Spot-nosed Monkey

The Spot-nosed Monkey is a small, agile guenon native to the lowland rainforests of West Africa, easily recognized by the distinctive white or yellow spot on the tip of its nose. It is highly arboreal and often found in mixed-species groups foraging in the forest canopy. This species is remarkable for its acrobatic locomotion, including impressive leaping abilities that give rise to its species name 'petaurista' (meaning acrobat or leaper).

West Africa, primarily coastal countries from Senegal/Guinea-Bissau to Benin, including Sierra Leone, Liberia, Côte d'Ivoire, Ghana, Togo, and Benin.

Distributed across the Upper Guinea forest zone of West Africa, spanning from Senegal and Guinea-Bissau through Sierra Leone, Liberia, Côte d'Ivoire, Ghana, Togo, to Benin.

Altitude and depth

Typically found at low to moderate altitudes, generally below 1000m, with most populations in lowland forests near sea level.

Seasonal movements

No true hibernation or migration; however, foraging patterns and range use may shift seasonally in response to fruit availability during wet and dry seasons.

Primary and secondary lowland tropical rainforest, gallery forests, and forest edges; also found in swamp forests and disturbed/degraded forest patches near human settlements.

Adaptations to its environment

Long limbs and a long tail provide excellent balance and agility for rapid arboreal locomotion and leaping between forest canopy branches. Cryptic coloration and quick reflexes help avoid predation, while a flexible omnivorous diet allows adaptation to varying food availability.

Near Threatened (NT) according to IUCN, primarily due to ongoing habitat loss and fragmentation from deforestation and hunting pressure across its range, though it remains relatively adaptable compared to some forest primates.

Estimated population

No precise global population estimate exists, but the population is considered to be declining due to continued habitat loss and hunting pressure across its range.

Deforestation and habitat fragmentation from logging and agricultural expansion, bushmeat hunting, and habitat degradation due to human population growth in West Africa.

Diseases and parasites

Susceptible to various gastrointestinal parasites and can carry simian immunodeficiency virus (SIV) strains; also affected by external parasites such as ticks and mites common to forest primates.

Protected in several national parks and reserves within its range, including Taï National Park (Côte d'Ivoire) and Kakum National Park (Ghana); listed on CITES Appendix II regulating international trade.

Recommended actions

Strengthen enforcement of hunting bans in protected areas, expand forest corridor connectivity between fragmented habitats, and conduct further population monitoring to better assess trends.

The fur is generally dark olive to blackish on the back with a lighter grayish underside, and the face is dark with a distinctive small white or yellowish spot on the tip of the nose. The tail is long and often held in a curved or looped position.

Size

Body length (head-body) typically 34-57 cm, with a tail length of 55-90 cm, making the tail notably longer than the body.

Weight

Adult males typically weigh 3.5-4.5 kg, while females are smaller, weighing around 2.5-3.5 kg.

Distinctive features

The prominent white/yellow nose spot is the key identifying feature distinguishing it from closely related guenon species; it also has relatively large eyes and a slender build suited to fast arboreal movement.

Differences between males and females

Males are noticeably larger than females, with males weighing up to 30-40% more; males also have more prominent canine teeth.

Lives in social groups typically consisting of one adult male and multiple females with offspring, averaging 15-30 individuals; frequently forms polyspecific associations with other guenon species like Diana monkeys for predator protection.

When it is active

Diurnal, with activity concentrated in the early morning and late afternoon; rests during the hottest midday hours in dense canopy cover.

Diet

Omnivorous diet consisting mainly of fruits, seeds, young leaves, flowers, and insects; opportunistically consumes small invertebrates and occasionally bird eggs.

How it feeds and hunts

Forages actively through the canopy, using dexterous hands to manipulate fruits and search foliage for insects; relies on visual and tactile searching rather than active predation techniques.

Communication

Uses a range of vocalizations including alarm calls, contact calls, and loud male territorial calls; also communicates through facial expressions, body postures, and scent marking.

Interactions with other species

Natural predators include crowned eagles, leopards, and chimpanzees; often forms protective polyspecific groups with Diana monkeys and other guenons to enhance predator detection and defense.

Role in its ecosystem

Plays an important ecological role as a seed disperser for various fruiting tree species in West African rainforests, contributing to forest regeneration and plant diversity.

Breeding is generally non-seasonal, though births may peak during periods of higher food availability; gestation lasts approximately 5-6 months, typically resulting in a single offspring.

Raising the young

Females provide primary care, including nursing and carrying infants for several months; weaning generally occurs by 6-12 months, though juveniles remain close to mothers for social learning.

Maturity and lifespan

Sexual maturity is typically reached around 4-5 years of age; lifespan in the wild is estimated at 20-25 years, while captive individuals can live slightly longer with proper care.

Classification

Class Mammalia > Order Primates > Family Cercopithecidae > Genus Cercopithecus > Species Cercopithecus petaurista

Subspecies

Two recognized subspecies: Cercopithecus petaurista petaurista (found from Senegal to Ghana) and Cercopithecus petaurista buettikoferi (found in Liberia and western Côte d'Ivoire).

Scientific synonyms

Simia petaurista (original Linnaean name), Cercopithecus buettikoferi (formerly considered distinct species).

Recent studies

Recent genetic and behavioral studies have focused on polyspecific association dynamics with other guenons and the impact of forest fragmentation on gene flow between isolated populations.

Genome and DNA

Diploid chromosome number is 2n=72, typical for many Cercopithecus species; genetic studies have helped clarify subspecies boundaries and relationships with closely related guenons.

Compared with similar species

Similar to other spot-nosed guenons like Cercopithecus nictitans, but distinguished by smaller size, different nose spot coloration, and geographic range restricted to Upper Guinea forests rather than Central Africa.

The species name 'petaurista' means 'acrobat' in reference to its impressive leaping ability through the forest canopy. It often forms mixed-species troops with other monkeys, sometimes numbering over 100 individuals combined, to reduce predation risk.

Where and how to see it

Best observed in protected forest reserves such as Kakum National Park in Ghana or Taï National Park in Côte d'Ivoire, particularly during early morning hours when groups are actively foraging in the canopy.

Risks to humans

No notable risk to humans; the species is shy and avoids direct human contact, though it may raid crops near forest edges.

Human uses

Hunted locally for bushmeat in parts of its range; occasionally kept informally as pets, though this is not widespread or commercially significant.

Myths and legends

In some West African cultures, monkeys including guenon species feature in folklore as clever tricksters, though no widespread specific myths are documented uniquely for this species.