Saola

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Saola
Pseudoryx nghetinhensis, b.PNG
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Pseudoryx
Species: P. nghetinhensis
Binomial name
Pseudoryx nghetinhensis
Dung, Giao, Chinh, Tuoc, Arctander, MacKinnon, 1993
Pseudoryx nghetinhensis distribution.png

The Saola, Vu Quang ox or Asian biocorn, 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. Related to cattle, goats, and antelopes,[2][3] 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.[4] Saolas have since been kept in captivity multiple times, although only for short periods. A living saola in the wild was first photographed in 1999 by a camera trap set by WWF and the Vietnamese government’s Forest Protection Department (SFNC).[5][6]

Description[edit]

Some of the first known remains of this species, Zoological Museum of Copenhagen

An adult saola stands at about 80–90 cm at the shoulder, with its entire body length measuring around 150 cm (the tail measures an additional 25 cm) and weighs 90–100 kg (approx. 200-220 lbs.). Its hair is straight, short, and unusually 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). Neck and belly are of 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. A black dorsal strip extends from between the shoulders down and back to fade out into the top of the tail. The tail is tricolored, splitting evenly into three horizontal bands of medium brown, cream, and black, with the cream blending into the white band that extends across its rear.[7]

Saolas of both sexes possess a pair of slightly diverging horns that resemble the parallel wooden posts locally used to support a spinning wheel (thus the familiar name "spindlehorn").[3] These are generally dark-brown or black and about 35–50 cm long; twice the length of their head.[7] There appear to be no significant differences between the horns of males and females. The saola has round pupils with dark-brown irises and a cluster of white whiskers about 2 cm long with a presumably tactile function that protrude from the end of the chin. Its tongue can extend up to about 16 cm, with its upper surface covered in fine, backward-pointing barbs.[7] Saola skin is 1–2 mm thick over most of the body, but thickens to 5 mm near the nape of the neck and at the upper shoulders. This adaptation is thought to protect against both predators and rivals' horns during fights.[8]

The saola possesses a pair of highly developed maxillary glands on either side of its snout, used in marking territory. Glands consist of rectangular shallow depressions of about 1.5 cm deep along the upper muzzle, covered by a muscular flap that can be raised about 3 cm to expose the gland. Scent glands are rubbed against the underside of vegetation, leaving a musky, pungent paste.[7] The saola's scent glands are thought to be the largest of any living mammal.[citation needed]

Taxonomy and evolution[edit]

In 1992, the founding of saola lifted a huge scientific interest due to the special physical traits of saola. Also, because of its unique physical traits, saola becomes a new genus group (Pseudoryx). But, since its physical traits are so complex to classify, it had been classify as Pseudoryx and Caprinae whereas it is now been classify in three tribes: Boselaphini, Bovini and Tragelaphini. According to recent DNA analysis, scientists conclude saola should be classified as tribe Bovini. Eventually as current consensus present that saola should is been classify as Pseudorygini. Pseudoryx nghetinhensis (Dung, Giao,Chinh, Tuoc, Arctander and MacKinnon, 1993) The saola belongs to the family Bovidae, placing it with cattle and antelopes. The saola differs significantly from all other bovid genera in appearance and morphology. A recent sequencing study of ribosomal mitochondrial DNA of a large taxon sample divides the bovids into two major subfamilial clades. The first clade corresponds to Bovinae and assembles members of the tribes Bovini (cattle and buffaloes), "Tragelaphini" (Strepsicerotini) (African spiral-horned bovids) and "Bosalaphini". The second (Antelopinae) clusters all other bovids, which is composed of Caprini (goats and muskox), Hippotragini (horse-like antelopes), and Antilopini (gazelles). Among these, the saola appears to be most closely associated with the Bovini.[9] The morphology of its horns, teeth and some other features indicate it should be grouped with less-derived or more ancestral bovids.[10]

Habitat and Distribution[edit]

Saola inhabit wet evergreen or deciduous forests in eastern Indochina, preferring rivers and valleys. Sightings have been reported from steep river valleys at 300-1800 m above sea level. In Vietnam and Laos, their range appears to cover approximately 5000 km2, including four nature reserves. During the winters, Saola tend to migrate down to the lowlands.[11]

Behavior and reproduction[edit]

Saolas appear to be mostly solitary, although they have been reported in groups of two or three[4] as well as up to six or seven.[12] Saola grouping patterns resemble other dense vegetation species, such as the bushbuck, anoa, and sitatunga.[12] 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.

Almost all available information on saola behaviour stems from observations of a single captive individual.[7] Captured saola are calm in the presence of humans, allowing themselves to be petted and hand-fed, but display an intense fear of dogs. When they feel threatened, they adopt 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. Saola vocalize with bleats.[7]

Saolas urinate and defecate separately, dropping their hind legs and lowering the lower body, a common behaviour among bovid species. They spend a significant amount of time grooming themselves, making use of their strong tongues.

Very little information is available about their reproductive and pregnancy cycles. Only single-calf pregnancies have been documented so far. Calving occurs in the summer; the saola is likely a seasonal breeder, timing reproduction to coincide with the monsoon, at the very end of the dry season (between mid-April and late June).[8] In the absence of more specific data, the gestation period has been estimated as similar to that of Tragelaphus species (about 33 weeks).[7] Three reports of saola killings from nearby villagers involved young accompanying mothers. One possessed 9.5 cm long horns, another an estimated 15 cm, and the third 18.8 cm; these varying horn lengths suggest a birth season extending over at least 2–3 months.[12]

Diet[edit]

Saola are browsers, as suggested by their relatively undeveloped incisors, and have been reported eating small leafy plants—especially fig leaves and stems—along rivers. While little is known about the full range of their diet, saolas in captivity have subsisted 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.[7] They appear to feed predominantly during daylight and twilight hours.[1]

Conservation[edit]

The saola is currently considered to be critically endangered.[1] Its restrictive habitat requirements and aversion to human proximity are likely to endanger it through habitat loss and habitat fragmentation. Saola suffer losses through hunting for local trophy hunting and the illegal trade in furs, traditional medicines, and for use of the meat in restaurants and food markets.[13] They also sometimes get caught in snares that have been set to catch animals raiding crops, such as wild boar, sambar, and muntjac. More than 26,651 snares have so far been removed from Saola habitats by conservation groups.[14]

The key feature of the area occupied by the saola is its remoteness from human disturbance.[15] Saola are shot for their meat, but hunters also gain high esteem in the village for the production of a carcass. Due to the scarcity, the locals place much more value on the saola than more common species. Because the people in this area are traditional hunters, their attitude about killing the saola is hard to change; this makes conservation difficult. The intense interest from the scientific community has actually motivated hunters to capture live specimens. Commercial logging has been stopped in the nature reserve area of Bu Huong, and there is an official ban on forest clearance within the boundaries of the reserve.[15]

Species of conservation concern are frequently hard to study; there are often delays in implementing or identifying necessary conservation needs due to lack of data.[16] Because the species is so rare, there is a continues lack of adequate data; this is one of the major problems facing saola conservation. Trained scientist have never observed saola in the wild. Unfortunately, because it is unlikely that intact saola populations exist, field surveys to discover these populations are not a conservation priority.[16]

The Saola Working Group was formed by the IUCN Species Survival Commission's Asian Wild Cattle Specialist Group, in 2006[17] 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.[18]

A group of scientists from the Vietnam Academy of Science and Technology in central Hanoi, within the Institute of Biotechnology, investigated a last resort effort of conserving the species by cloning, an extremely difficult approach even in the case of well-understood species.[3] However, the lack of huemul female donors, receptive females and the interspecific barriers greatly compromise the success of cloning technique.[19]

Etymology[edit]

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 the animal 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) [20] In the press, saolas have been referred to as "Asian unicorns",[21] an appellation is apparently due to the saola's rarity and reported gentle nature, and perhaps because both the saola and the oryx have been linked with the unicorn. No known link exists with the Western unicorn myth or the "Chinese unicorn", the qilin.[citation needed]

See also[edit]

Other rarely seen large mammals of the Indochina peninsula, also discovered in the 1990s:

References[edit]

  1. ^ a b c Timmins, R. J.; Robichaud, W. G.; Long, B.; Hedges, S.; Steinmetz, R.; Abramov, A.; Tuoc, D.; Mallon, D. P. (2008). "Pseudoryx nghetinhensis". IUCN Red List of Threatened Species. Version 2013.1. International Union for Conservation of Nature. Retrieved 2013-11-14. 
  2. ^ Grubb, P. (2005). "Order Artiodactyla". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 695. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  3. ^ a b c Stone, R. (2006). "The Saola's Last Stand". Science 314 (5804): 1380–3. doi:10.1126/science.314.5804.1380. PMID 17138879. 
  4. ^ a b Dung, Vu Van; Giao, Pham Mong; Chinh, Nguyen Ngoc; Tuoc, Do; Arctander, Peter; MacKinnon, John (1993). "A new species of living bovid from Vietnam". Nature 363 (6428): 443. doi:10.1038/363443a0. 
  5. ^ "Saola sighting in Vietnam raises hopes for rare mammal's recovery: Long-horned ox photographed in forest in central Vietnam, 15 years after last sighting of threatened species in wild", The Guardian, (November 13 2013).
  6. ^ "Saola Rediscovered: Rare Photos of Elusive Species from Vietnam", World Wildlife Federation (February 13 2013).
  7. ^ a b c d e f g h Robichaud, William G. (1998). "Physical and behavioral description of a captive saola, Pseudoryx nghetinhensis". Journal of Mammalogy 79 (2): 394–405. doi:10.2307/1382970. JSTOR 1382970. 
  8. ^ a b "Saola (Pseudoryx nghetinhensis) - Detailed information." www.ultimateungulate.com. N.p., n.d. Web. 18 April 2013
  9. ^ Hassanin, A.; Douzery, E. J. P. (1999). "Evolutionary affinities of the enigmatic saola (Pseudoryx nghetinhensis) in the context of the molecular phylogeny of Bovidae". Proceedings of the Royal Society B: Biological Sciences 266 (1422): 893. doi:10.1098/rspb.1999.0720. 
  10. ^ Bibi, Faysal; Vrba, Elisabeth S (2010). "Unraveling bovin phylogeny: Accomplishments and challenges". BMC Biology 8: 50. doi:10.1186/1741-7007-8-50. PMC 2861646. PMID 20525112. 
  11. ^ Burgess, Neil (1997). "The Saola Pseudoryx Nghetinhensis in Vietnam -- New Information on Distribution and Habitat Preferences, and Conservation Needs". GreenFile. 
  12. ^ a b c Schaller, George B.; Rabinowitz, Alan (1995-04-01). "The saola or spindlehorn bovid Pseudoryx nghetinhensis in Laos". Oryx 29 (02): 107–114. doi:10.1017/S0030605300020974. ISSN 1365-3008. 
  13. ^ "Saola | Species | WWF." WWF - Endangered Species Conservation World Wide Fund for Nature. N.p., n.d. Web. 24 April 2013
  14. ^ " Home - Saola Working Group ." N.p., n.d. Web. 18 April 2013
  15. ^ a b Kemp, Neville; Dilger, Michael; Burgess, Neil; Dung, Chu Van (2003). "The saola Pseudoryx nghetinhensis in Vietnam - new information on distribution and habitat preferences, and conservation needs". Oryx 31 (1): 37–44. doi:10.1046/j.1365-3008.1997.d01-86.x. 
  16. ^ a b Turvey, Samuel T.; Trung, Cao Tien; Quyet, Vo Dai; Nhu, Hoang Van; Thoai, Do Van; Tuan, Vo Cong Anh; Hoa, Dang Thi; Kacha, Kouvang; Sysomphone, Thongsay (2015-04-01). "Interview-based sighting histories can inform regional conservation prioritization for highly threatened cryptic species". Journal of Applied Ecology 52 (2): 422–433. doi:10.1111/1365-2664.12382. ISSN 1365-2664. PMC 4407913. PMID 25926709. 
  17. ^ "Priorities for Success: 2nd Meeting of the Saola Working Group wraps up in Vietnam". IUCN. 
  18. ^ "Experts on the saola: The "Last chance" to save one of the world's rarest mammals". Scientific American. 
  19. ^ Rojas, Mariana; Venegas, Felipe; Montiel, Enrique; Servely, Jean Luc; Vignon, Xavier; Guillomot, Michel (2005). "Attempts at Applying Cloning to the Conservation of Species in Danger of Extinction". International Journal of Morphology 23 (4): 329–336. doi:10.4067/S0717-95022005000400008. ISSN 0717-9502. 
  20. ^ Tham Ngoc Diep, Dang Thang Long and Do Tuoc, Report on Survey of Saola Pseudoryx nghetinhensis Appendix 3 in Rediscovering the Saola Workshop proceedings, Hanoi 2004
  21. ^ "Rare antelope-like mammal caught in Asia". BBC News. 16 September 2010. Retrieved 16 September 2010. 

Further reading[edit]

  • DeBuys, William The Last Unicorn: a Search for One of Earth's Rarest Creatures ( Little, Brown and Company, 2015)
  • Shuker, Karl P.N. The New Zoo: New and Rediscovered Animals of the Twentieth Century (House of Stratus, 2002).

External links[edit]

Wikimedia Commons has media related to Pseudoryx nghetinhensis.
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