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)
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)
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)
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)
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)
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)
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)
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.
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)
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)
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)
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)
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)
Kelsey Johnson (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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