ROLOWAY MONKEY
Cercopithecus roloway
Geographic Distribution and Habitat
The arboreal roloway monkey, also called the roloway guenon, is found in the canopy of the deciduous riverine and lowland moist forests of West Africa, sprinkled in small areas between the Sassandra River in Ivory Coast and the Pra River in Ghana. Some populations prefer mangroves and swampy areas (like the Kwabre Swamp Peat Forest on the Ghana-Ivory Coast border), away from human activity, where groups can find food and water in abundance. Museum records indicate that the species may have lived in Togo, to the east of Lake Volta, in the past, but there is no evidence of its presence there today, as the species is unfortunately rapidly declining and is already nearing extinction, even in protected areas like the Bia National Park (Ghana).
The arboreal roloway monkey, also called the roloway guenon, is found in the canopy of the deciduous riverine and lowland moist forests of West Africa, sprinkled in small areas between the Sassandra River in Ivory Coast and the Pra River in Ghana. Some populations prefer mangroves and swampy areas (like the Kwabre Swamp Peat Forest on the Ghana-Ivory Coast border), away from human activity, where groups can find food and water in abundance. Museum records indicate that the species may have lived in Togo, to the east of Lake Volta, in the past, but there is no evidence of its presence there today, as the species is unfortunately rapidly declining and is already nearing extinction, even in protected areas like the Bia National Park (Ghana).
Roloway monkey geographic range. Map credit: rbrausse-IUCN/Creative Commons
Size, Weight, and Lifespan
This monkey is sexually dimorphic. Males average 20-24 in (52-61 cm) long and 8-15 lbs (4–7 kg), whereas females average 17 in (45cm) and 8 lbs (4 kg). Although there is no confirmation on the longevity of roloway monkeys in the wild, it is estimated they can live up to 20 years, whereas the oldest individual in captivity reached the ripe age of 31. Appearance
With a lean dark gray body, a patch of brown on the back, and red fur on the inner thighs, the roloway guenon is quite beautiful. The tail is longer than the body—27 in (700 mm) for females and 45 in (900 mm) for males—and the limbs are thin and muscular. The creamy beige fur that elegantly frames the face with a thin line on the forehead, sideburns, and a long pointy beard, extends to the chin, chest, and upper arms. The thin black face has elongated nostrils pointing downward. The hazelnut eyes are large with grayish eyelids. The mouth protrudes out and contains a set of powerful teeth with sharp canines and convenient cheek pouches to store food. The male’s canines are bigger than the female’s, and the skull is relatively flat. Like us, the hands have five fingers with fingernails. Both hands and feet have opposable thumbs. Babies are black with white fur on the chest, chin, and upper arms. There is only a thin white stripe on their forehead and the sideburns are not grown yet, so their big black ears are exposed. Their eyes appear much bigger than in adults and the beard is hardly noticeable. |
What Does It Mean?Diospyros:
A genus of more than 700 evergreen trees and shrubs that grow in tropical climates. Examples are ebony and persimmon trees. Epiphyte: A plant that grows on the surface of another plant or tree, but gets its nutrients from the air, rainfalls, and compost from the plant it rests on. Some examples are moss, lichen, liverwort, fern, and orchids. In tropical forests, epiphytes grow in the canopy. About 10% of all vascular plant species worldwide are epiphytes and most are found in tropical forests. Iroko tree: A large hardwood tree from the tropical forest of West Africa. It can live 500 years and is believed to have supernatural properties. It produces oji wood, also known as African teak, although not related to the teak family. It is now being burned or cut to leave space for cocoa plantations. Philopatric: Returning to one’s birthplace or remaining with one’s birth group. |
Photo credit: Tim Ellis/Flickr/Constant Commons
Diet
The diet of the roloway guenon is rich in fruit, insects, leaves, and seeds. It is estimated that they can feed on plant matter from 130 species, including various epiphytes, such as mosses, lichens, and orchids. In the Bia National Forest, insect feeding peaks in the wet season, whereas the consumption of fruit pulp and seeds peaks in the dry season. The roloway guenons like the petioles of leaves of Diospyros, evergreen trees. They also eat animal matter, consisting of animal feces and remains. Males eat more fruit than females; females eat more foliage and animal matter, as the nutritional value is more important, especially during pregnancy.
The diet of the roloway guenon is rich in fruit, insects, leaves, and seeds. It is estimated that they can feed on plant matter from 130 species, including various epiphytes, such as mosses, lichens, and orchids. In the Bia National Forest, insect feeding peaks in the wet season, whereas the consumption of fruit pulp and seeds peaks in the dry season. The roloway guenons like the petioles of leaves of Diospyros, evergreen trees. They also eat animal matter, consisting of animal feces and remains. Males eat more fruit than females; females eat more foliage and animal matter, as the nutritional value is more important, especially during pregnancy.
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Behavior and Lifestyle
The roloway monkey is diurnal. Troop size varies from 6 to 20 or even 30 individuals. Females are philopatric (i.e., remain in their native group), whereas males disperse usually once they have reached maturity. There is typically one dominant male and multiple females with their young. Daily Life and Group Dynamics
The group spends most of its time foraging and grooming, and stays up in the canopy. Males seem to be responsible for keeping the group together and ensure that no individual stays too far apart from the others. Communication
Like all other primates, roloway guenons use vocalizations (croaks, chuckles, loud calls), visual cues, olfactory signals, and body postures to communicate. The males use a “gathering” call to tell the members of the group to stick together. Grinning, pulling the lips to reveal canines, head bobbing, and yawns are used to threat or intimidate another individual. They use different predator calls. Some studies indicate that adult female guenons do occasionally produce male call variants during events that would normally warrant a male to respond, if the male fails to do so. Reproduction and Family
Females become mature at 4 or 5 years of age; males mature a couple of years later. Roloway monkey females give birth to one offspring after a gestation period of about 5 to 6 months. They breastfeed the babies for about 180 days. There is no literature confirming the breeding season or birth interval—it is thought they may breed year-round and environmental factors, such as weather and food abundance, probably influence reproduction cycles. Field observations seem to indicate that, like Diana monkeys, the breeding system is polygynous (i.e., one male mates with several females). |
Fun FactsJohann Christian Daniel von Schreber – a German naturalist (1739-1810) was the first to name the roloway guenon – Cercopithecus diana roloway – in the world mammals encyclopedia he published in 1779. Die Säugethiere in Abbildungen nach der Natur mit Beschreibungen. The Diana monkey and roloway guenon were considered subspecies until 2001, when late Professor Colin Groves elevated both to the status of distinct species in his “Primate Taxonomy” In Ghana, the roloway guenon is called “Efiai aighéhi” which translates as “the monkey with a white beard”. |
Threat display. Photo credit: Tim Ellis/Flickr/Constant Commons
Ecological Role
The roloway guenon contributes to seed dispersal, and thereby also to the health of tropical forests.
The roloway guenon contributes to seed dispersal, and thereby also to the health of tropical forests.
Conservation Status and Threats
The International Union for the Conservation of Nature lists the roloway monkey as Critically Endangered (IUCN, 2019). In addition, The roloway guenon is listed in the IUCN's report entitled Primates in Peril: the World’s 25 Most Endangered Primates, 2017.
This guenon thrives in the canopy of rich lush forests. It can survive in lightly logged forests, where the canopy is untouched, but it is not able to adapt to any other environment and is a victim of destruction of mature rainforest caused by logging, conversion of land to agriculture (cocoa, rubber, palm oil), and charcoal production.
Additionally, because it is a rather large monkey and its meat and fur are sought after, it is the perfect target of hunters, despite laws prohibiting the hunting of wildlife.
Recent estimates on the total roloway guenon population are not available, but surveys reporting sightings of the species are less and less frequent. Its presence was confirmed in the late 1990s in the Parc National des Iles Ehotilé and in the Yaya Forest; unfortunately in 2006 its presence in either place could not be confirmed. By now, it is entirely possible that the species is extinct at both sites. If such is the case, the roloway guenon may only still exist in the Tanoé Forest.
Predators in the wild include crowned hawk-eagles, leopards, chimpanzees, and humans.
The International Union for the Conservation of Nature lists the roloway monkey as Critically Endangered (IUCN, 2019). In addition, The roloway guenon is listed in the IUCN's report entitled Primates in Peril: the World’s 25 Most Endangered Primates, 2017.
This guenon thrives in the canopy of rich lush forests. It can survive in lightly logged forests, where the canopy is untouched, but it is not able to adapt to any other environment and is a victim of destruction of mature rainforest caused by logging, conversion of land to agriculture (cocoa, rubber, palm oil), and charcoal production.
Additionally, because it is a rather large monkey and its meat and fur are sought after, it is the perfect target of hunters, despite laws prohibiting the hunting of wildlife.
Recent estimates on the total roloway guenon population are not available, but surveys reporting sightings of the species are less and less frequent. Its presence was confirmed in the late 1990s in the Parc National des Iles Ehotilé and in the Yaya Forest; unfortunately in 2006 its presence in either place could not be confirmed. By now, it is entirely possible that the species is extinct at both sites. If such is the case, the roloway guenon may only still exist in the Tanoé Forest.
Predators in the wild include crowned hawk-eagles, leopards, chimpanzees, and humans.
Conservation Efforts
The roloway monkey is listed in Appendix I of Convention on International Trade in Endangered Species (CITES), as well as in Class A of the African Convention on the Conservation of Nature and Natural Resources, and is therefore protected.
The forests in Ghana are now only 20% of their original size, and, since its independence in the 1960s, Ivory Coast has lost over 65% of its original forests. Deforestation and habitat degradation are due to the growing demand for tropical hardwood and the rapid expansion of commercial and subsistence farming. The legendary Iroko tree, for instance, is cut to make space for cocoa plantations that produce 40% of the world's cocoa. Although areas of forest are protected both in Ivory Coast and Ghana, illegal plantations flourish and “dirty” cocoa infiltrates the lucrative market. Recent studies outline that deforestation in protected areas is happening twice as fast as in unprotected areas.
Some governmental and international organizations fiercely combat to reverse this trend. For instance, the Rainforest Trust, partnering with the Swiss Center for Scientific Research (CSRS), has been working to create a community forest reserve to protect the swampy Tanoé Forest (29,653 acres) at the border of Ghana, now a high-priority site for primate conservation and one of the last strongholds of the roloway guenon. Residents of eight surrounding villages manage the forest and are all actively engaged in opposing large-scale oil palm plantations. The goal is to engage Ghana’s neighboring communities to form a forest patrol and further expand the Tanoé Forest conservation efforts.
West African Primate Conservation Action (WAPCA) is an organization dedicated to the protection of mangabey and roloway monkeys. The organization focuses on education to promote forest conservation. They train local citizens to use a GPS to track the presence of monkeys and learn about the species. They teach the importance of keeping wild animals alive, organize field trips in the forest with high school students, and sponsor cultural events, such as plays, to ensure the next generations and future leaders understand the importance of conservation to secure a future not only for primates but for humans as well. They also work closely with researchers at the University of Cocody in Ivory Coast.
The roloway monkey is listed in Appendix I of Convention on International Trade in Endangered Species (CITES), as well as in Class A of the African Convention on the Conservation of Nature and Natural Resources, and is therefore protected.
The forests in Ghana are now only 20% of their original size, and, since its independence in the 1960s, Ivory Coast has lost over 65% of its original forests. Deforestation and habitat degradation are due to the growing demand for tropical hardwood and the rapid expansion of commercial and subsistence farming. The legendary Iroko tree, for instance, is cut to make space for cocoa plantations that produce 40% of the world's cocoa. Although areas of forest are protected both in Ivory Coast and Ghana, illegal plantations flourish and “dirty” cocoa infiltrates the lucrative market. Recent studies outline that deforestation in protected areas is happening twice as fast as in unprotected areas.
Some governmental and international organizations fiercely combat to reverse this trend. For instance, the Rainforest Trust, partnering with the Swiss Center for Scientific Research (CSRS), has been working to create a community forest reserve to protect the swampy Tanoé Forest (29,653 acres) at the border of Ghana, now a high-priority site for primate conservation and one of the last strongholds of the roloway guenon. Residents of eight surrounding villages manage the forest and are all actively engaged in opposing large-scale oil palm plantations. The goal is to engage Ghana’s neighboring communities to form a forest patrol and further expand the Tanoé Forest conservation efforts.
West African Primate Conservation Action (WAPCA) is an organization dedicated to the protection of mangabey and roloway monkeys. The organization focuses on education to promote forest conservation. They train local citizens to use a GPS to track the presence of monkeys and learn about the species. They teach the importance of keeping wild animals alive, organize field trips in the forest with high school students, and sponsor cultural events, such as plays, to ensure the next generations and future leaders understand the importance of conservation to secure a future not only for primates but for humans as well. They also work closely with researchers at the University of Cocody in Ivory Coast.
Photo courtesy of ARKive.org
References:
- "First Sightings of the Roloway Monkey (Cercopithecus diana roloway) in Ghana in Ten Years and the Status of Other Endangered Primates in Southwestern Ghana" - David Osei1, Robert H. Horwich2, and Jeanne Marie Pittman1 (1 West African Primate Conservation Action, Accra Ghana /2 Community Conservation, Gay Mills, WI USA)
- Monkeyland Sanctuary – South Africa - website
- Rain Forest Trust organization website.
- Canopy Watch International blog.
- "Wildlife in jeopardy inside and outside protected areas in Côte d’Ivoire: the combined effects of disorganization, lack of awareness and institutional weakness" – Inza Koné
- "Roloway Guenon – Ghana and Côte d’Ivoire" – W. Scott McGraw and John F. Oates
- The Guardian – “Chocolate Industry drives rainforest destruction in Ivory Coast”
- “Chocolate’s Dark Secret” report from the Mighty Earth organization.
- "Primates in Peril: The World’s 25 Most Endangered Primates 2006-2008" – Mittermeier, Ratsimbazafy, Rylands, Williamson, Oates, Mbora, Ganzhorn, Rodríguez-Luna, Palacios, Heymann, Kierulff, Yongcheng, Supriatna, Roos, Walker and Aguilar.
- Animalia bio website
- "African Primates – Surveys from the Subri River Forest Reserve, Ghana" – Buzzard and Parker
- Encyclopedia of Life website
- "Language and Recursion" – Lowenthal and Lefebvre
Written by Sylvie Abrams, February 2018
