Cercocebus agilisagile mangabey

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Geographic Range

Agile mangabeys, Cercocebus agilis, are found only in forested regions of central Africa that lie north of the Congo river. Currently, this species is found in southeastern Cameroon, eastern portions of continental Equatorial Guinea, northeastern Gabon, northern parts of the Republic of the Congo, southern and central parts of the Central African Republic, and northern parts of the Democratic Republic of the Congo. ("Agile Mangabey", 2007; Hart, et al., 2009; McGraw and Fleagle, 2006)

Habitat

Agile mangabeys live primarily in periodically flooded primary forests near bodies of fresh water. However, some populations in southern portions of the Central African Republic reportedly live in non-flooded mixed forests away from bodies of water. Agile mangabeys favor the understory and are generally terrestrial while feeding or traveling. ("Agile Mangabey", 2007; Hart, et al., 2009; McGraw and Fleagle, 2006)

Physical Description

Except for the tail region, the pelage of agile mangabeys is brownish-gray agouti that becomes darker on the back; the tail is agouti only at the base of the fur. The tips of the fur are generally black on the dorsal side of the body. The entire underside is a lighter fawn color. Hair on the head radiates out from a whorl just above the forehead. The bare skin of the hands and feet is black. Except for the upper eyelids, the skin of the ears and face is also black with a border of lighter skin at the hair line. The facial skin of infants begins light but darkens as they age. Color morphs of both light and dark variety reportedly co-occur with the typical color pattern. The size of this species varies somewhat, with western populations being slightly larger than eastern ones. All individuals have relatively long non-prehensile tails. Sexual dimorphism is significant, with adult females attaining only 60 percent of the mass of adult males. ("Agile Mangabey", 2007; Groves, 1978; Kingdon, 1997; McGraw and Fleagle, 2006)

The skull of agile mangabeys, like those of other members of genus Cercocebus, is exceptionally broad. Unlike other members of the subfamily Cercopithecinae, the upper molars of Cercocebus species are wider than they are long. The genus also possesses a "molar flare," which is shared with the rest of Cercopithecinae (other than guenons), as well as a long auditory meatus, wide interorbital pillar, and convex nasal bone. However, agile mangabeys have shorter and narrower skulls and smaller teeth than other Cercocebus species. ("Agile Mangabey", 2007; Groves, 1978; Kingdon, 1997; McGraw and Fleagle, 2006)

  • Sexual Dimorphism
  • male larger
  • Range mass
    5 to 13 kg
    11.01 to 28.63 lb
  • Range length
    44 to 65 cm
    17.32 to 25.59 in

Reproduction

Agile mangabeys live in small to medium-sized groups of animals that may include either one or several males. Females develop sexual swellings when they are in estrous. It is assumed that they are either polygynous or promiscuous, but not much is known about their mating behavior in the wild. (Burton and Burton, 2002; "Agile Mangabey", 2007; Burton and Burton, 2002; Flannery, 2007; Kingdon, 1997; Richardson, 2009)

Agile mangabeys begin breeding at age 4 to 5 and breed throughout the year with a gestation period of 165 to 175 days. They have only one offspring at a time. Newborn offspring are mostly hairless and cling to the underbelly fur of their mothers while the mothers move around. ("Agile Mangabey", 2007; Burton and Burton, 2002)

  • Breeding interval
    The breeding interval for agile mangabeys is not known.
  • Breeding season
    Agile mangabeys breed year round.
  • Average number of offspring
    1
  • Range gestation period
    165 to 175 days
  • Range age at sexual or reproductive maturity (female)
    4 to 5 years
  • Range age at sexual or reproductive maturity (male)
    4 to 5 years

Parental care is provided primarily by the mother in the form of nursing and carrying infants. However, males sometimes hold and carry infants. It is not known whether or not this behavior correlates with paternity. Upon reaching independence, the young group with others of the same age and generally avoid adults. (Burton and Burton, 2002; Kingdon, 1997)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • male
      • female
  • extended period of juvenile learning

Lifespan/Longevity

Agile mangabeys live for as long as 20 years in the wild, but average lifespan is unknown. Few agile mangabeys are kept in captivity, so their lifespan in captivity is also unknown. (Burton and Burton, 2002)

  • Range lifespan
    Status: wild
    20 (high) years

Behavior

Agile mangabeys are quadrupeds and spend a significant amount of time in both arboreal and terrestrial environments. They spend 12 to 22 percent of their time on the forest floor, especially when traveling or feeding. Males, however, spend more time on the ground than do females. Groups are composed of 7 to 22 individuals that include one or, occasionally, several males along with multiple females. Groups are led by a single male. If multiple males do occur, they generally avoid one another. Smaller groups may also come together to form larger groups during the peak of the rainy season and again at the start of the dry season. Non-reciprocal grooming does occur within groups, and females typically groom only juveniles. Dominance hierarchies exist in agile mangabey groups, and dominant individuals will sometimes mount subordinate individuals outside of a sexual setting in order to establish dominance. ("Agile Mangabey", 2007; Fleagle, 1999; Groves, 1978; Richardson, 2009)

  • Average territory size
    1.98 km^2

Home Range

Agile mangabeys have home ranges of just under 2 square kilometers, which they are sometimes known to defend. (Groves, 1978)

Communication and Perception

Agile mangabeys communicate primarily through visual and auditory signals, but they may also use olfactory and tactile signals as well. Vocal communication is particularly important in a forested environment when danger calls emitted by one member of a group can alert the rest to the presence of a predator or communicate the group's position to other neighboring groups. Visual communication is typically used in interactions between members of the same group. Aggression, for example, is displayed through a combination of staring, raising the eyebrows, flashing the eyelids, bobbing the head, and opening the mouth while the teeth remain covered by the lips. Sexual readiness is indicated through "pouting." Olfactory communication is limited to pheromone production. Males, for instance, can check a female's estrous status by sniffing her when she presents to him. Tactile communication is limited primarily to instances in which one individual mounts another for non-sexual reasons; presenting for non-sexual reasons is linked to the pacification of dominant individuals by subordinate individuals. Like all primates, they perceive the world around them using smell, touch, taste, hearing, and, especially, vision. ("Agile Mangabey", 2007; Flannery, 2007; Richardson, 2009)

Food Habits

Agile mangabeys are generalized omnivores that feed on plant, fungi, and animal material. They prefer both ripe and unripe fruits and, particularly, old hard nuts and seeds that they open with their robust molars and thickened enamel. These nuts may be found on the ground or buried beneath and even in elephant dung that the monkeys go through. Furthermore, agile mangabeys have large incisors and particularly strong jaw muscles that can be used to crack open fruits and pods too tough for other sympatric species of monkeys. Besides fruit, nuts, and seeds, agile mangabeys consume leaves, monocotyledon hoots, the terminal tips of herbs and grasses, roots, fungi, buds, bird eggs, insects, and occasional vertebrates. Animal matter represents a significant part of their diet. Agile mangabeys are reported to spend 26 to 30 percent of their feeding foraging only for insects and have been known to kill vertebrates as large as young antelope. Like all "cheek pouch" monkeys, agile mangabeys are capable of gathering food into pouches in their cheeks to be saved for consumption later on. ("Agile Mangabey", 2007; Fleagle, 1999; Hart, et al., 2009; Richardson, 2009)

  • Animal Foods
  • mammals
  • eggs
  • insects
  • Plant Foods
  • leaves
  • roots and tubers
  • seeds, grains, and nuts
  • fruit
  • Other Foods
  • fungus

Predation

Non-human predation on agile mangabeys is relatively low because of the environments in which these monkeys typically live. Terrestrial predators can not easily hunt in swampy or flooded areas, and predatory birds can not easily pick off animals living in dense undergrowth. However, leopards (Panthera pardus), pythons (Python), and crowned eagles (Stephanoaetus coronatus) are all known to feed on agile mangabeys to some extent. Agile mangabeys are also hunted by humans as a sources of bush meat.

Anti-predator adaptations of this species, aside from its difficult environment, include alarm-calling. The particular alarm call of the agile mangabey is a long-series, high-frequency "chuckle." ("Agile Mangabey", 2007; Burton and Burton, 2002; Flannery, 2007)

Ecosystem Roles

The primary role that Cercocebus agilis likely plays in its environment is that of seed disperser. Since agile mangabeys specialize in breaking open and eating particularly tough fruits, seed pods, and nuts (many of which may remain on the forest floor for years before being eaten), it is likely that these monkeys play some role in the reproduction of the species of plants to which the fruits, nuts, and seed pods belong. They almost certainly affect the populations of the insects that they eat, since these make up a significant portion of their diet, and they probably have some small affect on small vertebrate populations within their home ranges. Agile mangabeys are also prey for larger predators.

Agile mangabeys serve as hosts for a variety of parasitic species. In a study published in 2002 and conducted on a variety of humans and non-human primates living in a park in the Central African Republic, agile mangabeys were found to host at least 7 different kinds of parasites, including ascaroid and strongylate helminths, trichomonads,and various protozoa. ("Agile Mangabey", 2007; Burton and Burton, 2002; Hart, et al., 2009; Lilly, et al., 2002; Richardson, 2009)

  • Ecosystem Impact
  • disperses seeds
Commensal/Parasitic Species
  • Entamoeba histolytica
  • Entamoeba coli
  • Balantidium coli
  • Iodamoeba butschii

Economic Importance for Humans: Positive

Agile mangabeys are sometimes hunted for bushmeat. (Richardson, 2009)

  • Positive Impacts
  • food

Economic Importance for Humans: Negative

Agile mangabeys are likely carriers of some human diseases or, at least, or strains closely related to human versions of the same disease. These include T-cell leukemia virus and probably Simian Immunodeficiency Virus as well. Since agile mangabeys are hunted for bushmeat, the potential for mutated strains of these viruses to jump hosts and spread to human populations is greatly increased. This species is also viewed by locals in the areas where it lives as a crop pest. (Courgnaud, et al., 2004; Hart, et al., 2009; Peeters, et al., 2009)

  • Negative Impacts
  • injures humans
    • carries human disease
  • crop pest

Conservation Status

Cercocebus agilis has a steady population and is not considered in current danger of extinction. However, deforestation is a potential threat to those populations not living in protected areas, and the Association of Zoos and Aquariums has set up a Species Survival Plan for them. These animals are also occasionally killed for their meat and as pests. (Hart, et al., 2009; Richardson, 2009)

Contributors

Kayla Weidman (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor, Tanya Dewey (editor), Animal Diversity Web.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

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.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

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.

food

A substance that provides both nutrients and energy to a living thing.

iteroparous

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).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polygynous

having more than one female as a mate at one time

rainforest

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.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

2007. "Agile Mangabey" (On-line). Mangabey SSP. Accessed April 09, 2009 at http://www.mangabeyssp.org/Agile%20Mangabey.htm.

Burton, M., R. Burton. 2002. International Wildlife Encyclopedia, 3rd Ed.. New York: Marshall Cavendish.

Courgnaud, V., S. Van Dooren, F. Liegois, X. Pourrut, B. Abela, S. Loul, E. Mpoudi-Ngole, A. Vandamme, E. Delaporte, M. Peeters. 2004. Simian T-Cell Leukemia Virus (STLV) Infection in Wild Primate Populations in Cameroon: Evidence for Dual STLV Type 1 and Type 3 Infection in Agile Mangabeys (Cercocebus agilis). Journal of Virology, 78(9): 4700-4709. Accessed April 10, 2009 at http://jvi.asm.org/cgi/content/full/78/9/4700.

Flannery, S. 2007. "Agile Mangabey (Cercocebus agilis)" (On-line). The Primata. Accessed April 10, 2009 at http://www.theprimata.com/cercocebus_agilis.htm.

Fleagle, J. 1999. Primate Adaptation and Evolution, 2nd Ed.. San Diego: Academic Press.

Groves, C. 1978. Phylogenetic and Population Systematics of the Mangabeys (Primates: Cercopithecoidea). Primates, 19(1): 1-34.

Hart, J., T. Butynski, J. Kingdon. 2009. "Cercocebus agilis" (On-line). 2008 IUCN Red List of Threatened Species. Accessed April 10, 2009 at http://www.iucnredlist.org/details/136615.

Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. San Diego: Academic Press.

Lilly, A., P. Mehman, D. Doran. 2002. Intestinal Parasites in Gorillas, Chimpanzees, and Humans at Mondika Research Site, Dzanga-Ndoki National Park, Central African Republic. International Journal of Primatology, 23(3): 555-573.

McGraw, W., J. Fleagle. 2006. Biogeography and Evolution of the Cercocebus-Mandrillus Clade: Evidence from the Face. Pp. 201-224 in S Lehman, J Fleagle, eds. Primate Biogeography. New York: Springer.

Peeters, M., V. Courgnaud, B. Abela, P. Auzel, F. Bibollet-Ruche, S. Loul, F. Liegeois, C. Butel, D. Koulagna, E. Mpoudi-Ngole, G. Shaw, B. Hahn, E. Delaporte. 2009. "Risk to Human Health from a Plethora of Simian Immunodeficiency Viruses in Primate Bushmeat" (On-line). Centers for Disease Control and Prevention. Accessed April 10, 2009 at http://www.cdc.gov/ncidod/EID/vol8no5/01-0522.htm.

Richardson, M. 2009. "Agile Mangabey (Cercocebus agilis)" (On-line). ARKive. Accessed April 10, 2009 at http://www.arkive.org/agile-mangabey/cercocebus-agilis/.