Rusa unicolor

Geographic Range

Cervus unicolor are native to India, Pakistan, Ceylon, Burma, Sri Lanka, Philippines, southern China, Taiwan, Malaysia, Borneo, Sumatra, and Java (Medway, 1969). Sambars have also been successfully introduced in Australia, New Zealand, California, Florida and Texas (Nowak, 1999).

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
• palearctic palearctic
  • native native
• oriental oriental
  • native native
• australian australian
  • introduced introduced

Habitat

Sambars inhabit both gently sloping and steep forested hillsides. They reside preferably near cultivated areas, such as gardens and plantations, in order to acquire food, but are also found in thick forests, swamp forests, and open scrub (Payne et al., 1985). Some of these deer may move between higher altitudes in the summer to lower, more sheltered areas during the winter months (Nowak, 1999).

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest
• scrub forest scrub forest

• Wetlands
• swamp swamp

• Other Habitat Features
• agricultural agricultural

Physical Description

Sambars have a coarse coat of short, dark hair with lighter brown to creamy white hair on their undersides (Tate, 1947). The backsides and undersides of their bushy tails are white, and when raised, the tails are used as signals (Nowak, 1999). Males are generally larger than females and posess a dense mane on their necks. Male Sambars have antlers with three or four tines, and these antlers are periodically shed and replaced. Antlers can reach lengths of up to 100 cm. The maximum size for males is 185-260 kg, and about 162 kg for females (Medway, 1969).

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

• Sexual Dimorphism
• male larger
• ornamentation ornamentation

Reproduction

Male Sambars are solitary and very agressive during the breeding season, while females may be found in groups of up to 8 individuals (Nowak, 1999). Their mating system is polygynous, with one male mating with as many females as he can.

• Mating System
• polygynous polygynous

Sambars have no specific breeding season, but breeding most commonly occurs from September through January. Usually only one fawn is born at a time, and the gestation period is about 9 months. (Medway, 1969). At birth, Cervus unicolor are very active and have brown hair with lighter spots, which are soon lost shortly (Medway,1969). Fawns weigh about 10 kg at birth. Males develop small antlers at one to two years; at three years antlers have two points, and adult males have antlers with three or four points (Payne et al., 1985). Females reach sexual maturity at approximately two years of age (Nowak, 1999). Males are aggressive towards one another during the mating season and actively defend territories, mating with multiple females that enter the area. Males mark their territory with scent glands, and as many as 8 females at a time may remain with one male within his range (Nowak, 1999).

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

Fawns are born weak but able to walk. They remain with their mother for 1-2 years.

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

Lifespan/Longevity

In captivity, Cervus unicolor can live for over 26 years, but in the wild the average lifespan is about 20 years (Nowak, 1999).

Behavior

Sambars are mostly nocturnal, resting during the day in heavy forest cover (Medway, 1969). These deer are solitary but may be found in small groups during the mating season. Also, groups of up to 6 females with dependent young may travel together (Payne et al., 1985). Males are nomadic and establish territories primarily during breeding seasons. All sambars are proficient swimmers (Nowak, 1999).

• Key Behaviors
• cursorial
• terricolous
• nocturnal nocturnal
• crepuscular crepuscular
• motile motile
• nomadic nomadic
• solitary solitary
• territorial territorial
• social social

Communication and Perception

• Perception Channels
• tactile tactile
• chemical chemical

Food Habits

Sambars generally feed at dusk or at night, and they browse on leaves, berries, grasses, bark from young trees, fallen fruit, herbs and buds. They browse mainly at clearings and forest edges (Payne et al., 1985).

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves
• wood, bark, or stems
• fruit

Predation

Sambars have developed a crepuscular and nocturnal activity pattern in response to hunting pressures from humans (Payne et al., 1985).

Ecosystem Roles

Sambar may disperse seeds as they forage.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Humans hunt Cervus unicolor for food and for trade. Sambars are also captured and placed into zoos worldwide.

• Positive Impacts
• food food
• body parts are source of valuable material
• ecotourism ecotourism

Economic Importance for Humans: Negative

Sambars may damage agricultural crops when they forage near human habitation.

• Negative Impacts
• crop pest

Conservation Status

Although global population data is not known, the population in India exceeds 50,000 and in Australia Sambars number more than 5,000 individuals.

Other Comments

Several subspecies are recognized, including Rusa unicolor equinus , Rusa unicolor unicolor , Rusa unicolor brookei , and Rusa unicolor dejeani . Sambars were previously considered a member of the genus Cervus , as Cervus unicolor .

Additional Links

Encyclopedia of Life

Contributors

Christine Brown (author), University of Michigan-Ann Arbor, Ondrej Podlaha (editor), University of Michigan-Ann Arbor.

References

CITES Secretariat, 2001. "Convention on International Trade in Endangered Species of Wild Fauna and Flora" (On-line). Accessed November 18, 2001 at www.cites.org .

Medway, L. 1969. The Wild Mammals of Malaya . London: Oxford University Press.

Nowak, R. 1999. Walker's Mammals of the World, 6th ed. . Baltimore and London: The Johns Hopkins University Press.

Payne, J., C. Francis, K. Phillipps. 1985. A Field Guide to the Mammals of Borneo . Malaysia: The Sabah Society with WWF Malaysia.

Tate, G. 1947. Mammals of Eastern Asia . New York: The Macmillan Company.

The World Conservation Union, 2000. "2000 IUCN Red List of Threatened Species" (On-line). Accessed November 18, 2001 at www.redlist.org .