Pennant's red colobus are arboreal and spend the majority of their lives in the treetops. They can be found at all levels of the canopy in both primary and secondary rainforest. This genus of monkey occurs in higher densities in primary forests than other genera of Colobinae. Some Pennant's red colobus are also found in marsh forests. Unlike members of a similar genus g. Colobus (black and white colobus), Pennant's red colobus are not found in dry forests. In general, this species is found at relatively high elevations. ("The Primata", 2007; Fleagle, 1988; "Honolulu Zoo", 2008; Richardson, 2003)
One of the most striking features of colobus monkeys is their lack of thumbs. A bump remains where the thumb should be, making it look as though the thumb has been cut off. To allow climbing, the other fingers are elongated and form a hook to grip branches. As with many climbing mammals, the limbs of Pennant's red colobus are also elongated. In general, male Pennant's red colobus tend to be larger than females. This speices ranges in mass from 7 to 11 kg. The length of the head and body is usually between 53 and 63 cm, while the tail ranges from 60 to 70 cm. The head tends to be rather small and the belly is round. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998; "Honolulu Zoo", 2008; Kavanagh and Morris, 1984; Richardson, 2003)
Subspecies of Pennant's red colobus vary in the coloration of their pelage. The shaggy hair varies between shades of maroon and orange. The crown is usually dark red to nearly black, and the back feet and tail tend to be dark brown. White is often found on the hair of the pubic region. The hair on the forehead is distinctly parted down the center. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998; "Honolulu Zoo", 2008; Kavanagh and Morris, 1984; Richardson, 2003)
Not much is known about the reproduction of Pennant's red colobus, though the reproduction of other species in the subfamily Colobinae is likely similar. The genital area of females swells during estrus. Females use "social presenting" to signal that they are ready to mate. Colobus monkeys breed in a sort of "communal marriage" in which females ready to mate and males retreat from the larger group. Colobus monkeys are polygynous, meaning each male breeds with multiple females. ("The Primata", 2007; "Honolulu Zoo", 2008; Richardson, 2003)
There is no specific breeding season for colobus monkeys, and females give birth approximately every two years. Pennant's red colobus give birth to one offspring at a time. The gestation period of this particular species is not known, but the gestation period of other colobus monkeys ranges from five to seven months. After gestation, female colobus monkeys leave the group, accompanied by a single male, and do not return until a day after the birth. In Africa, female Colobinae tend to reach sexual maturity between 3 and 4 years and males between 5 and 6 years. ("The Primata", 2007; "Honolulu Zoo", 2008; "Singapore Zoological Gardens Docents", 2000)
For the first 1 to 3.5 months after birth of Pennant's red colobus, generally only the mother handles the infant. After this time, other group members help care for the young. Mother Pennant's red colobus allow their offspring to hang from their bellies for about 8 months. Young of both sexes have genital regions that mimic those of adult females. This is thought to protect unidentifiably male youth from being expelled from the group by adult males. ("The Primata", 2007; "Honolulu Zoo", 2008; "Singapore Zoological Gardens Docents", 2000)
Little information is available regarding the lifespan of Pennant’s red colobus monkeys. Other members of the subfamily Colobinae have been known to live 25 to 30 years. ("Bioko Biodiversity Protection Program", 1998; "Oregan Zoo Animals", 2005; "Singapore Zoological Gardens Docents", 2000)
Pennant's red colobus live in social groups composed of many males and females, usually with a high proportion females. Although females usually stay with the same group, males often move to a new group on several occasions throughout their lifetime. This behavior can result in some all-male groups. While larger groups occasionally displace smaller ones when competing for food, this species is not otherwise known to be territorial. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998; Richardson, 2003)
Pennant's red colobus can be described as both diurnal and arboreal. They move through the trees with quadrupedal motion, meaning they use all four limbs to walk along the branches. They also leap through the trees, sometimes using slim branches to launch themselves across breaks in the canopy. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998)
The home range of a group of Pennant's red colobus, which often overlaps with that of other groups, can extend 100 ha or more. (Fleagle, 1988)
Pennant's red colobus engage in three major social behaviors. The first of these is social presenting, in which the presenter faces its rear toward the receiver and lifts the hindquarters higher than the rest of the body. This act of submission is performed by all but the adult males. Social presenting usually leads to social mounting. The receiver of the social presenting responds by mounting the presenter in the same manner done during mating. Social mounting displays dominance and is done by all except the least dominant members of the group, infants. Social grooming often follows these behaviors. Through this process, unwanted material, such as dead skin, insects, or parasites, are removed from one individual by another, often using his or her mouth. While the hygienic aspect of this act is rather important, its true purpose is to strengthen the bond between those involved. Social grooming becomes more common when another group is near. Pennant’s red colobus are also known to be rather loud. Noises described as “barks” and “squawks” may be a very important auditory communication between individuals and between troops. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998)
Pennant's red colobus search for food in the upper division of the forest and tend to eat in the morning and again in the evening. Their diet consists of foliage in the form of immature leaves and shoots, as well as seeds and fruits. Colobus monkeys have complex stomachs capable of fermentation, allowing them to break down difficult plant materials like cellulose. Because of this fermenting process ripe, sugary fruits result in excess gas and acid formation when eaten. This causes pain and could result in death. Therefore, this species can only digest fruits that are unripe and tough. Pennant's red colobus have also been known to eat fungi and even termite clay. ("The Primata", 2007; "Bioko Biodiversity Protection Program", 1998)
Chimpanzees are a common predator of red colobus and can reduce populations by as much as 10 % in a year. The large social groups of red colobus are an anti-predatory defense. Some red colobus listen for warming calls of other species of monkeys to alert them to danger. Humans also hunt Pennant's red colobus for meat. (Fleagle, 1988; Strier, 2007)
Red colobus monkeys, including Pennant's red colobus, are preyed upon by chimpanzees. This species also acts as a seed disperser, as it consumes fruits and seeds. Social groups of Colobus monkeys compete with each other for food; the most successful competitors are often the largest groups. (Fleagle, 1988; Napier and Napier, 1970; "Singapore Zoological Gardens Docents", 2000)
Colobus monkeys are the only monkeys with a complex multichambered stomach containing cellulose-digesting bacteria. Because of this complex digestive system and relationship with bacteria, colobus monkeys are extremely successful in rainforest habitats in both Africa and Asia. Other Old World monkeys appear to be in direct competition with colobus monkeys for food. However, because of the unique digestive abilities of colobus monkeys, they eat very different proportions of shared resources, and competition is thus less extreme with other Old World monkeys. (Fleagle, 1988; "Singapore Zoological Gardens Docents", 2000)
The meat of Pennant's red colobus is commonly sold in commercial bushmeat markets. Growing African cities increases the need of animal protein, such as bushmeat. The bushmeat market in West Africa alone is a multibillion dollar industry. Sooty mangabeys, black and white colobus, and red colobus are especially at risk, because they provide hunters with the most profit. (Richardson, 2003; Strier, 2007)
There are no known adverse affects ofon humans.
Pennant's red colobus is considered critically endangered by the IUCN. Conservation International named the species as one of the “world’s 25 most endangered primate species” in 2006. A combination of habitat loss and hunting has resulted in low population sizes. Pennant's red colobus are sold in bushmeat markets, and are easy targets for hunters because they are both loud and slow. ("Bioko Biodiversity Protection Program", 1998; Richardson, 2003)
Pruess's red colobus (Piliocolobus pennantii pruessi) was once considered to be a fourth subspecies of Pennant's red colobus. However, some are now considering it to be an entirely separate species and have given it the new designation of Piliocolobus pruessi. (Richardson, 2003)
Kasi Gilbert (author), Northern Michigan University, John Bruggink (editor), Northern Michigan University, Gail McCormick (editor), Animal Diversity Web Staff.
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
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
helpers provide assistance in raising young that are not their own
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
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
An animal that eats mainly plants or parts of plants.
marshes are wetland areas often dominated by grasses and reeds.
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.
having more than one female as a mate at one time
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.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
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.
breeding takes place throughout the year
Bioko Biodiversity Protection Program. 1998. "Bioko Biodiversity Protection Program" (On-line). Pennant's Red Colobus. Accessed February 15, 2009 at http://www.bioko.org/wildlife/pennanti.asp.
Honolulu Zoo. 2008. "Honolulu Zoo" (On-line). Colobus Monkey. Accessed February 21, 2009 at http://www.honoluluzoo.org/colobus_monkey.htm.
Oregan Zoo, Portland, OR. 2005. "Oregan Zoo Animals" (On-line). Colobus Monkey. Accessed February 21, 2009 at http://www.oregonzoo.org/Cards/Rainforest/monkey.colobus.htm.
Singapore Zoological Gardens Docents. 2000. "Singapore Zoological Gardens Docents" (On-line). Colobines (Colobinae) African Colobus and Asian Langurs. Accessed February 15, 2009 at http://web.archive.org/web/20051203234858/http:/www.szgdocent.org/resource/pp/p-colobn.htm.
2007. "The Primata" (On-line). Pennant's Red Colobus (Procolobus pennantii). Accessed February 15, 2009 at http://www.theprimata.com/procolobus_pennantii.html.
Fleagle, J. 1988. Primate Adaptation and Evolution Second Edition. San Diego, California: Academic Press.
Kavanagh, M., D. Morris. 1984. A Complete Guide to Monkeys, Apes and Other Primates. New York: The Viking Press.
Napier, J., P. Napier. 1970. Old World Monkeys: Evolution, Systematics, and Behavior. New York, New York: Academic Press.
Richardson, M. 2003. "ARKive Images of life on earth" (On-line). Pennant's Red Colobus (Piliocolobus pennantii). Accessed February 15, 2009 at http://www.arkive.org/pennants-red-colobus/piliocolobus-pennantii/info.html.
Strier, K. 2007. Primate Behavior Ecology Third Edition. United States of America: Allyn and Bacon.