Lesser Spot-Nosed Guenon, Cercopithecus petaurista
LESSER SPOT-NOSED GUENON
Geographic Distribution and Habitat
The lesser spot-nosed guenon, also known as the spot-nosed monkey, the lesser white-nosed guenon, and the lesser white-nosed monkey, is a very adaptable monkey found on the west coast of Africa, from swampy areas and thickets to fringe forests and coastal scrublands. They generally live in the lower layer of the forest canopy. They can be spotted in Ghana, the Ivory Coast, Guinea, Liberia, Sierra Leone, and Togo. There have also been possible sightings in Senegal.
Size, Weight, and Lifespan
Male lesser spot-nosed guenons are 3.8 feet (1.2 m) in length and can weigh up to 13 pounds (6 kg) while females are 3.3 feet (1 m) in length and can weigh up to 9 pounds (4 kg).
The lesser spot-nosed guenon has an average lifespan of 17-19 years.
If ever there was a monkey that looked like it leaped from the pages of a Dr. Seuss book, the lesser spot-nosed guenon would be it. A distinguished mustache, beard, and throat ruff are complemented by blue-tinged skin and a fuzzy, white, heart-shaped nose that seems to be painted on by accident.
Lesser spot-nosed guenons are small and lithe quadrupedal monkeys. They have tiny, protruding ears and a thick yellow-brown pelage flecked with black and yellow. Their non-prehensile tails are about two feet (61 cm) long and used for balance.
There isn’t a lot on the menu when it comes to lesser spot-nosed guenons. They eat a diet that consists mostly of fruit, leaves, and some insects. They gather food and store it in their cheek pouches to eat later unhurried and safely away from threats of predators, competitors, or thieves.
Behavior and Lifestyle
The lesser spot-nosed guenon is diurnal (active in daytime), arboreal (tree-dwelling), and enigmatic (mysterious). This little monkey is very cautious, so it skitters and meanders through the forest understory in order to avoid predators like leopards on the ground; it also steers clear of the high canopy where birds of prey could be circling.
Unfortunately, very few studies have been conducted on this species.
Lesser spot-nosed guenons live in social groups of 20-30 individuals, mostly consisting of females and one male. Only the females are permanent residents—the males leave at puberty to either live solitary lives or join another group.
Guenon groups can sometimes be comprised of other monkey species as well, which is pretty beneficial to all. Ever hear the phrase “safety in numbers”? Well, it applies here because each guenon species understands the others’ calls and therefore they know how to react during an alarm call.
Different guenon species often mix together, but that does not mean they interbreed. The variety of guenon facial features allows them to distinguish between species and identify individuals.
The lesser spot-nosed guenon uses a couple of different communication techniques. The male of the group will emit an alarm call reminiscent of a cat purr that distracts any potential predators so the rest of the troop can seek shelter elsewhere. Guenons will also display and interpret body language—they open their mouths to show their teeth, close their eyelids, and move their head or tail to get a message across to others.
The gestational period for the lesser spot-nosed guenon is approximately 165-170 days and the birth weight is around 8 oz (230 g). Guenon mothers are the main caregivers, although other females may assist. Guenon infants are carried by the mother until they are able to climb on their own at two weeks of age. Infants attain their adult coloration at two to three months. Surprisingly, they are not born with a white nose! At nine to eighteen months, infants are weaned.
The lesser spot-nosed guenon plays an important role in seed dispersal because of its consumption of leaves and fruit. It also fills an ecological niche in the food chain by acting as both predator (to invertebrates like insects) and prey to animals like birds of prey, leopards, and chimpanzees.
The International Union for Conservation of Nature has assessed the lesser spot-nosed guenon as Near Threatened (IUCN, 2017). The species is facing serious threats from habitat loss and hunting. Although a generally resilient species that adapts to a wide variety of degraded habitats, uncontrolled hunting is taking its toll. It is the primary threat to the lesser spot-nosed monkey. Due to its small body size, lesser spot-nosed guenons were not major targets of hunting until recently. However, because the populations of larger-bodied primates, such as the colobines and mangabeys, have been greatly reduced or even extirpated from many forests by uncontrolled hunting, even this small-bodied monkey is now a target for hunters. Hunting is increasingly targeting smaller-bodied primates such as lesser spot-nosed monkeys throughout it range countries.
Like most other primates, they are also beginning to suffer the effects of habitat loss as humans expand further and further into their territory. Habitat loss, habitat degradation, and habitat fragmentation are other threat factors. In Ghana and Côte d’Ivoire, large-scale and small-scale conversion of forests into cash-crop plantations have reduced the forest cover by about 15% of the former extent in the last twenty years. Mining for gold, diamonds, bauxite, and other minerals also threatens the species’ survival.
As logging roads start to expand into the forests, guenons find themselves more and more the target of the illegal bushmeat trade. Guenon mothers have been killed and their babies kept as pets.
Unless conservation efforts within its range improve significantly the lesser spot-nose monkey is likely to qualify for a Vulnerable threat status before long, and in some parts of its range it is already Endangered. In Togo, in particular, it probably qualifies already for Vulnerable status and may be nationally Endangered.
There are many organizations designed to support guenon populations. The Association of Zoos and Aquariums (AZA) is involved in the conservations efforts through their Species Survival Plans to maintain genetic diversity. The San Diego Zoo Global Wildlife Conservancy is also striving to protect species like the lesser spot-nosed guenon around the world.
Written by Rachel Heim, November 2018. Conservation status updated July 2020.