Tahr and chamois were introduced to New Zealand in the early days of European settlement for sport. Both animals have found the Southern Alps of the South Island ideal habitat, but have become a major threat to the ecosystems in these alpine areas.
Threat to native plants
Zora Creek, Landsborough, before thar impacts 2003 (left) and after tahr impacts 2012 Image: DOC
New Zealand’s native plants evolved over millions of years in isolation without any large mammal browsers. This makes them particularly vulnerable to damage from introduced mammals. Herding browsers such as tahr and chamois cause two-fold damage; firstly by eating native plants; secondly by trampling large areas of vegetation and compactable soils, when herds of animals gather together.
Tahr graze at high altitudes, in alpine grasslands and sub-alpine shrublands where they feed most intensively on tall snow tussock and can kill entire plants. Chamois eat a similar diet to tahr, but prefer more woody plants, particularly native brooms (Carmichaelia spp.), and herbs such as the Mount Cook lily (Ranunculus lyallii). Both animals are a major threat to the sensitive ecosystems of alpine regions, as their social nature increases pressure in localised areas.
Tahr and chamois are remarkably fast and agile in steep and rugged terrain. Their hooves are specially designed for surefootedness, with a combination of hard and soft surfaces to give excellent grip.
Tahr damage to the Mount Cook lily: Before (left) and after (right) Image: DOC
Himalayan tahr (Hemitragus jemlahicus) are large goat-like animals, native to the central Himalayan ranges of India and Nepal. In New Zealand tahr are found in the central Southern Alps between about the Rakaia and Whitcombe valleys in the north to about Lake Hawea in the south.
Tahr are generally found in the alpine grassland zone, where they graze on snow tussocks, alpine herbs and sub-alpine shrubland plants.
The male tahr’s summer coat is a reddish-brown, females a medium brown, both turning dark brown in winter. The bull tahr has an impressive mane of long hair around the neck and shoulders.
Tahr are popular with recreational and tourist hunters; their horns – and sometimes the male’s striking mane – are sought-after trophies.
Tahr are social animals and form easily recognisable groups. Adult females, yearlings and kids gather together, mature males over 4 years form bachelor groups, and younger males hang out together in separate, smaller groups. Males mix in with the females in their range over the winter breeding season but during the summer months they often travel long distances away from the female groups.
Eradication of tahr is not feasible - DOC's management policy for tahr is to control numbers in critical sites of high conservation value. Recreational and commercial hunters as well as DOC contribute to tahr control.
The Himalayan Tahr Control Plan 1993 is prepared under the Wild Animal Control Act 1977, and guides DOC’s control work, setting targets to keep the tahr population below 10,000 overall, and below specific densities in areas with high ecological value.
Monitoring is undertaken to follow trends in the tahr population and to understand the impacts of tahr on the alpine environment, both of which help inform management actions.
Reports on impacts of Himalayan tahr:
- Long-term impacts of an introduced ungulate in native grasslands: Himalayan tahr in New Zealand’s Southern Alps (PDF, 801K)
- Impact of Himalayan tahr on snow tussocks in the Southern Alps, New Zealand (2014) (PDF, 964K)
- Impact of Himalayan tahr on snow tussock grasslands in the Southern Alps (2004) (PDF, 12,131K)
Aerial surveys have been carried out over recent years to estimate the density and abundance of Himalayan tahr on public conservation land in each of the seven management units and two exclusion zones in the Southern Alps. The surveys were carried out on three occasions at 66, 2 x 2 km plots located on public conservation land during 2016, 2017 and 2018.
For a full report on the aerial surveys see: Estimates of Himalayan tahr abundance in New Zealand: Results from aerial surveys (PDF, 1220K)
Key results were:
- the total abundance of tahr on public conservation land for the period 2016 – 2018 was estimated to be 34,292 individuals (95% confidence interval; 24,777 – 47,461)
- tahr abundances were highest in management units 3 and 4 (approximately 8,000 tahr in each), and were lowest in management unit 7 and the two exclusion zones (approximately 100 -150 tahr in each)
- average tahr density over the three years of sampling was highest in management unit 3 (9.2 tahr/km2) and lowest in exclusion zone 2 (0.06 tahr/km2).
DOC undertook further tahr population monitoring in early 2019 which will further improve our estimates of the tahr population across the management zones and assist with the planning of future tahr control.
You can help
If you see large groups of tahr in areas outside their feral range, let the local DOC office know.
Take part in a hunt – you will have a great outdoor adventure as well as contributing to keeping tahr or chamois numbers down. Just make sure you have your hunting permits and licences. Always identify your target.