Sambar deer

Though they mate and reproduce year-round, sambar calving peaks seasonally. Oestrus lasts around 18 days. The male establishes a territory from which he attracts nearby females, but he does not establish a harem. The male stomps the ground, creating a bare patch, and often wallows in the mud, perhaps to accentuate the colour of his hair, which is typically darker than that of females. While they have been heard to make a loud, coarse bellow, rutting stags are generally not vocal.[5] Large, dominant stags defend nonexclusive territories surrounded by several smaller males,[9] with which they have bonded and formed alliances through sparring. When sparring with rival males, sambar lock antlers and push, like other deer, but uniquely, they also sometimes stand on their hind legs and clash downward into each other[7] in a manner similar to species of goat-antelope. Females also fight on their hind legs and use their fore legs to hit each other in the head.[5]

A sambar hind with a young stag

Courtship is based more on tending bonds rather than males vocally advertising themselves.[7] Females move widely among breeding territories seeking males to court.[5] When mounting, males do not clasp females. The front legs of the male hang loosely and intromission takes the form of a "copulatory jump".[7][9]

Gestation probably lasts around 8 months, although some studies suggest it may be slightly longer. Normally, only one calf is born at a time, although twins have been reported in up to 2% of births. Initially weighing 5 to 8 kg (11 to 18 lb), the calves are usually not spotted, although some subspecies have light spots which disappear not long after birth.[5] The young begin to take solid food at 5 to 14 days, and begin to ruminate after one month.[12] Sambar have lived up to 28 years in captivity, although they rarely survive more than 12 years in the wild.[5]

The subspecies of the sambar in India and Sri Lanka are the largest of the genus, with the largest antlers both in size and in body proportions. The South China sambar of Southern China and mainland Southeast Asia is probably second in terms of size, with slightly smaller antlers than the Indian sambar. The Sumatran sambar that inhabits the Malay Peninsula and Sumatra and the Bornean sambar seem to have the smallest antlers in proportion to their body size. The Formosan sambar is the smallest subspecies, with antler-body proportions more similar to the South China sambar.

Currently, seven subspecies of sambar are recognised,[5][14] although many others have been proposed.

Subspecies	Common name	Geographic range
R. u. boninensis↑[15]	Bonin sambar	the Bonin Islands (extinct)
R. u. brookei	Bornean sambar	Borneo
R. u. cambojensis	Mainland Southeast Asian sambar	Mainland Southeast Asia
R. u. dejeani	South China sambar	southern and southwestern China
R. u. equina	Malayan sambar	Sumatra
R. u. hainana	Hainan sambar	Hainan, China
R. u. swinhoii	Formosan sambar	Taiwan
R. u. unicolor	Sri Lankan sambar or Indian sambar	India, Bangladesh, Sri Lanka

In Australia, hunting sambar is a popular sport. Australian hunting fraternities prize large sambar trophies.[17] Excessive numbers of sambar affect native plants, threatening some species with extinction.

Sambar were introduced into Victoria at Mount Sugarloaf in the 1860s, in what is now Kinglake National Park, and at Harewood Estate near Tooradin.[18] They quickly adapted to the Koo-Wee-Rup Swamp and thereafter spread into the high country, where in 2017, numbers were estimated at between 750,000 and one million animals.[19] Later releases were at Ercildoune Estate near Ballarat, Wilsons Promontory, and French Island in Western Port. Another release occurred on the Cobourg Peninsula in the Northern Territory.[20] They are now found throughout Australia's northern and eastern coasts, in the states of Victoria, South Australia, Queensland, the Northern Territory, and the Australian Capital Territory.

In Victoria, sambar have been listed as a threat to biodiversity under the Flora and Fauna Guarantee Act 1988 because they reduce the number of native plant species.[21] The animals feed on some rare and endangered plants. More than 60 plant species have been identified as directly or indirectly threatened by sambar within Victoria.

Adult male sambar can significantly damage plants, removing most branches on some shrubs and sometimes girdling trees by thrashing their antlers on shrubs and sapling trees. They also feed on seedlings, fruit, or seeds of many plants. They leave territorial marks to advertise their territory.[22]

The spread of sambar has been steady in both New South Wales and Victoria, with animals being seen on many southern Victorian beaches since 1980, and as far east as Western Port and the outer suburbs of Melbourne.

Considerable debate exists about how they should be managed. Conservation groups believe their environmental effect outweighs their social value. Hunting organisations disagree and want to preserve sambar populations for future generations. Sambar are protected wildlife game species in Victoria and New South Wales, and a game licence is required to hunt them. In Victoria, recent provisions have been made for landowners to control problem deer without having to obtain a Game Licence or Authority to Control Wildlife permit.[23] This allows a landowner or other authorised persons to remove problem deer within private property at any time and with no bag limits. They are declared a pest species in all other Australian states and territories and can be hunted at any time with no bag limits. Environmental and conservation groups want them declared a feral species in all states, due to their exploding populations and the harm to biodiversity and native species.

In 2008/2009, hunters removed 35,000 sambar from public land in Victoria, many from national parks. This is a small fraction of the 40% of individuals in a sambar population that need to be removed to stop population growth.[24]

In New Zealand, sambar roam the coast and gullies in Horowhenua District, Manawatu District, Rangitikei, and Whanganui. Until recently, they were protected, but the Department of Conservation has now removed hunting regulations surrounding them, allowing them now to be hunted year round.[25]

Sambar were introduced onto St. Vincent Island, Florida, in 1908[26] and increased to about 50 individuals by the 1950s. White-tailed deer also live on St. Vincent Island; however, they inhabit the highlands while the sambar mostly live in the lowlands and marshes. To ensure that the sambar population does not disrupt the native white-tails, hunting permits have been issued since 1987 to regulate the population. Each year, about 130 permits are offered for the three-day hunt. This maintains a sambar population of 70–100 individuals.[27] They do not herd, but occur in groups of four or five animals, possible family groups. Little is known about the sambar in Florida.[28]