Himalayan tahr

The Himalayan tahr (Hemitragus jemlahicus) is a large even-toed ungulate native to the Himalayas in southern Tibet, northern India, western Bhutan and Nepal. It is listed as Near Threatened on the IUCN Red List, as the population is declining due to hunting and habitat loss.

Taxonomy and phylogeny

Tahr belong to the subfamily Caprinae in the order Artiodactyla. Their closest relatives in the subfamily Caprinae are sheep and goats.

A subspecies, the Eastern Himalayan tahr or shapi, was described in 1944. This classification is not considered valid anymore, and no subspecies are currently recognized.

Etymology

The word "tahr," first used in English writings in 1835, is derived from the animal's local name in the Western Himalayas, which has otherwise been rendered as "tehr," "tare" and "tahir". Through confusion with thār, a Nepali word for the Himalayan serow, it has also been spelled "thar."

The genus name Hemitragus is derived from the Greek words hēmi- meaning "half" and trágos meaning "goat".

Characteristics

The Himalayan tahr has a small head, small pointed ears, large eyes, and horns that vary between males and females. The exterior of a tahr is well adapted to the harsh climate of the Himalayans. They sport thick, reddish wool coats and thick undercoats, indicative of the conditions of their habitat. Their coats thin with the end of winter and becomes lighter in color.

As a member of the ungulate group of mammals, the Himalayan tahr possesses an even number of toes. They have adapted the unique ability to grasp both smooth and rough surfaces that are typical of the mountainous terrain on which they reside. This useful characteristic also helps their mobility. The hooves of the tahr have a rubber-like core which allows for gripping smooth rocks while keratin at the rim of their hooves allow increased hoof durability, which is important for traversing the rocky ground. This adaptation allows for confident and swift maneuvering of the terrain.

Behaviour and ecology

thumb|Male, female and young, drinking from the [[Bhagirathi River in Uttarkashi, Uttarakhand, India.]]

thumb|Three individuals on a snowy ridge in the Annapurna region of Nepal.

The Himalayan tahr is adapted to life in a cool climate with rocky terrain, which allows them to be found in mountainous areas. In the Himalayas, they are mainly found on slopes ranging from 2,500 to 5,000 m. Himalayan tahr can eat a wide variety of plants. They most often inhabit locations where vegetation is exposed for browsing and grazing. During the winter (when snow covers vegetation at higher elevations), they are found on lower-altitude slopes.

Diet

The Himalayan tahr is a herbivore spending most of the time grazing on grasses and browsing on leaves and some fruits. with as much as 75% of its diet consisting of natural grasses.

Predation

Tahr are preyed upon by snow leopards. Factors that contribute to which males dominate include size, weight, and testosterone levels. Coat color can have an effect; Himalayan tahrs with lighter coats are more likely to gain access to estrous females

Himalayan tahrs have precocious young which can stand soon after birth. Competition can occur when two or more species share a limited resource, such as particular food sources, in a given area. Since the Himalayan tahr and the other ungulates are eating the same foods, competition possibly is occurring among them.

Introduction as an invasive species

thumb|Young tahr

thumb|A female Himalayan tahr at [[Prague Zoo]]

A key factor contributing to the success of the Himalayan tahr as an invasive species is their mobility. During the night, they move to locations with lower elevations to have better access to resources such as food and water, whereas during the day, they move to locations with higher elevation to rest and avoid predators.

Lastly, the Himalayan tahr lacks predators in the regions where it has been introduced, so is only limited by access to food and water, and its own reproductive rate. The IUCN lists the tahr as being possibly extirpated from Argentina despite its introduction.

New Zealand

Himalayan tahr were introduced to New Zealand in 1904 around the Mount Cook region for sport and have since expanded rapidly into neighboring areas. Their heavy grazing of native plants in New Zealand has caused significant environmental damage. They currently inhabit a portion of the Southern Alps and are still being hunted for sport. The Department of Conservation (DOC) culled 12,000 tahr between July 2019 and February 2020, and over 7,000 between July and November 2020.

Groups such as hunters and farmers have resisted tahr eradication. A report prepared in 2005 by Kenneth F.D. Hughey and Karen M. Wason presented the results of a survey conducted among 43 farmers living within tahr distribution. Roughly 80% of farmers view tahr as a resource, not as a threat. The respondents indicated they placed conservational and commercial value (live animal/meat, hunting, farming) on tahr. Thirty six percent of these farmers also reported to having earned at least $1,000 a year in profit from having tahr on their property, with the highest earnings being above $50,000 (Table 5.5 of that study), usually as a result of allowing professionally guided hunters on their property.

Tahr could be eradicated from New Zealand but "this has not happened due to intense lobbying pressure from hunting interests, so ongoing ecological costs are incurred by the natural environment."

The hunting lobby has protested against the culling of tahr in 2020. DOC released a management plan for 2020–2021 which was contested in the High Court. The Court ruled that DOC should consult with interested parties and stakeholders which resulted in a number of changes to the plan; the revised plan was welcomed by the Tahr Foundation.

Impact as an invasive species

A negative impact the Himalayan tahrs have on their environment is increased herbivory on the native vegetation of the ecosystem, which can make it harder for other herbivores to find food. The increased herbivory can also lead to a decrease in soil nutrients, such as oxygen, nitrates, and ammonia, resulting in positive feedback loop, making it harder for plants to grow at all. Consequently, the natural fauna of the ecosystem is heavily affected. This increase has also resulted in poor soil quality in many environments occupied by the Himalayan tahr and has severely limited the presence of certain plant species. The lack of certain vegetation, in turn, may affect animal species that rely on them as a food source.

Data on the rapid expansion of the tahr are documented by government agencies. Over a time span of 16 years, the Himalayan tahr reached up to 33 tahr/km2 in New Zealand – twice the initial population (2*N0). Without regulated hunting or the presence of natural barriers, the Himalayan tahr can pose a large threat to the indigenous fauna and flora populations within the area. although the species is still considered to be endangered in the Himalayas on the IUCN Red List. Under the plan, the area of the tahr distribution was divided into two exclusion zones and seven management units. The exclusion zones set boundaries on the area that the tahr inhabits, with the official control operations to be employed to prevent them from spreading beyond those zones. The management unit has a fixed maximum density, which varies from 1–2.5 tahr/km2 and is considered to be low enough to have a minimal negative impact on the ecosystem and, even, restore native vegetation. Under these conditions, the plan aimed to keep tahr numbers below 10,000 throughout the South Island. Water samples after baiting operations did not reveal dangerous levels of the compound. In the soil, sodium monofluoroacetate is converted by bacteria and fungi to metabolic products, shown to be nonhazardous to the environment.

According to Australia's Department of Primary Industries, Parks, Water, and Environment,

South Africa

The Himalayan tahr was introduced to South Africa when in the 1930s, two Himalayan tahrs escaped from a zoo in Cape Town. Subsequent populations of tahrs have descended from the original escaped pair and spread quickly over the Cape Peninsular mountain range. Most of the population has been culled to make way for the reintroduction of the indigenous antelope, the klipspringer.

United States

The Himalayan tahr is present in New Mexico, where it has been introduced. According to the New Mexico Department of Game and Fish news release dated 28 May 2014, "Only one Wildlife Management Area, Water Canyon, allows hunting for nongame species as a management tool for the non-native Himalayan tahr, a large ungulate related to the wild goat." However, outside of Water Canyon Wildlife Management Area, Himalayan tahr may be taken. There is no closed season or bag limit on Himalayan tahr, and they may be hunted even with an airgun.

Notes

References

External links

ARKive – Images and movies of the Himalayan tahr (Hemitragus jemlahicus)
Fact sheet on the Himalayan tahr