The family Tragulidae (mouse deer or chevrotains) is one of a number of families in the mammal order Artiodactyla (the even-toed ungulates). Tragulidae is the sole family in the artiodactyl infraorder Tragulina, a lineage that diverged from the other artiodactyl ruminants early in their evolution. Meijaard (2011) recognized 10 species of tragulids, placed in three genera (Moschiola, Tragulus, and Hyemoschus). Tragulids are small, secretive ungulates now found only in the tropical forests of Africa, India, Sri Lanka, and Southeast Asia. The African Water Chevrotain (Hyemoschus aquaticus) is the only tragulid found outside Asia. Two of the three Moschiola species are endemic to Sri Lanka.
Tragulids resemble small, hornless deer with small heads, tapered snouts, slender legs, and stocky bodies. They have large eyes, slit-like nostrils, and medium-sized rounded ears covered with a thin layer of hair. Their backs are rounded and rise toward the rear. This body shape helps them move through dense forest undergrowth. In all tragulid species, the darker base colors contrast with patterns of white and brown spots and stripes on the neck, throat, chest, sides, and underbelly, giving the animal a speckled appearance that provides camouflage in the sun-speckled undergrowth of the dense tropical and subtropical forests in which they live. To escape predators, at least some tragulids take to water.
Tragulids lack antlers, but males sometimes use their enlarged, curved upper canines for fighting with each other over females. Tragulids are mainly solitary, usually interacting only to mate. Unlike most other artiodactyls, tragulids apparently cannot rise on their hind legs. Tragulids have a mainly plant-based diet and, unusually for artiodactyls, at least some species are largely frugivorous.
Only one tragulid species, Balabac Chevrotain (Tragulus nigricans), is listed as Endangered on the IUCN Red List. Some other species, however, have very limited distributions(e.g., Silver-backed Chevrotain [T. versicolor] in Vietnam, Northern Chevrotain [T. williamsoni] in northern Thailand (and possibly Laos) and southern China, and the Sri Lankan Moschiola species. Javan Chevrotain (T. javanicus) has lost much of its former lowland habitat and may now have a very restricted range.
Many tragulids are hunted for their meat, usually with traps or dogs.
(Meijaard 2011 and references therein)
