Hemitragus jayakari

Geographic Range

Arabian tahrs are currently found in the Hajar Mountains of the United Arab Emirates and the northern parts of Oman. The current known range is 8,863 square kilometers, and the total possible range is 15,787 square kilometers.

• Biogeographic Regions
• palearctic palearctic
  • native native

Habitat

Arabian tahrs have a limited range geographically and are possibly extinct in the United Arab Emirates. They inhabit north slopes of the Hajar Mountains and Musandan masifs, where they persist on steep ground. Tahrs occupy the relatively rainy slopes of these mountains which contain enough water and diverse vegetation for them to survive. At the bottoms of these mountains, water sources in valleys, called wadis, are important for the survival of Arabian tahrs.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• scrub forest scrub forest
• mountains mountains

Physical Description

Hemitragus jayakari the smallest tahr species. Both sexes possess horns pointing backwards, although the horns of males are larger and more dense than those of females. The hair is long and reddish with a dark brown stripe running down the back from the head to the tail. Males grow noticeable manes every year along their backs and have impressive, long hair on their chins and chests and extending to their front legs, that can grow quite long. Their hooves are supple and provide traction in their mountainous terrain. Males weigh approximately 40 kg and females weigh 17 to 20 kg. They are 59.7 to 63.5 cm height at the shoulder, compared to Himalayan tahrs and Nilgiri tahrs (both around 101.6 cm).

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• male more colorful
• ornamentation ornamentation

Reproduction

Arabian tahrs seem to be monogamous, with most observations being of a single male with a single female in the male's territory. They are unusual among bovids in defending territories. Males use their urine to mark their territory and their mates. Their horns are used in male-male combat over females.

It is interesting that Himalayan tahr and Nilgiri tahr are polygamous and Hemitragus jayakari is only polygamous in captivity. Perhaps the decline of resources, habitat destruction, and their resultant rarity prevents Arabian tahrs from being polygamous or forming large groups in the wild.

• Mating System
• monogamous monogamous

Breeding in Arabian tahrs occurs year-round and is opportunistic. They find a mate and form small exclusive groups of two to four related individuals. They do not form rutting herds. Copulation occurs year round, but optimum breeding is in the months of November and December. When resources are abundant, it is common for females to give birth to up to two offspring. Gestation is for 140 to 145 days, leading to peak birthing in March and April. Young Arabian tahrs may not breed until they are 2 to 3 years old.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Arabian tahr females gestate, nurse, and protect their young until independence. Males may contribute through defending territories with good resources and helping to defend the young, although there are few observations in the wild. Arabian tahr young remain with their mother or with the male and female parents for 2 to 3 years before becoming independent.

• Parental Investment
• precocial precocial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • male
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • male
    • female
• post-independence association with parents

Lifespan/Longevity

Arabian tahrs have a lifespan in captivity of up to 22 years. With predation, hunting, and destruction of habitat, the lifespan in the wild is lower. There is insufficient research to determine lifespan in the wild. The main factor limiting lifespan is the amount of resources present, which is currently linked to competition with domestic animals.

Behavior

Arabian tahrs are diurnal and begin grazing in the early morning for most of the day until a few hours before dusk. They travel along steep mountain grades to reach good foraging areas and available water, sometimes descending to lowlands to reach "wadis," water sources. They can be solitary but are typically found in small groups of two or three, the combination usually being a female and her young, a female and male, or a female, male, and their young. However, when they are bred in captivity, they form larger groups with more complex social hierarchies. This suggests the possibility that social structures in the wild have changed as a result of their extreme rarity and isolation to potentially marginal habitat.

• Key Behaviors
• terricolous
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial
• social social

Home Range

Arabian tahr males mark their territory by scratching their hooves on the ground and urinating. The average area covered by an Arabian tahr is 0.3 square kilometers, which usually contains water and vegetation. When this water supply is not enough, they temporarily travel outside of their territory.

Communication and Perception

Visual, auditory, and chemical communications are used by Arabian tahrs. Males use urine to mark territory as well as their mates.

• Communication Channels
• visual visual
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Arabian tahrs are strict browsers, eating mainly leaves, bark, seeds, and fruits in the diverse vegetation they prefer. Water is usually the limiting resource and droughts can seriously affect Arabian tahr populations.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves
• wood, bark, or stems
• seeds, grains, and nuts
• fruit

Predation

Their rubbery hooves allow quick and sure movements around cliffs and rocks. The horns are pointed backwards but are robust and could be used defensively. Long, shaggy, reddish-brown pelage helps to camouflage them in their scrubby habitat. They were once preyed on by Arabian leopards ( Panthera pardus nimr ) and humans ( Homo sapiens ).

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Arabian tahrs are an indicator of the condition of their habitat. They are currently only found in remote, mountainous areas with relatively higher precipitation. Their presence is important for Arabian leopards, which prey on them. Arabian leopards number fewer than 250 individuals in the wild. Arabian tahrs also impact vegetation communities through their browsing.

Economic Importance for Humans: Positive

Arabian tahrs were once hunted for sport and meat. Some poaching may continue, but is illegal, as Arabian tahrs are highly endangered and protected by law. Some Arabian tahrs are bred in captivity and much is learned about their life histories in that context, since observations in the wild are difficult to obtain.

• Positive Impacts
• food food
• research and education

Economic Importance for Humans: Negative

There are no known adverse effects of Hemitragus jayakari on humans.

Conservation Status

The number of Arabian tahrs is currently estimated to be fewer than 2,500 individuals. Subpopulations are fragmentary and small, with none having more than 250 individuals. Populations continue to decline despite protective measures and captive breeding. The largest cause of decline in Arabian tahrs is loss of habitat. Poaching and competition with domestic goats for resources also contribute to the decline. Poaching still threatens tahrs, as does diseases spread by domestic animals. In the future, increased mining threatens habitat quality and water availability.

In Oman, it is illegal to hunt Arabian tahrs. Measures taken to enforce this include appointing tribesmen to be tahr guards, thus protecting their habitat. Also, local farming families have been notified to keep their livestock away from contact with the tahrs. Currently, tahrs living in captivity are not considered ready for release and reintroductions have not been attempted. Future measures to save wild Arabian tahrs include better systems for raising them in captivity as well as establishing official reserves. Stronger enforcement of current rules is necessary as well.

Other Comments

Debate is currently being held over whether or not the three existing species of tahrs deserve a monospecific genera. Hemitragus is currently used for all three, but it is suggested that this name should only apply to Himalayan tahrs ( Hemitragus jemlahicus ). The suggested generic name for Arabian tahr would be Arabitragus , and Nilgiritragus would be used for Nilgiri tahr ( Hemitragus hylocrius ). The alternative name for Hemitragus jakari would then be Arabitragus jakari .

Additional Links

Encyclopedia of Life

Contributors

Alexander Emmitt (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Tanya Dewey (editor), Animal Diversity Web.

References

Burton, M., R. Burton. 2002. International Wildlife Encyclopedia . New York City: Marshall Cavendish.

Burton, M., R. Burton. 2002. Tahr. Pp. 2612-2613 in International Wildlife Encyclopedia , Vol. 17, 3 Edition. New York, NY: Marshall Cavendish.

Insall, D. 2008. "IUCN 2008 Red List" (On-line). Arabitragus jayakari. Accessed May 08, 2009 at http://www.iucnredlist.org/details/9918 .

Robinson, M. 2005. The Arabian Tahr: A Review of its Biology and Conservation. Newsletter of the IUCN/SSC Caprinae Specialist Group , October: 2-8. Accessed May 08, 2009 at http://pages.usherbrooke.ca/mfesta/pdffiles/Oct%2005.pdf .

Ropiquet, A., A. Hassanin. 2005. Molecular evidence for the polyphyly of the genus Hemitragus (Mammalia, Bovidae). Molecular Phylogenetics and Evolution , Vol. 36, Iss. 1: 154-168. Accessed May 08, 2009 at http://www.sciencedirect.com.proxy.lib.umich.edu/science?_ob=ArticleURL&_udi=B6WNH-4FG2X4F-1&_user=99318&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000007678&_version=1&_urlVersion=0&_userid=99318&md5=a59aaed2f851711a2043f5518da8f80d .

Wildscreen. 2009. "ARKive: Images of Life on Earth" (On-line). Arabian Leopard. Accessed May 08, 2009 at http://www.arkive.org/arabian-leopard/panthera-pardus-nimr/biology.html .

Wildscreen. 2009. "ARKive: Images of Life on Earth" (On-line). Arabian Tahr. Accessed May 08, 2009 at http://www.arkive.org/arabian-tahr/hemitragus-jayakari/info.html .