The Northern pig-tailed macaque (Macaca leonina) is a species of macaque in the family Cercopithecidae. It was considered a subspecies of the Southern pig-tailed macaque but is now classified as individual species.
Northern pig-tailed macaques have a round greyish pelage from the side of their cheeks all the way around to the top of their head and beneath their chin, which is called a crown. A brown pelage patch is found on the center of their crowns followed by white triangular forms beneath this patch and along the top of their eyes. One red stripe is found at each exterior corner of their eyes which are angled upwards and diagonally meeting at the ending point of the white triangular eye extremities. On their backs, for mostly males, a black streak is found at the center; and can sometimes have a red hue towards the top and black towards the bottom. Moving downwards, their tails are composed of a thin pelage in a dark blackish hue and are shorter and skinner than southern pig-tailed macaques. Beneath their tail, on their backside, there are oval-shaped thick sitting pads that cover their hip bones, known as ischial callosities. Adult males are identified with defined shoulder musculature and their tails are also found to be longer relative to females and their pelage has darker contrast to it.
Northern pig-tailed macaques are found in Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand, and Vietnam. They inhabit forests with higher elevations, more specifically broadleaved evergreen forests, primary and secondary forests, deciduous forests, cloud forests, riparian areas, coastal forests, swamp forests, and low-elevation forests.
Northern pig-tailed macaques are arboreal and diurnal animals. They live in matriarchal groups which can be sedentary or nomadic. Groups are fairly large and can exceed over 150 individuals. However, they split into smaller groups when feeding and rejoin for larger group travel. They are also found to vary their home range depending on the season, as the fruit availability and quality varies. In low fruit abundance periods, Northern pig-tailed macaques may travel to human settlements to feed on fruits from plantation forests when wild ones are scarce. Their home range, however, increases as a result of high fruit abundance periods, where they are found settling near specific fruit species within forest habitats. Therefore, they use different strategies to forage for food depending on what environments show abundance or low abundance, and their seasonality.
Northern pig-tailed macaques are mainly frugivorous as they tend to forage for hundreds of fruit species such as fleshy and dry; as well as flowers and buds, piths, leaves, and shoot species that makeup a big part of their diet. Due to limited fruit availability in colder seasons or with habitat degradation, they may become more omnivorous and eat fungi, ants, termites, spiders, stickbuds, grasshoppers, caterpillars, beetles, mushrooms, barks, eggs, lizards, and squirrels.
Northern pig-tailed macaques breed throughout the year. Females give birth to a single infant after a gestation period that exceeds the eight-month period and nurse their offspring up to two years of age.
The main threats to this species include habitat loss and forest fragmentation due to agricultural expansions, aquaculture, and transportation infrastructure, hunting and logging for meat and trophies, and the illegal pet trade. Northern pig-tailed macaques were also observed as the highest-kept macaque out of the range of captive macaque species in Vietnam; they were found in various locations from cages on personal property to hotels and restaurants. Viruses are another common threat among Northern pig-tailed macaques that inhabit degraded environments.
The IUCN Red List and other sources don’t provide the number of the Northern pig-tailed macaque total population size. However, there are estimated populations in the following areas: 1,700 individuals in China and less than 1,500 individuals in India. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List, and its numbers today are decreasing.
Northern pig-tailed macaques are important seed dispersers throughout their native range and thus help in forest regeneration.
