Northern pig-tailed macaque

Northern pig-tailed macaque. Photograph: Author.

Northern pig-tailed macaque. Scientific name- Macaca leonina. This species is globally vulnerable and critical endangered in Bangladesh. During my recent visit to Shatchori National Park in Habiganj, Bangladesh I have observed this species very closely and very carefully. There are many more females per group than males.

Around 20-30 group members are dominated by one male. Old females are use to take care the entire group. These small gangs use to stays together and move together. Few team members are close observer for any threat around, and if found they made an alarming sound for the entire group for their cautiousness.

The northern pig-tailed macaque is a species of macaque in the family Cercopithecidae. It is found in Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand and Vietnam. Traditionally, M. leonina was considered a subspecies of the southern pig-tailed macaque (M. nemestrina), but is now classified as individual species.

The Northern Pig-tailed Macaque lives in lowland and hilly rainforests but is more terrestrial than arboreal. It lives in large social groups of up to 80 individuals and travels vast distances while foraging. It is highly frugivorous and as such, is an essential seed disperser. It gets its name from its short pig-tail which it carries in an arch over its back resting on its rump.

The Northern Pig-tailed Macaque can be distinguished from its southern cousin by the diagonal lines which extend up from the corner of each eye. It has a long golden-brown coat with a brown crown and buff-colored cheek whiskers. This species is shy in nature and prefers the shelter of dense forests. This macaques lives approximately 26 years in the wild and in captivity lives 35 years.

Northern pig-tailed macaques are large, thick-set monkeys with an olive-gray pelage that forms a darker brown crown on their heads. When standing quadrupedally, their broad chest and comparatively long legs mean they have an almost box-like shape. They have pinkish faces with patches of pale skin around the eyes and distinctive red lines extending from the outside corners of the eyes to the edge of the face.

They have long hairs on their cheeks (the cheek ruff), which are especially prominent in adult males. Possibly their most distinctive feature is their short, thick tail, which is often arched over their backs. Their genitals and hindquarters are a darker red. Babies are born a darker brown and become lighter as they age. Compared to the southern pig-tailed macaque, northern pig-tailed macaques have a grayer pelage and more pronounced cheek ruffs.

These macaques are both terrestrial and arboreal, spending time both in the trees and on the ground; the amount of time spent in either can depend on the habitat. They can travel approximately 1.2 miles a day throughout their home range, which tends to be around 0.17 square miles, although their ranging behavior changes with the season and fruit availability.

Northern pig-tailed macaques are not considered to be territorial; they don’t engage in conflicts with neighboring groups at the borders of their home ranges, and these home ranges overlap extensively between different groups. They pick a sleeping site each night; sites are sometimes reused but usually not two nights in a row.

Northern pig-tailed macaques live in multi-male, multi female groups. In general, there are many more females per group than males. Group size can vary, averaging around 23 individuals, but can contain as many as 50 individuals.

The group members are organized into hierarchies, which can dictate much of daily life. Males will usually leave the group at sexual maturity to find a new group to integrate into. Females usually stay in their birth group, forming close matrilines of mothers, daughters, sisters, and aunts. Higher-ranking individuals usually have priority access to resources like food and mates, and both females and males engage in mounting behaviors to signal dominance toward group mates.

Northern pig-tailed macaques play an important ecological role in their habitats. Their frugivorous diet means that they spread the seeds of dozens of plant species by swallowing, spitting, and dropping them throughout their range. For some plant species, the process of being digested by these macaques makes the seeds more likely to germinate after they return to the forest in the macaque’s feces, thereby highlighting the important role these monkeys play in regenerating forest habitat.

The northern pig-tailed macaque is listed under the Convention on International Trade in Endangered Species (CITES) Appendix II. It is also listed under various wildlife protection acts in Bangladesh, China, and India. While it occurs in several protected areas, more protections are needed for the species.

In particular, habitat preservation is required to prevent further population decreases. No current monitoring programs are in place and specific area conservation plans are required, as well as education and awareness programs.

Jennifer Botting, PhD, September 2020 (New England Primate Conservancy); Indian Mammals A Filed Guide (Vivek Menon); Flora and Fauna of Bangladesh- Vol-27- BAS.

Author is a wildlife photographer & writer in Bangladesh.