Northern pigtail macaque  (Macaca leonina)

Classified as Vulnerable (VU A1cd) on the IUCN Red List 2004 (1). Previously considered a subspecies of Macaca nemestrina, under which it is listed on Appendix II of CITES (3).

As its name suggests, this macaque is characterised by its short, ‘pig-like’ tail, which it normally carries in an erect backward arch over the back, with the tip partially resting on the rump. This species resembles the Sunda pig-tailed macaque (Macaca nemestrina), but is smaller in size and has comparatively short limbs and face. The macaque possesses a relatively long, uniformly agouti golden-brown coat, with markings confined only to the brown crown, buff-coloured cheek whiskers and the red streak extending from the outer corner of each eye. A distinct tuft of hair also exists at the end of the tail. Young are a blackish colour when born, but juveniles are rather more brightly coloured than adults (2).

Eastern Bangladesh, Cambodia, China (Yunnan), India (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura), Laos, Myanmar (including the Mergui Archipelago), Thailand, and southern Vietnam. There is an additional, introduced population on the Andaman Islands (India) (2).

Found in lowland primary and secondary forest, as well as coastal, swamp and montane forest. Dense rainforest is preferred, but agricultural lands may also be occupied. Groups often sleep in dipterocarp trees (2).

This diurnal species occupies all levels of the forest canopy and also spends much of its time foraging on the ground. Fruits and seeds form the bulk of the diet, together with young leaves, buds, shoots, fungus and animal prey (including insects, river crabs and nesting birds). As an opportunistic feeder (4), however, this macaque also has a tendency to raid crops such as corn, papaya, oil palm and grain, earning it a reputation as a serious pest over much of its range (2).

The northern pigtail macaque lives in multi-male / multi-female groups of 5 to 40 (average 15 to 22), with around five to eight females to every male. Females remain with their natal group, which is structured by a matrilineal dominance hierarchy. By contrast, males disperse at puberty and remain solitary or peripheral to a group. Mating occurs year-round, although a reproductive peak occurs between January and May. Females have a 30 to 35-day reproductive cycle, and display an enormous, purplish-pink genital swelling at oestrous (2). These swellings provide a visual cue to males that the female is about to ovulate, and adult males rarely attempt to copulate otherwise (4). Mating is initiated by the male, whose courtship approach involves retracting the ears and pushing the lips forward (2). Since mates are usually familiar with each other within a group, cercopithecines (guenons, macaques and baboons) typically display only minimal courtship behaviour, confined to signals that indicate an immediate readiness to mate (4). Single offspring are born after a gestation period of 162 to 186 days, and the young are then nursed for 8 to 12 months. Juveniles reach sexual maturity at around four years (2).

Macaques are used extensively in animal testing and vivisection, often being trapped in the wild or captive bred in poor conditions (5), and this species is no exception. Pig-tailed macaques are very popular for use in laboratories, being almost ideally suited for both psychological studies and HIV research. Threatened also by loss of habitat, the species is declining rapidly in many areas across its range. The macaque’s taste for agricultural crops has also deemed it a pest, and it is therefore frequently shot on sight (2). Sadly, as its forest habitat is destroyed, the species is likely to become ever more dependent upon such crops for food.

The northern pigtail macaque is known to occur in 26 protected areas across its range (2), but there are currently no dedicated conservation efforts that target this species.

View information on this species at the UNEP World Conservation Monitoring Centre.