writes about one of the lesser-known environmental mistakes committed in this country.

Young tānekaha (celery pine) trees with ringbarked trunks and dead leaves attracted my attention on a recent hike in the Fiordland National Park (FNP). Knowing that the word ‘tānekaha’ in Māori means ‘strong man’, I wondered why these young trees have died well before reaching maturity.

The culprits: deer. Beautiful and graceful, these animals have been causing huge damage to our native forests and farmland since their introduction in the late 19th century.

With full support of the government, many different species of plants and animals – mainly from Europe – were introduced to New Zealand by acclimatisation societies established by European colonists from the 1860s onwards, in order to help settlers feel more at home in their new country. At that time, there was no understanding of the impact this would have on the native flora and fauna.

The first New Zealand acclimatisation society was established in Auckland in 1861. Many others followed, including Wanganui and Nelson (1863), Otago and Canterbury (1864), and Wellington (1871). In 1903 they combined to form the New Zealand Acclimatisation Society.

Animal imports included brown trout, rainbow trout, deer, mallard ducks, Canada geese, hares, quails, wallabies, and hedgehogs. Not all introductions were successful; moose, Atlantic salmon, herring, lobster, partridge, and pheasants failed to establish a viable wild population. Others were extremely successful, to the point of becoming a pest. One of those species was deer.

Between 1851 and 1919, more than 250 red deer were imported from the UK and released in New Zealand for sport. They spread rapidly throughout both the North and South Island.

Wapiti, or North American elk, were introduced to New Zealand from their native North America in 1905, when 18 animals were released at the head of George Sound, Fiordland, and became quickly established. Ten of these animals were a gift from American President Theodore Roosevelt.

Several other species of deer were brought to New Zealand, but they didn’t do as well or spread as wide as the red deer or the wapiti.

Te Anau based Department of Conservation (DOC) Senior Ranger Biodiversity George Ledgard says that “because New Zealand native forests evolved without grazing mammals or any mammalian predators, deer quickly became wide-spread. Within a few decades their numbers were so high they became a real problem for our natural heritage.

“When deer populations get too large, their favourite plants – we call them the ‘ice cream species’ like broadleaf, three- and five-finger, hen and chicken fern, and lancewood – are all but removed from the ground tier in forest understories. Plants like alpine buttercup and tall tussocks are damaged by deer in subalpine habitats,” Ledgard adds and continues: “The result is a change in the structure and composition of the forest. You lose diversity which impacts on food availability and habitat for native birds and invertebrates.”

Possums (another import) and deer are a deadly combination for New Zealand’s native forests.

“Possums strip tree canopies of their young growth, while deer eat the seedlings sprouting from the ground and browse on the leaves of their favourite plants, stripping them as high up as they can reach. Stags can kill a tree by ringbarking it when they rub against its trunk. When an old tree dies and collapses, it creates a huge hole in the forest. If the understory is destroyed with the young seedlings eaten or trampled down, often the trees are replaced by canopy species non-palatable to deer, altering the structure and diversity of the forest,” Ledgard explains.

One of the worst-affected areas was Fiordland, home to such taonga (valued) species as takahē, kākāpō and kiwi. The red deer were spreading out of control. Large areas of Fiordland were experiencing severe damage to the native vegetation, including snow tussock – the main food of the takahē. By the end of the 19th century takahē were considered extinct largely due to loss of habitat caused by deer.

In order to halt the national crisis, in the 1930s the New Zealand government started issuing free hunting permits and paying deer cullers a bounty per deer-tail in an attempt to control numbers. Between 1932 and 1954, at least 1.4 million and possibly as many as 3 million deer were killed (Hunting, n.d.).

The New Zealand Deerstalkers Association was formed in Invercargill in 1938, partly as a response by recreational hunters to the government’s deer-culling efforts. Hunters were opposed to large-scale culling, which they felt would reduce their hunting opportunities. Deer are viewed by hunters as a valuable resource, but conservationists see them as pests that destroy native plants.

Stag in ferns
Photo: Luc Bombardier

In the 1960s, Germany began to purchase exported New Zealand venison; the deer market and hunting industry took off.

Initially, deer cullers hunted on foot and used horses and jet boats to transport deer back to game depots for sale. In 1965, Tim Wallis introduced the use of helicopters for carrying deer carcasses out of the bush. The technique of shooting deer from helicopters with doors removed became perfected by Rex Forrester, a recognised New Zealand hunting and fishing specialist.

In 1973, venison prices soared further, resulting in more operators entering the market and increasing illegal helicopter hunts. There were reports of shootings, arson, sabotage, and fist fights. In a documentary titled Deer Wars, director Paul Roy tells the story of how, over a 20 year period those early helicopter pioneers turned a national ecological disaster into a major export industry – but at a cost. Over 80 men died in the pursuit of deer and many more were seriously injured.

As a result of this hunting bonanza, the population of wild deer started to dwindle, and some hunters began talking about the possibility of farming deer. Tim Wallis pioneered live deer capture from helicopters, which led to the establishment of deer farms as a significant industry in New Zealand. With strong overseas demand for venison and the opening of deer velvet sales to Asia, deer farming became a very lucrative business. The need for breeding stock grew, and live-deer prices rose to $3,500 per beast.

Deer mob on deer farm, Te Anau
Photo: Nicola Essler

DOC regulates recreational hunting on conservation land, and issues permits. Almost all public conservation lands have open access with few restrictions on the number or species of deer killed. At popular hunting areas, such as Fiordland Wapiti Area, the Blue Mountains in West Otago (fallow deer), and Stewart Island (white-tailed deer), there are ballot systems restricting access and timing of hunting.

In parallel with attempts to keep deer numbers in check, DOC continued to search for methods of controlling other pests. One contentious issue has been the use of 1080 (sodium fluoroacetate) to reduce the spread of introduced predators, such as possums, rodents, and mustelids (ferrets, stoats, and weasels). Hunters are especially opposed to aerial drops of the poison, 1080, which is effective against predators, but also kills some deer and other wildlife.

According to Ledgard, deer numbers in Fiordland are nowadays controlled by the venison recovery programme, and helicopters are still the chief way of keeping their numbers down, particularly in the alpine areas where WARO (Wild Animal Recovery Operators) provide a huge benefit to FNP in reducing browse. WARO have been taking out about 5,000 deer from the park every year, for the last few decades.

“The number of deer harvested correlates to the price of venison. The recent drop in prices resulted in fewer animals being harvested and an increasing number of feral deer nationally,” he says.

The situation has become serious and the country is now looking to DOC for action on the deer issue. Early last year, Conservation Minister Eugenie Sage instructed her department to look at “the increasing deer abundance and spread, and the impacts on public conservation land.”

Dave Carlton, DOC Project Lead – Biodiversity Threats, has been charged with leading the development of a national strategy for deer management. The project was initiated following reports of damage by deer to forests in the Raukumara, Kaimai, and Mamaku Ranges with lessons learnt to be extended to the Ruahine, Kaweka, and Kaimanawa Ranges.

The Raukumara Forest Park, established in 1979, and covering 115,000ha of extremely rugged and remote, bush-clad land, made headlines back in 2019, when members of the local iwi – including Ngāti Porou, Te Whānau-ā-Apanui, Te Ehutu, Ngāi Tai, Whakatōhea and Te Aitanga-ā-Mahaki – raised alarm about the state of their forest and took their concerns to DOC. The symptoms were similar to other affected regions of Aotearoa: loss of birdsong, forest floor stripped bare, many dead trees (including giant tōtara) and an abundance of deer and possum droppings on the ground (Neilson, 2019).

“We started by assessing the size of the problem nationwide. People are talking about sightings of deer in numbers they haven’t seen for decades. Where the problem manifests itself is at the farm-forest fringe,” Carlton says.

According to Carlton, deer-farm escapees and illegal releases of deer cause loss of pasture on sheep and dairy farms. Herds of deer are also getting right to the city margins and becoming a problem in Auckland, Wellington, Christchurch, and even Oban on Stewart Island, where they get into people’s gardens and eat their vegetables.

A less-visible outcome of the deer population explosion is the damage to New Zealand native forests, resulting in loss of biodiversity, which can disturb the ecological equilibrium and, eventually, lead to a collapse of the forest and loss of native species.

“We are at the point where we are going to start developing a national framework for solving this problem, which we hope to have in place by the end of the year. We can’t develop a single strategy for the whole country, as the problem is different in different regions and the deer [species] are different, so we will end up with regional strategies,” Carlton says.

Deer provide livelihoods for many New Zealand farmers, particularly in Southland, and are an important source of food and recreation in Aotearoa. But the question remains whether we want to let our native forests be overrun by deer and watch the habitat of our taonga species destroyed, while the species themselves are driven to extinction.

 

 

Sources: 1. & 2. Acclimatisation society; Hunting, Te Ara, The Encyclopaedia of New Zealand 3. & 4. Acclimatisation Society; Helicopter-based hunting in Fiordland, Wikipedia 5. Deer, Department of Conservation 6. Our dying forest and the community mission to bring it back to life, NZ Herald 7. Deer Wars, NZONSCREEN

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