Sambar Deer are active at night or dusk. The male Sambar is among the largest of Southeast Asian deer. It is solitary, very territorial and aggressive during the breeding season. The male is also polygynous, during mating season they will mate with as many females as he can. Females live in small herds of only 3 or 4 individuals an adult female, her most recent young, and one or two subordinate, immature females.