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Dung, Giao, Chinh, Tuoc, Arctander, MacKinnon, 1993
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Dung, Giao, Chinh, Tuoc, Arctander, MacKinnon, 1993
The saola, Vu Quang ox or Asian unicorn, also, infrequently, Vu Quang bovid (Pseudoryx nghetinhensis), is one of the world's rarest mammals, a forest-dwelling bovine found only in the Annamite Range of Vietnam and Laos. Cousin to cattle, goats, and antelopes, the species was defined following a discovery of remains in 1992 in Vũ Quang Nature Reserve by a joint survey of the Ministry of Forestry and the World Wide Fund for Nature. The team found three skulls with unusual, long, straight horns kept in hunters' houses. In their article, the team proposed "a three month survey to observe the living animal", but more than 20 years later, still no sighting of a saola in the wild had been reported by a scientist. However, a living saola was photographed in the wild in September 2013 by a camera trap set by the World Wide Fund for Nature and the Vietnamese government’s Forest Protection Department. Van Ngoc Thinh, the WWF's Vietnam country director, said, "This is a breathtaking discovery and renews hope for the recovery of the species."
In late August 2010, a saola was captured by villagers in Laos, but died in captivity before government conservationists could arrange for it to be released back into the wild. The carcass is being studied with the hope that it will advance scientific understanding of the saola. Sometimes, these animals get caught in snares that have been set to catch animals such as wild boar, sambar, and muntjac deer that come to feed on the crops the farmers have planted. This has become a problem, especially with the illegal fur trade, for medicines, restaurants, and food markets. More than 26,651 snares have been removed from habitats where the saola has lived for years.
The saola inhabits the Annamite Range's moist forests and the eastern Indochina dry and monsoon forests. They have been spotted in steep river valleys at about 300 to 1800 m above sea level. These regions are distant from human settlements, and covered primarily in evergreen or mixed evergreen and deciduous woodlands. The species seems to prefer edge zones of the forests.
Saolas stay in mountain forests during the wet seasons, when water in streams and rivers is abundant, and move down to the lowlands in winter. They are shy and never enter cultivated fields or come close to villages. To date, all known captive saolas have died, leading to the belief that this species cannot live in captivity.
The saola belongs to the family Bovidae, and genetic analysis places it in the tribe Bovini; its closest relatives are cattle, true buffaloes, and bison. However, its simple horns and teeth and some other morphological features are typical of less-derived or 'primitive' bovids. Saolas are antelopes, in the sense that an antelope is any bovid that is not a cow, sheep, buffalo, bison, or goat. How many individuals exist is unknown, as only 11 have been recorded alive.
An adult saola stands at about 80–90 cm at the shoulder, with its entire body length measuring around 150 cm (the tail measures additionally out to about 25 cm) and weighs 90–100 kg. Its hair is straight, short, and surprisingly soft for an animal partly adapted to a montane habitat, and is usually of a medium chocolate brown color (though some have been noted to contain variations of a reddish tone). However, this is not uniform, with both the neck and belly a slightly paler shade, as well as various white markings scattered across its body, such as white patches on the feet, vertical stripes across the cheeks, and splotches on the nose and chin. Also, a medial black dorsal strip extends from between the shoulders down and back to fade out into the top of the tail. The tail itself is tricolored and splits evenly into three horizontal bands of medium brown, cream, and black, with the cream blending into the white band that extends across its rear. It bears round pupils with dark-brown irises and a cluster of white whiskers about 2 cm long that protrude from the end of the chin with a presumably tactile function. It also possesses a long tongue that can extend up to about 16 cm, with its upper surface covered in fine, rearward-pointing barbs, presumably to aid in eating.
All saolas also possess a pair of slightly diverging horns that closely resemble the parallel wooden posts commonly used to support a spinning wheel (which is also the source of their namesake). They are generally dark-brown or black and can measure from about 35–50 cm long; twice the length of their head. The horns of the males and females bear little to no significant variations. Their skin is 1–2 mm thick over most of the body, but thickens near the nape of the neck, and at the upper shoulders, it thickens to 5 mm. This unique adaptation protects them against both predators and rivals' horns during fights.
Local populations report having seen saolas traveling in groups of two or three, rarely more.
The saola possesses a pair of highly developed maxillary glands on either side of its snout, each comprising a rectangular shallow depression of about 1.5 cm deep along the upper muzzle. The depression is covered by sparse, flattened hair with rows of pores scattered throughout. The entirety of each gland is covered by a muscular flap that can raise up to about 3 cm to expose scent glands used in marking territory. It then subsequently can rub the underside against objects, leaving a musky, pungent paste. The saola's colossal scent glands are thought to be the largest of any living mammal.
They walk with a gentle, quiet, slow nature. When they sleep, they have their fore legs tucked under their bodies, necks extended, and the chin resting on the floor. Villagers reported that saolas are active in the mornings, afternoons, and nights, but not when the sun is overhead.
They are calm in the presence of humans, letting humans pet them and eat out of their hands. However, they have an intense fear of dogs. When they feel threatened, they contract defensive positions which involve the snorting and thrusting of their heads forward, exposing their long, straight horns. Their ears are pointed up and straight back with arched backs and stiff postures. Occasionally, they secrete the paste from their maxillary glands as a defensive reaction, which is usually and most commonly observed with dogs. Saola vocalize with bleats.
To mark their territories, saolas open a fleshy flap located over their maxillary glands on either side of the snout and rub it over a rock or place of territory, leaving a strong, musky paste. To defecate and urinate, saolas drop their hind legs and lower the lower body, urinating and defecating separately, which is not new for bovid species.
Saolas spend a significant amount of time grooming themselves. They lick their faces and eyes most often and lead into their shoulders and fore legs. They frequently lick their muzzles to disperse flies, as well.
Very little information is available about their reproductive and pregnancy cycles; however, they give birth to single calves. A female saola held captive died pregnant with a male calf, which was well formed and had distinguishable features. For lack of information and proper resources, scientists estimate the gestation period as similar to those of Tragelaphus species; that is, about 234 days.
They are reported to eat small leafy plants, especially fig leaves and stems, along rivers. While little is known about the full range of their diet, saolas in captivity generally subsist on a diet of leafy plants such as a Asplenium fern species (also known as spleenwort), broad dark-green plants of the Homalomena genus, and various species of broad-leaved shrubs or trees of the Sterculiaceae family. They have shown to have a greater preference for the unidentified plant of the Sterculiaceae family/Sterculia genus. Seldom have they been reported eating during periods of darkness, most likely due to their diurnal nature. The animal seems to have a browsing diet, considering its small incisors.
The name saola has been translated as "spindle[-horned]" although the precise meaning is actually "spinning-wheel post horn". The name comes from a Tai language of Vietnam, but the meaning is the same in the Lao language. The specific name nghetinhensis refers to the two Vietnamese provinces of Nghệ An and Hà Tĩnh while Pseudoryx acknowledges the animal's similarities with the Arabian or African oryx. Hmong people in Laos refer to this beast as saht-supahp, a term derived from Lao meaning "the polite animal", because it moves quietly through the forest. Other names used by minority groups in the Saola's range are lagiang (Van Kieu), a ngao (Ta Oi) and xoong xor (Katu)  In the press, saolas have been referred to as "Asian unicorns". The appellation is apparently due to the saola's rarity and apparently gentle nature and perhaps because both the saola and the oryx have been linked with the unicorn. No known link with the mythical beast is known; nor with the "Chinese unicorn", the qilin.
Aside from a long gestation period, the saola has been an easy target for hunters due to its docile nature. Additionally, it is occasionally caught by snares set by villagers for wild boar. Feral and domestic dogs present another threat, as the ecology of the area historically has not included a canine predator. In several instances, the villagers hang the horns of the saola as a symbol of honor. Such trophy hunting endangers the species as a whole because they have very little defense and can be overpowered quite easily. Little money is available to fund the awareness of the endangered status of this species, let alone for its conservation, so trophy hunting continues with no regulation.
Another large threat to the saola species is habitat fragmentation. Due to their shy nature and preference for undisturbed forests, the habitable region for the saola continues to shrink. They are restricted to high mountain areas where perhaps a few dozen to a few hundred animals remain.
In 1992, the saola was discovered within the restricted mountainous region that separates Vietnam and Laos. Only a few hundred of them are reported in the wild. The horn cores of the adult saola are exceptionally long, and the genetic name Pseudoryx refers to the superficial resemblance of the oryx (tribe Hippotragini). As compared to other bovid genera, Pseudoryx differs significantly from all described in appearance and morphology. The Bovidae are composed of two major subfamilial clades, based on molecular investigations of ribosomal mitochondrial sequences of a large taxon sample. The first clade corresponds to Bovidae and assembles members of the tribes Bovini (cattle and buffaloes), Tragelaphini (African spiral-horned bovids) and Bosalaphini. The second clusters all other bovids, which is composed of Caprini (goats and muskox), Hippotragini (horse-like antelopes), and Antilopini (gazelles). Phylogenetic information for deciphering Bovidae evolution can be found in mitochondrial and nuclear sequences.
The Saola Working Group was formed by the IUCN Species Survival Commission's Asian Wild Cattle Specialist Group, in 2006 to protect the saolas and their habitat. This coalition includes about 40 experts from the forestry departments of Laos and Vietnam, Vietnam's Institute of Ecology and Biological Resources, Vinh University, biologists and conservationists from Wildlife Conservation Society, and the World Wide Fund for Nature.
Due to the saola being critically endangered, a group of scientists from the Vietnam Academy of Science and Technology in central Hanoi, within the Institute of Biotechnology, has looked into a last resort effort of conserving the species by cloning. This can prove to be quite difficult because cloning even the most well-known mammal can be difficult. It would be even more so with a mammal about which researchers know little to nothing, such as the saola.
Other rarely seen large mammals of the Indochina peninsula, also discovered in the 1990s:
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