The bonnet macaque, Macaca radiata, is a species of Old World monkey found exclusively in southern India. This primate is easily recognized by the unique cap-like whorl of hair on its head, which gives the species its common name and helps differentiate it from other macaque species. This adaptable primate thrives in various environments across its native range.
Physical Characteristics and Habitat
Bonnet macaques possess a grey-brown or golden-brown fur coat, complemented by a long tail that aids in balance and communication. Their faces are hairless and wrinkled, often appearing pink in females. These medium-sized monkeys measure approximately 35 to 60 centimeters in head-body length and weigh between 3 to 6 kilograms. Males are generally larger, weighing up to 11.6 kilograms, while females are smaller, weighing up to 5.5 kilograms.
The species is endemic to peninsular India. Two subspecies exist, differing in belly coloration and geographical pockets within their range. Bonnet macaques inhabit a diverse array of environments, including evergreen and dry deciduous forests, grasslands, and human-altered landscapes such as agricultural fields, temples, and urban centers. They are also strong swimmers.
Social Structure and Behavior
Bonnet macaques are diurnal, spending their time both in trees and on the ground. They live in multi-male, multi-female social groups, often comprising around 30 individuals. Females remain within their birth groups, forming kin-bonded subgroups, while males disperse to join other troops.
The dominance hierarchy within bonnet macaque troops is linear. Older individuals hold more dominant positions within the group. Communication among bonnet macaques involves a range of vocalizations, body postures, and facial expressions.
Daily activities include foraging for their omnivorous diet, which consists of fruits, nuts, seeds, flowers, leaves, insects, eggs, and small reptiles. They also consume human-provided food and scavenge from trash in urban settings. Social grooming promotes group cohesion and reinforces social relationships.
Human Interaction and Conservation Status
Bonnet macaques frequently interact with humans, particularly in populated areas like temples, villages, and roadsides, where they are often fed. This close proximity can lead to human-wildlife conflict, as macaques may raid crops or be perceived as a nuisance. Such interactions have resulted in injuries to macaques, unplanned translocations, and even killings.
The International Union for Conservation of Nature (IUCN) classifies the bonnet macaque as Vulnerable, a change from its previous “Least Concern” status. This reclassification reflects significant population declines, exceeding 30% over three generations. A primary threat is habitat loss due to expanding human infrastructure, urbanization, and roadside development.
Another significant threat is competitive displacement by the rhesus macaque, Macaca mulatta, an increasingly aggressive and larger species expanding its range into bonnet macaque territory. This encroachment leads to competition for resources and a shrinking of available habitat. Other threats include hunting, trapping, and capture for the pet trade or research purposes.