A British duke sent six Himalayan tahr to New Zealand in 1904; five survived the voyage, and their descendants later grew into tens of thousands that now damage fragile alpine ecosystems

The Himalayan tahr is a large, shaggy mountain ungulate native to the Himalayas that has become an invasive species in New Zealand.

In 1904, a gift from a British aristocrat brought a handful of shaggy mountain goats to the remote peaks of New Zealand’s South Island. The aim was to build up big game stocks for visiting sport hunters. But those few animals started an environmental problem that still worries conservationists and land managers today. The animal at the centre of the issue is the Himalayan tahr (Hemitragus jemlahicus), a strong mountain animal native to the highlands of Asia. In its native range, the species is listed as near threatened by the International Union for Conservation of Nature (IUCN). But across New Zealand’s Southern Alps, thousands of miles away, the tahr has multiplied so successfully that it is now treated as an invasive pest.

A royal gift takes root

The story began when the 11th Duke of Bedford sent six tahr from his Woburn Abbey estate in Bedfordshire, England, to the New Zealand government. The shipment was meant to create new hunting opportunities for English settlers and visiting tourists. During the difficult sea journey, one animal jumped overboard, leaving five survivors, three males and two females, to be released near the Hermitage at Mount Cook. Seeing the potential for the animals to multiply, the Duke sent another group from his herd in 1909. According to historical records documented by Heli Rural, five more animals survived that journey. The founding herd was given legal protection by local authorities and quickly adapted to the high altitude landscape. Within ten years, the population was estimated at about 100 animals. By the middle of the 20th century, their numbers had grown dramatically. The steep, rocky mountains of the Southern Alps were similar to the harsh alpine environments of the Himalayas. But unlike their native range, New Zealand had no natural predators such as the snow leopard to control their numbers. The tahr spread across the main mountain ranges from Arthur’s Pass to Haast Pass.

Threat to high country plants

By the 1950s, the environmental damage caused by the growing herds had become clear. Tahr are heavy grazers. Their specialised hooves have a soft, rubbery centre that helps them grip smooth rock, along with hard outer edges that help them move across steep cliffs. They feed on alpine grasses, tussocks and native shrubs. New Zealand’s native plants had evolved without large land mammals. As a result, many fragile alpine species had little protection against heavy grazing. Plants such as the Mount Cook lily (Ranunculus lyallii) and tall snow tussocks suffered serious damage. Heavy grazing removed vegetation from delicate soils and increased erosion. The government removed the tahr’s protected status in 1930, allowing unrestricted hunting. By 1937, official culling programmes were underway. Government hunters killed thousands of animals over the following decades, but the difficult mountain terrain made complete removal almost impossible. A major change came in the late 1960s, when helicopters were introduced for aerial shooting. Culling teams could now reach remote cliffs and high ridges where tahr had previously found shelter. According to historical accounts on Heli Rural, intensive aerial control reduced the population by an estimated 90 percent by the early 1980s, leaving about 2,000 animals in the wild.

The modern conservation dilemma

When culling was reduced, tahr numbers quickly began to rise again. In response, the newly created Department of Conservation (DOC), established in 1987, introduced the Himalayan Thar Control Plan in 1993. The policy set a target of keeping the wild population below 10,000 animals across a designated feral range covering about 17,000 square kilometres of public land. The plan combined targeted DOC culling with commercial and recreational hunting to control the population. Despite these efforts, later aerial surveys showed that tahr numbers had again risen well above the official limit, reaching tens of thousands. This led to renewed controversy when the Department of Conservation announced larger culling operations to protect fragile national park ecosystems. The move faced opposition from hunting groups, commercial guides and game outfitters. Over the decades, tahr hunting had developed into a multi-million-dollar safari industry, attracting international hunters who wanted to hunt trophy bulls with thick, swept-back horns and long, straw-coloured winter manes. Today, authorities face a difficult balance. Conservationists warn that uncontrolled herds can strip high-altitude wilderness of native plants and disturb fragile ecosystems. At the same time, local communities and hunting groups see the tahr as an important recreational and economic resource. More than a century after five mountain animals stepped off a ship from England, their descendants remain one of the most visible and controversial introduced species in New Zealand and one of the Southern Hemisphere’s most difficult wildlife management challenges.