Himalayan 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.
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.
Tahr 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.
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, juveniles 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.
Threat to native plants
Zora Canyon, Landsborough in 1999 (left) and 2020 (right) showing the impact of tahr
New Zealand alpine ecosystems evolved over millions of years in isolation without any large mammal browsers (such as tahr), and many alpine plants have no defence mechanisms (such as toxins or spines) to discourage tahr from eating them.
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 and browse on native plants that birds, lizards and insects use for feeding, nesting and shelter. The tahr diet includes some large, succulent herbaceous species including alpine buttercups and mountain daisies. Some of these species are ranked as Threatened or At Risk by the New Zealand Threat Classification System.
Tahr also feed on snow tussock and shrub species which are the dominant vegetation in many of New Zealand’s subalpine and alpine environments. Tahr are a major threat to the sensitive ecosystems of alpine regions, as their social nature increases pressure in localised areas. In extreme situations, large groups of tahr can transform tall tussocks and subalpine shrublands to a grassy turf or bare ground.
DOC has been recording the impacts of Himalayan tahr on alpine and subalpine biodiversity since the early 1990s by monitoring a network of 117 permanent plots in alpine grasslands within the tahr management units. New research since 2011 has established that there is less shrub cover in the tahr management areas than in the tahr exclusion zones (the areas to the north and south of the tahr feral range).
There are very few tahr in the exclusion zones, as all tahr present in these areas are targeted for removal to prevent the tahr feral range from expanding. High tahr numbers have led to a drastic change in the vegetation at Zora Canyon, South Westland, with tall snow tussocks in some places almost gone.
Tahr damage to the Mount Cook lily – before (left) and after (right)
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.
Legislation allows for a managed population of up to 10,000 tahr across Crown pastoral leases, private land and public conservation land to co-exist with our native species.
DOC is aiming for population control, not eradication. There’s no intention or risk of tahr being eradicated now or in the future, but we do need to meet the objectives of the Himalayan Thar Control Plan 1993.
The Himalayan Thar 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. DOC is using non-lead ammunition for tahr control operations in kea habitat.
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)
- Potential of Tier 1 and alternative monitoring networks to assess the ecological integrity of alpine vegetation exposed to tahr grazing (PDF, 3,999K)
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.
After three summer seasons of tahr population monitoring, the total abundance of tahr on public conservation land between 2016 and 2019 was estimated to be 34,478 animals (95% confidence interval: 26,522–44,821). This estimate does not include tahr herds on other land tenures.
The current estimate is an average abundance over the three seasons of data collection using aerial surveys in the tahr management areas on public conservation land. This means we effectively average over any additions (tahr births) or losses (tahr deaths due to control operations and natural causes) to the population during this period.
The population assessment was made prior to control by DOC, commercial hunters and contractors who collectively removed approximately 11,000 tahr during July to November 2019. There has since been another breeding season and further control in recent months.
The assessment from Autumn 2019 is included below along with a factsheet and a previous report.
Population monitoring reports:
- Factsheet: Estimating Himalayan tahr numbers in New Zealand (PDF, 886K)
- Estimates of Himalayan tahr abundance in New Zealand September 2019 (PDF, 1,741K)
- Estimates of Himalayan tahr abundance in New Zealand 2015-2018 (PDF, 1220K)
You can help
If you see 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 permit.
Tahr Returns app
Use the app to record the number of Himalayan tahr you've hunted.
Find tahr hunting ‘hotspots’
DOC is mapping the locations of tahr observed on public conservation land.