Pseudoryx nghetinhensisSaola(Also: Vu Quang ox)

Geographic Range

Pseudoryx nghetinhensis is found in few mountainous areas of Vietnam and Laos PDR (People's Democratic Republic), near the Lao PDR and Vietnam border. Saola have one of the smallest ranges of mammals in the world, and are found in only 6 provinces in Vietnam and 3 provinces in Laos PDR. (Robichaud, 1998; Duckworth, et al., 1999; Dung, et al., 1993; Robichaud, 1998)

Habitat

Saola prefer broadleaf evergreen forests that are in the wet lowland Annamite Mountains of Laos PDR and Vietnam, including marshes and swamps. They are found at elevations between 400 and 750 m. The habitat has long rainy seasons with high average annual rainfall (Hardcastle, et al., 2004; Kemp, et al., 1997)

  • Range elevation
    400 to 750 m
    1312.34 to 2460.63 ft

Physical Description

Saloa are large animals, measuring around 150 cm and weighing in between 80 and 100 kg. Although not reported for soala, sexual dimorphism is common in bovids, and may occur in this species.

Both males and female saola have horns that are probably used for protection against predators. The common name, saola, means "spinning wheel posts" in the local language. This name was probably given to the species because of the way the horns resemble tapered posts of a spinning wheel.

These animals have brown noses. The pelage consists of different shades of brown. Some have white patches on the side of neck. A black stripe extends from the shoulders to the lower back. The underside of is a lighter shade of brown than the upper body. The tail is striped, with brown, black, and cream colors. The rump is marked by a cream colored band which extends horizontally from the top of one hind leg to the other. White bands encircle the lower leg, just above the hooves. The face has white patches that conceal small dermal nodules that may be scent glands. Saola have possibly the largest maxillary glands of any living mammal. (Dung, et al., 1993; Hardcastle, et al., 2004)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    80 to 100 kg
    176.21 to 220.26 lb
  • Average length
    150 cm
    59.06 in

Development

Little is known about the development of saola

Reproduction

Mating takes place between August and November. It is unknown if saola exhibit any mating rituals. (Hardcastle, et al., 2004; Robichaud, 1998)

There is little information available on the mating systems of saola, but estimations were made from examining a dead pregnant female. Saola give birth between April and June. It is not known whether saola use their horns as display for mating purposes. They are similar to other Bovinae, like four-horned antelope, in that gestation lasts 8 months. Saola only have one offspring per litter.

Other information on reproduction in this species is not available. These animals were only recently recognized as a species, and are quite rare. (Hardcastle, et al., 2004; Robichaud, 1998)

  • Breeding interval
    Saloa appear to breed once per year.
  • Breeding season
    Breeding apparently takes place between August and November.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average gestation period
    8 months

There is little information available on parental investment of saola, although Artiodactyl young are generally precocious. Like other members of the family, it is likely that most parental care is provided by the mother. Young receive nourishment from mother's milk, protection from mother, and probably some form of grooming. It has not been reported how long young are dependent upon the mother, although if soloa are like other members of the family, it is likely to be around one year.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Little is known about the life span in the wild, but in captivity, saola generally do not survive greater than 5 months. This is probably due to stress and lack of proper nutrition. Other members of the subfamiliy Bovinae can live 15 to20 years in the wild, and it is likely that this species is similar. ("Animal Fact Sheets", 2004; Robichaud, 1998)

Behavior

Although there are currently no studies on saola behavior in the wild, observations have been made on captive saola. These animals seem to be active both at night and during the day, although some familiar with saola report that wild iondividuals are mostly active in the morning and late afternoon. Soala appear to be solitary animals. They also seem to engage in territorial marking by snapping small saplings with their horns. Since their horns have many scratches, it is suggested that they rub vegetation and soil as a part of social or sexual activity. The putative scent glands on the face of saloa may indicate some scent marking of territories. (Hardcastle, et al., 2004; Robichaud, 1998)

  • Range territory size
    unknown to 4000 km^2

Home Range

Saola tend to stay close to the Vietnam-Lao PD border, in the wet evergreen areas on the Annamite Mountains. Their geographic range is small (4000 sq km) and their home range is undetermined. (Dung, et al., 1993; Kemp, et al., 1997; Robichaud, 1998)

Communication and Perception

Saola in captivity have been observed bleating for unknown reasons. Some researchers suggest that twig breaking with horns may be a form of social and/or sexual communication. They also possess scent glands under the white markings on their faces, indicating the importance of chemical communication in this species. Although not specifically reported, we can infer that tactile communication is important during mating and rearing of young. Because these animals might have some activity during daylight hours, there may also be visual communication between individuals based on body postures and other visual signals. (Robichaud, 1998)

Food Habits

Saola are herbivores, primarily eating ferns and flowering plants (angiosperms). (Robichaud, 1998)

  • Plant Foods
  • leaves
  • flowers

Predation

Natural predators of saola are tigers, leopards, and dholes although humans are the major predator of saola and threaten their existence. When threatened, saola use their sharp-tipped horns for protection from predators by lowering their heads to strike the predator. Although they don't appear to be frightened by humans, saola are terrified of dogs. While running from predators, their glands swell and they snort. (Robichaud, 1998; Robichaud, 1998; Hardcastle, et al., 2004; Robichaud, 1998)

Ecosystem Roles

Not much is known about the role saola play in the ecosystem. Since there are few saola, they probably do not greatly impact the surrounding vegetation. Although they provide potential prey to carnivorous mammals, because they are so rare it is unlikely that saola are important in local food webs.

Economic Importance for Humans: Positive

Saola are one of the many animals that are hunted in Vietnam and Lao PDR for meat and hide. (Robichaud, 1998)

  • Positive Impacts
  • food
  • body parts are source of valuable material
  • research and education

Economic Importance for Humans: Negative

There is no known adverse affects of saola on humans.

Conservation Status

Saola are listed as endangered. The primary threat to these animals is hunting and loss of their forest habitat due to agriculture and logging. Locals place a high value on saola because of their scarcity. Many hunters also try to capture live saola because of their importance to the scientific community. Saola don't do well in captivity, and die soon after capture. Intense conservation efforts were started in 1997 to ensure the survival of these creatures. (Kemp, et al., 1997; Robichaud, 1998)

Other Comments

Pseudoryx nghetinhensis was the first new large mammal to be discovered in over 50 years. This is probably because its habitat is difficult to access, the elusive behavior of saola, and political reasons. Through further study of this species we can hopefully come to understand saola better and help these rare animals to survive and thrive in Asia. Other species recently discovered in Vietnam and Laos PDR are Megamuntiacus vuquangensis (muntjak deer) and Lophura hatinhensis (pheasant).

Saola are large mammals that resemble antelope, (family Bovidae and subfamily Antilopinae). Although they were first thought to be more closely related to members of the subfamily Caprinae (which includes chamois, goats, sheep, and others), DNA evidence has recently placed them in the subfamily Bovinae ( which includes bison, buffalo, and cattle). (Kemp, et al., 1997; Robichaud, 1998; Weitzel, 2004)

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Link Olson (editor, instructor), University of Alaska Fairbanks, Darce Holcomb (author), University of Alaska Fairbanks.

Glossary

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

2004. "Animal Fact Sheets" (On-line). Accessed December 08, 2004 at http://www.zoo.org/educate/fact_sheets/anoa/anoa.htm.

Duckworth, J., R. Salter, K. Khounboline. 1999. Wildlife in Lao PDR: 1999 Status Report. Vientiane: IUCN- The World Conservation Union/ Wildlife Conservation Society/Centre for Protected Areas and Watershed Management: 1-275. Accessed November 16, 2004 at http://wcs.org/sw-around_the_globe/Asia/laos/wildlifeinlaopdr.

Dung, V., P. Giao, N. Chinh, D. Tuoc, P. Arctander. 1993. A new species of living bovid from Vietnam. Nature, 363: 443-445.

Gatesy, J., P. Arctander. 2000. Hidden morphological support for the phylogenetic placement of Pseudoryx nghetinhensis with bovine bovids: a combined analysis of gross anatomical evidence and DNA sequences from five genes. Systematic Biology, 49/3: 515-538.

Hardcastle, J., S. Cox, N. Thi Dao, A. Johns. 2004. Rediscovering the Saola. Proceedings of the "Rediscovering the saola- a status review and conservation planning workshop": 1-115. Accessed November 14, 2004 at http://www.panda.org/downloads/ecoregions/saolaproceedingenglish.pdf.

Kemp, N., M. Dilger, N. Burgess, C. Dung. 1997. The saola Pseudoryx nghetinhensis in Vietnam- new information on distribution and habitat preferences, and conservation needs. Oryx, 31/1: 37-44.

Robichaud, W. 1998. Physical and behavioral description of a captive saola, Pseudoryx nghetinhensis . Journal of Mammalogy, 79/2: 394-405.

Weitzel, V. 2004. "Australia Vietnam Science Technology Link" (On-line). New species in Vietnam. Accessed December 09, 2004 at http://coombs.anu.edu.au/~vern/species.html.