Head and body length: 105-115 cm

Shoulder height: 60-70 cm

Tail length: 15-20 cm

Adult weight: 30-50 kg. Males average 43 kg, females 32 kg.

Hog deer have a stout build with relatively short legs and raised hindquarters. Males are heavier than females, and have much thicker necks. Females are reddish-brown in summer, becoming duller in winter. Mature males are dark brown. An indistinct dark stripe runs along the spine from shoulders to tail. Some adults (especially females) have scattered pale spots in their summer coat (particularly on either side of the darker dorsal line). The underparts are the same color as the back except for the underside of the tail, which is white. Only males grown antlers; these are shed annually. Each antler is three-pronged, with a short brow tine and a terminal fork. Typical antler length for A. p. porcinus is 30-38 cm, and 43-46 cm (with a record of 61 cm) for A. p. annamiticus.

Similar species

• This species resembles the closely-related Calamian deer (Axis calamianensis) and Bawean deer (Axis kuhlii), but hog deer tend to be larger and are easily distinguished by distribution.
• The hog deer is readily distinguished from most other deer species that share its range by its small stature and uniform coloration. The northern red muntjac (Muntiacus vaginalis) is slightly smaller in build, but is rufous in color and has distinctive ridges on the forehead.

Gestation period: 220-230 days.

Litter size: Typically one; twins are known but uncommon.

Weaning: 6 months.

Sexual maturity: 15 months.

Life span: Up to 20 years.

Hog deer breed seasonally, with the peak of rut occuring in September and October in Royal Chitwan National Park (Nepal). Males bellow during courtship. Births coincide with the onset of the dry season (peaking in March-April in Chitwan National Park), when the aftermath of grass fires results in a flush of young, tender shoots. Fawns weigh 2.0-2.74 kg at birth, and are marked with white spots (although populations from Cambodia and Vietnam may lack these). Young spend the first few weeks of life tucked away in dense cover. They begin to accompany their mothers at 4-5 weeks after birth and are independent by one year.

Hog deer are most active in the morning and late afternoon, but nocturnal activity increases in hot temperatures or when they are hunted by humans. Midday is spent resting among tall grasses. Hog deer live in small, overlapping home ranges of 0.11-2.23 km² (averaging ~0.7 km²), with the majority of activity concentrated in a core area of only 0.056-0.358 km². Daily movements rarely exceed 400 m. In favorable grassland habitats, population densities may reach 77.3 animals per km² (recorded in Royal Bardia National Park, Nepal); in Royal Chitwan National Park, densities range from 4.7-35.0 (averaging ~17) hog deer per km². Although typically solitary, hog deer may gather in large groups to feed when young grass shoots are present. When threatened, these groups do not flee as a herd but scatter in different directions. Hog deer seek safety in dense cover, and tend to rush away with their heads held low and their tail elevated, diplaying the white underside. Alarm vocalizations include a whistling call and a sharp bark.

Family group: Generally solitary or in pairs (often mother and offspring). Larger groupings of 40-80 animals may feed together.

Diet: Mostly young grasses, but also young leaves, flowers, and fallen fruit.

Main Predators: Tiger, leopard, and large pythons; young are at risk from many smaller carnivores.

IUCN Red List: Endangered (2012).

CITES Listing: Axis porcinus annamiticus - Appendix I (2013).

Threats: Hunting (primarily for bushmeat), habitat loss due to settlement and agriculture and the subsequent fragmentation of populations.

Hog deer populations have experienced dramatic declines in the past few decades, and now survive only in isolated pockets of suitable habitat. Between 1991 and 2012, hog deer in southeast Asia declined by over 90%, with central Cambodia holding the last remaining scattered populations. Kaziranga National Park (India) is one of the species' strongholds, with a population estimated at 15,000 individuals.