Northern pig-tailed macaque
The Northern pig-tailed macaque (Macaca leonina) is a medium-sized Old World monkey of the family Cercopithecidae, distinguished by its short, upward-curving tail, golden-brown fur, and dark facial skin with reddish streaks extending from the eyes.[1][2] Males typically weigh 7-9 kg and measure up to 58 cm in head-body length, while females are smaller at 4-6 kg.[2] Native to Southeast Asia, it ranges from northeastern India and Bangladesh through Myanmar, Thailand, Laos, Cambodia, Vietnam, and into southern China.[3] This diurnal, predominantly arboreal species inhabits a variety of tropical forest types, including primary and secondary evergreen forests, mixed deciduous forests, dry dipterocarp woodlands, and riparian zones, often from sea level up to elevations exceeding 2,000 m.[1][3] Omnivorous and opportunistic, its diet centers on fruits and seeds, supplemented by leaves, flowers, insects, and small vertebrates, enabling it to contribute significantly to forest regeneration through seed dispersal.[3] Socially organized in multimale-multifemale groups of 10-50 individuals, it exhibits flexible behaviors adapting to habitat degradation, though populations have declined markedly due to habitat fragmentation from logging and agriculture, as well as direct persecution via hunting for bushmeat, pets, and biomedical research.[4][1] Assessed as Vulnerable on the IUCN Red List since 2008, the Northern pig-tailed macaque faces ongoing threats that have reduced its numbers by at least 30% over three generations, with regional variations including Endangered status in India and Critically Endangered in Bangladesh.[5] Conservation efforts emphasize protected areas and anti-poaching measures, yet enforcement challenges and human-primate conflict persist in fragmented landscapes.[4]Taxonomy
Classification and phylogeny
The Northern pig-tailed macaque (Macaca leonina) is classified within the order Primates, suborder Haplorhini, infraorder Simiiformes, parvorder Catarrhini, superfamily Cercopithecoidea, family Cercopithecidae, subfamily Cercopithecinae, and genus Macaca.[6][1] The species was formally described by Edward Blyth in 1863 based on specimens from regions including present-day Bangladesh and Myanmar.[7] It is recognized as monotypic, lacking recognized subspecies, following revisions that elevated it from prior synonymy or subspecific status under M. nemestrina.[8][9] Phylogenetic analyses of mitochondrial genomes position M. leonina within the diverse genus Macaca, which comprises approximately 22 species divided into monophyletic groups including the silenus, sinica, fascicularis, and nemestrina-assarctoides clades.[10] Within the pig-tailed macaque complex, M. leonina (northern form) shares a recent common ancestry with southern congeners such as M. nemestrina and M. pagensis, with Bornean lineages (M. pagensis) representing the earliest divergence among examined pig-tailed populations.[11][11] This topology reflects historical dispersal events across mainland and island Southeast Asia, driven by Pleistocene sea-level fluctuations and habitat connectivity, rather than deep vicariance.[11] Nuclear and mitochondrial markers further confirm M. leonina's distinct evolutionary trajectory, supporting its species-level separation via accumulated genetic and morphological divergences, including cranial and pelage traits documented in foundational taxonomic revisions.[9] The nemestrina group, encompassing pig-tailed species, clusters closely with the fascicularis group in broader macaque phylogenies, indicative of shared Southeast Asian origins predating the genus's radiation across Asia and North Africa.[10]Physical description
Morphology
The Northern pig-tailed macaque (Macaca leonina) exhibits a stocky, thick-set build typical of medium-sized Old World monkeys, with a broad chest and relatively long legs that support both arboreal and terrestrial locomotion. When standing quadrupedally, adults measure 40–65 cm in head-body length, complemented by a short, thick tail of 14–25 cm that is often arched or curled over the back, giving the species its distinctive "pig-tailed" appearance.[3][1] Body weights vary, generally ranging from 4.4 to 14.5 kg across individuals, reflecting environmental and nutritional influences observed in wild populations.[3][1] The pelage consists of coarse, olive-gray to golden-brown fur, denser on the dorsal surface and forming a darker brown crown on the head, which lightens with age from the darker natal coat of juveniles. Facial skin is pinkish and largely naked, featuring pale patches around the eyes, prominent red streaks extending from the outer eye corners toward the ears, and exaggerated cheek ruffs particularly in mature individuals. Ischial callosities and genital regions display a darker red hue, while the overall morphology includes a moderately long snout and robust limbs adapted for foraging in varied forest strata.[3][1]Sexual dimorphism
The Northern pig-tailed macaque (Macaca leonina) exhibits moderate sexual dimorphism, primarily in body size and mass, with adult males substantially larger than females. This size difference is characteristic of many macaque species and correlates with male-male competition for mating opportunities.[3]| Trait | Males | Females |
|---|---|---|
| Head-body length | 50–60 cm | 40–49 cm |
| Tail length | 16–25 cm | 14–20 cm |
| Weight | 6.2–9.1 kg | 4.4–5.7 kg |