Siola, Vu Quang ox, Spindlehorn, Asian unicorn, the Vu Quang bovid, Vu quang bovid

Pseudoryx nghetinhensis
Population size
Bnelow 750
Life Span
8-10 years
Top speed
km/h mph 
kg lbs 
cm inch 

The saola (Pseudoryx nghetinhensis) is one of the world's rarest large mammals, a forest-dwelling bovine native to the Annamite Range in Vietnam and Laos. It was described in 1993 following the discovery of remains in Vũ Quang Nature Reserve by a joint survey of the Vietnamese Ministry of Forestry and the World Wide Fund for Nature. Saolas have since been kept in captivity multiple times, although only for short periods as they died within a matter of weeks to months. The species was first reported in 1992 by Do Tuoc, a forest ecologist, and his associates, and a living wild saola was first photographed in 1993 in captivity, and last photographed in 2013 by a movement-triggered camera in the forest.


Saola has a chocolate brown coat with patches of white on the face, throat, and sides of the neck. There is a paler shade of brown on the neck and the belly, and a black dorsal stripe. Saola skin is 1-2 millimeters (0.039-0.079 in) thick over most of the body but thickens to 5 millimeters (0.20 in) 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. The saola has round pupils with dark-brown irises that appear orange when light is shone into them; a cluster of white whiskers about 2 centimeters (0.79 in) long with a presumably tactile function protruding from the end of the chin. Both sexes possess slightly divergent horns that are similar in appearance and form almost the same angle with the skull but differ in their lengths. Horns resemble the parallel wooden posts locally used to support a spinning wheel (thus the familiar name "spindlehorn"). These are generally dark brown or black and about 35-50 cm long; twice the length of their head.




Biogeographical realms

Saola inhabit wet evergreen or deciduous forests in eastern Indochina, preferring rivers and valleys. During the winters, these animals tend to migrate down to the lowlands.

Saola habitat map

Climate zones

Saola habitat map

Habits and Lifestyle

Saola are active during the day as well as at night but prefer resting during the hot midday hours. They are generally solitary creatures but may gather in groups of 2 or 3 as well as up to 6 or 7 individuals. Saola are territorial and mark their territories by opening up the flap of the maxillary gland and leaving a pungent secretion on rocks and vegetation. When not foraging saola spend considerable time grooming themselves, resting, and occasionally give out short bleats.

Seasonal behavior

Diet and Nutrition

Saola are herbivores (folivores) and feed on leaves of trees and bushes, that grow along rivers.

Mating Habits

late August to mid-November
33 weeks

Very little information is available about the reproductive cycle of saola. They have a fixed mating season that lasts from late August to mid-November. Females give birth to only a single calf, mainly during summer between mid-April and late June. The gestation period is thought to last about 33 weeks.


Population threats

The biggest threats to saola are habitat loss and habitat fragmentation. They also suffer from local hunting and the illegal trade in furs, traditional medicines, and for use of meat in restaurants and food markets. Saola 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. Due to the scarcity, the locals place much more value on the saola than on more common species. Because the people in this area are traditional hunters, their attitude about killing saola is hard to change and this makes conservation difficult.

Population number

According to the IUCN Red List, the total population size of the saola is less than 750 individuals. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List, and its numbers today are decreasing.

Fun Facts for Kids

  • The saola is related to cattle, goats, and antelopes.
  • The saola was described in 1992 and has 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).
  • The name 'saola' is translated as "spindle(-horned)", although the precise meaning is actually "spinning-wheel post horn". The name comes from the Tai language of Vietnam.
  • Hmong people in Laos call saola as saht-supahp. This term is derived from Lao and means "the polite animal" because saola move quietly through the forest.
  • Other names used by local people in the Saola's range are lagiang (Van Kieu), a ngao (Ta Oi), and xoong xor (Katu).
  • In the press, saola have been referred to as "Asian unicorns", apparently due to their rarity and reported gentle nature, and perhaps because both the saola and the oryx have been linked with the unicorn.


1. Saola on Wikipedia -
2. Saola on The IUCN Red List site -

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