Animal Diversity Web

Geographic Range

Roloway monkeys are found living in groups in Western Africa, ranging from the Pra River in Ghana to east of the Sassandra River in the Ivory Coast. They have also been reported as far east as Kakum in Ghana. (Curtin, 2013; Oates, 1988)

• Biogeographic Regions
• ethiopian
  • native

Habitat

Roloway monkeys are arboreal primates found in mature forests. They inhabit first-and second-growth deciduous forests and lowland moist forests. In captivity, Roloway monkeys prefer an environment that provides elevated habitat. In the wild, they also prefer to navigate tree top habitats. Some populations show a preference for mangroves such as Pandanus candelabrum and Cyrtosperma senegalense. Mangroves are located away from the pressures of human populations and allow the monkeys to gather in larger groups because mangroves offer a constant supply of food, water, and protection. (Bi, et al., 2013; Curtin, 2002; Kingdon, 1997; Oates, 1988; Wiafe, 2013)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest

Physical Description

Roloway monkeys are one of the largest guenons, very similar in appearance to Diana monkeys. Both have a dark grey body with a crimson patch on their lower back, red on their inner thigh, and a light stripe down the exterior part of their thigh. Beige to light orange fur runs down their chest, extending midway down the arms and up the ears and chin. Roloway monkeys have a more pronounced beige strip across their forehead and a longer beard. The crimson patch extends higher up the back, they lack ear tufts, and their inner thigh is lighter in color. Their tails are longer than their body and they are in the group of monkeys that possess cheek pouches to store food. Roloway monkey skulls are relatively flat and without an elongated rostrum. They have nostrils that are only slightly separated and pointing downward. They have nails on all digits and possess opposable thumbs. Roloway monkeys are sexually dimorphic; males have a larger body size and larger canines than females. The dental formula: I 2/2 C 1/1 P 2/2 M 3/3 =32. Roloway monkeys have 2n=58 chromosomes.

There are few body measurements of adult Roloway monkeys; available measurements are from unknown sexes or unknown life stages. Diana monkeys have body lengths of 440 to 450 mm in adult females and 525 to 615 mm in adult males. They have a tail length of 700 to 725 mm in adult females and 800 to 901 mm in adult males. (Chu and Giles, 1957; Napier and Napier, 1967; Napier, 1981; Sanderson, 1957; Young, 1998)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• ornamentation

Reproduction

Little is known about the mating system of Roloway monkeys. The closely related species, Diana monkeys have a polygynous mating system. Their groups consist of one male with many females and their offspring. Roloway groups have a similar group structure, consisting of one dominant adult male and multiple adult females with their offspring. This may suggest that Roloway monkeys have a polygynous mating system similar to Diana monkeys. (Curtin, 2002; Vaughan, 1986; Young, 1998; Zuberbuhler, 2002)

Little is known about reproduction of this species in the wild. Species in the genus Cercopithecus don't have a specific breeding season and breeding may be influenced by environmental factors. Guenon species have a regular estrus cycle lasting, on average, 30 days. Single births are most common and twins are rare. (Napier and Napier, 1967)

• Key Reproductive Features
• iteroparous
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding interval

  Breeding intervals in Roloway monkeys are not reported in the literature.

• Breeding season

  Breeding season in Roloway monkeys is not reported in the literature. They may breed year-round.

• Range number of offspring

  1 to 2

• Average number of offspring

  1

Diana monkey offspring are born with their eyes open. Their deciduous incisors grow in early and the milk teeth are present at 20 months. Adult teeth begin to grow at just over 2 years of age. It may take over a year for all adult teeth to come in and adult canines come in as the individual reaches sexual maturity. Mothers care for their offspring. Female offspring stay with the group while male offspring disperse. (Hill, 1953; Macdonald, 1984)

• Parental Investment
• female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifespan/Longevity

There have been no long term studies conducted on wild populations of Roloway monkeys. The oldest animal in captivity lived for 31 years. (Napier and Napier, 1967)

• Average lifespan
  Status: captivity

  31 years

Behavior

Roloway monkeys are diurnal and arboreal quadrupeds. When traveling through the forest, they take the most direct route, rather than jump from branch to branch. Groups range from 6 to 22 individuals, consisting of one dominant male and multiple females and their young. They use vocalization and body posture to communicate. Roloway monkeys spend a considerable amount of time grooming. At a young age, Roloway monkeys are gentle and unassertive. As they become older and stronger, they become more assertive. In captivity, Roloway monkeys behave in ways similar to wild populations when their enclosures provide tree-like habitat that mimics canopy. Roloway monkeys have been observed at densities of 1.53 groups per square kilometer in forests of Ghana and 0.38 groups per square kilometer in forests of Ivory Coast. (Hill, 1953; Sanderson, 1957; Vaughan, 1986; Wiafe, 2013; Zuberbuhler, 2002)

• Key Behaviors
• arboreal
• scansorial
• diurnal
• motile
• sedentary
• social

Home Range

Home range sizes are not reported for Roloway monkeys. (Bi, et al., 2013; Magnuson, 2002)

Communication and Perception

All guenon species generate croaks and chuckles. Roloway monkeys also produce loud, long yells. They produce warning calls in response to disturbances. (Magnuson, 2002; Sanderson, 1957)

• Communication Channels
• visual
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Roloway monkeys obtain food from various epiphytic species and large trees. They feed primarily on insects, but also eat seeds and pulp of mature fruits and leaves. Insect foraging can last over an hour in a group. In the Bia National forest, feeding on insects and leaves starts at the end of the dry season and peaks in the wet season. Meanwhile, feeding on mature fruit pulp and seeds peaks in the dry season, where fruits provide both nutrients and moisture.

• Primary Diet
• omnivore

• Animal Foods
• insects

• Plant Foods
• leaves
• seeds, grains, and nuts
• fruit
• flowers

Predation

Non-human predation on Roloway monkeys is mainly from leopards and large birds of prey. Roloway monkeys have a non-cryptic color pattern; they rely heavily on warning calls and predator recognition to avoid predation. Human predators have the largest influence on these primates; they pressure the population through habitat loss from logging and farming, as well as hunting with shotguns and wire snares. (Napier and Napier, 1967; Oates, 1988; Sanderson, 1957; Wiafe, 2013)

• Known Predators

  • leopards (Panthera pardus)

Ecosystem Roles

Not a lot is known about the impact of Roloway monkeys on the ecosystems they inhabit. They may impact seed dispersal through their predation on fruits. (Curtin, 2002)

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Humans hunt Roloway monkeys for fur and bush meat. (Bi, et al., 2013; Lindsay, 1996)

• Positive Impacts
• food

Economic Importance for Humans: Negative

Roloway monkeys have no known negative effect on humans. There is no evidence of them being disease or pathogen vectors. Roloway monkeys are not known to cause crop damage and they are not aggressive. (Curtin, 2013; Wolfheim, 1983)

Conservation Status

Roloway monkey populations appear to have experienced a large decline in the past few decades and are considered one of the most endangered monkey species in the world. Populations are under pressure due to habitat degradation caused by logging and crop production, as well as illegal poaching. It is estimated that the population in Ghana has dropped below 1,000. Many reserves and parks have supported populations of Roloway monkeys in the past, but those populations have been eradicated recently. There have been a few community projects aimed at education and conservation and an Endangered Species Program in Europe has been established for this species. Nonetheless, Roloway monkeys have been moved from critically endangered in 2000 to endangered in 2008 on the IUCN Red list. (Hilton-Taylor, 2000; Jones, 1962; Konstant, et al., 2002; Lindsay, 1996; Magnuson, 2002; Oates, et al., 2008; Wiafe, 2013; Young, 1998)

• IUCN Red List

  Endangered

• CITES

  Appendix I

Other Comments

Roloway monkeys are sometimes considered a subspecies of Diana monkeys in the literature, referred to as Cercopithecus diana roloway. In recent studies, Roloway monkeys have been considered a distinct species. There is no published research comparing the genetics of Roloway and Diana monkeys. Few studies have been conducted on Roloway monkeys in the wild. (Curtin, 2002; Groves, 2005; Hill, 1953; Napier, 1981)

Contributors

Kelsey Johnson (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

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Chu, E., N. Giles. 1957. A Study of Primate Chromosome Complements. American Naturalist, 91/860: 273-282.

Curtin, S. 2013. Cercopithecus roloway Roloway Monkey. Pp. 313-314 in T Butynski, J Kingdon, J Kalina, eds. Mammals of Africa, Vol. 2. London, New York: Bloomsbury Publishing.

Curtin, S. 2002. Diet of the roloway monkey, Cercopithecus diana roloway, in Bia National Park, Ghana. Pp. 351-371 in M Glenn, M Cords, eds. The Guenons Diversity and Adaptations in African Monkeys. New York, Boston, Dordrecht, London, Moscow: Kluwer Academic/ Plenum Publishers.

Groves, C. 2005. Order Primates. Pp. 111-184 in D Wilson, D Reeder, eds. Mammal Species of the World, Vol. 1. Baltimore: The John Hopkins University Press.

Hill, W. 1953. Primates:comparative anatomy and taxomony. Edinburgh: University Press.

Hilton-Taylor, C. 2000. The 2000 IUCN Red List of Threatened Species. Gland, Switzerland: IUCN.

Jeserich, P. 2004. Vergleichende Verhaltensstudie einer Gruppe Roloway-Meerkatzen (Cercopithecus diana roloway) im Tiergarten Heidelberg in zwei unterschiedlichen Gehegen. Zoologische Garten, 74/6: 328-348.

Jones, M. 1962. Mammals in captivity-primate longevity. Laboratory Primate Newsletter, 1/3: 3-13.

Kingdon, J. 1997. The Kingdon field guide to African mammals. San Diego: Academic Press.

Konstant, W., B. Mittermeier, A. Rylands, T. Butynski, A. Eudey, J. Ganzhorn, R. Kormos. 2002. The world's 25 most endangered primates 2002. Neotropical Primates, 10: 128-131.

Lindsay, N. 1996. Roloway Monkey Project, Ghana. International Zoo News, 43/5: 300-301.

Macdonald, D. 1984. Encyclopedia of Mammals. New York: Facts on File Publications.

Magnuson, L. 2002. Distribution and abundance of the roloway monkey Cercopithecus diana roloway and other Pimate species in Ghana. African Primates, 6/1-2: 19-26.

Napier, J., P. Napier. 1967. A Handbook of Living Primates. New York, New York: Academic Press Inc.

Napier, P. 1981. Catalogue of Primates in the British Museum (Natural History), Part 1:Family Callitrichidae and Cebidae. London: British Museum (Natural History).

Oates, J. 1988. The distribution of Cercopithecus monkeys in West African forests. Pp. 79-103 in A Gautier-Hion, F Bourliere, J Gautier, J Kingdon, eds. A primate radiation:Evolutionary biology of the African guenons. Cambridge: Cambridge University Press.

Oates, J., S. Gippoliti, C. Groves. 2008. "The IUCN Red List of Threatened Species" (On-line). Accessed October 25, 2014 at http://www.iucnredlist.org/details/4232/0.

Sanderson, I. 1957. The Monkey Kingdom. Graden City, New York: Doubleday & Company, Inc.

Vaughan, T. 1986. Mammalogy. Orlando: Harcourt Brace Jovanovich.

Wiafe, E. 2013. Status of the Critically Endangered Roloway Monkey (Cercopithecus diana roloway)in Dadieso Forest Reserve, Ghana. African Primates, 8: 9-16.

Wolfheim, J. 1983. Primates of the World: Distribution, Abundance and Conservation. Seattle: University of Washington Press.

Young, R. 1998. Behavioural studies of guenons Cercopithecus spa. at Edinburgh Zoo. International Zoo Yearbook, 36/1: 49-56.

Zuberbuhler, K. 2002. Effects of natural and sexual selection on the evolution of guenon loud calls. Pp. 289-306 in M Glenn, M Cords, eds. The Guenons Diversity and Adaptations in African Monkeys. New York, Boston, Dordrecht, London, Moscow: Kluwer Academic/ Plenum Publishers.