Bay Colobus

When predators, such as chimpanzees and leopards, are near, western red colobus call out. Immediately on detecting a chimpanzee, they call out in alarm but stop shortly thereafter. The group then climbs higher in the trees, up to strata 4 and 5, or higher than 26 m. When a leopard is spotted, western red colobus give an alarm call and several males then approach the leopard and drive it away. Western red colobus monkeys are also hunted by humans for their bushmeat and fur. The subspecies P.b. waldroni has been driven to or very near extinction by poachers because of their fur and meat. If P.b. waldroni is truly extinct, it would be the first recorded 20th century primate taxon to die off. There is, however, evidence of their continued existence, though this is limited to the forest between the Ehy Lagoon and Tanoe River of western Ghana.

Known Predators:

• chimpanzees Pan trogladytes
• leopards Panthera pardus
• humans Homo sapiens

Western red colobus are sexually dimorphic, and adult females are slightly smaller than adult males. Males weigh between 9.1 kg and 12.2 kg, whereas females weigh between 6.8 kg and 9.1 kg. Western red colobus are 45 to 67 cm in length, and their tail is an additional 52 to 80cm long. Their body is brown, grey or black in color, and their head and appendages are chestnut or red in color. Their pubic area is surrounded by white fur. Their coat is even in length. Western red colobus do not have a thumb, but rather have a bump in their place. They also have long fingers for grasping branches. In addition, male and female juvenile western red colobus exhibit similar genital swellings as mature females, and juvenile males do not yet show evidence of a penis or scrotum. There are three subspecies of Pilliocolobus badius, P.b. badius, P.b. temmincki, and P.b. waldroni, and each are slightly different in physical appearance. P.b. badius exhibit black foreheads and outer thighs, and they also possess an exterior nose elevetaed on a well padded base. P.b. waldroni possess more red on their outer thighs and forehead than P.b. badius.

Range mass: 6.8 to 12.2 kg.

Range length: 97 to 147 cm.

Sexual Dimorphism: sexes alike; male larger

Other Physical Features: endothermic ; bilateral symmetry

Western red colobus monkeys have about a 30% mortality rate in their first 6 months. Between 6 and 12 months of age, they have a mortality rate of 18%. Due to chimpanzee predation, mortality rates are 28% between 18 and 24 months of age. Because females migrate between groups and males do not, females have a higher mortality rate than males. The lifespan of western red colobus is currently unknown.

Western red colobus are found in old growth rain forests at all levels of the canopy, from the ground to stratum 5 of the tree canopy, which is the tops of developing trees greater than 40m above ground. Western red colobus monkeys spend most of their time in the third or fourth strata (20 to 30m). The subspeices P.b. Temmincki resides in mountain forests and tropical rain forests and are also adapted to the dry forests of Senegal. The subspecies P.b. waldroni inhabits dense, tall canopied forests.

Range elevation: 0 (low) m.

Average elevation: 20-30 m.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

As with some other species of primates, the posterior end of male western red colobus monkeys changes with age. Juvenile males display a swelling of the perineal organ to mimic that of a mature female during heat, though they are morphologically different. As fetuses and juveniles, western red colobus have a perineal organ that is bright pinkish-red, with a bright blue fake clitoris and some spots around the origin of the tail and anus. This vibrant coloration remains until maturity. The coloration of males changes drastically as they mature: the bright pinkish-red portion of the perineal organ turns a greyish-yellowish-red, and the bright blue darkens to a blueish-black. The perineal organ of males is covered with scaly keratinized skin that is stratified. Because juveniles look like adult females, they are protected against older, stronger males of the group.

Western red colobus monkeys use vocalizations to communicate. When predators, such as chimpanzees and leopards, are near, western red colobus call out. Immediately on detecting a chimpanzee, they call out in alarm but stop shortly thereafter. They then climb higher in the trees, up to strata 4 and 5, or higher than 26 m. When a leopard is spotted, western red colobus give an alarm call and several males then approach the leopard and drive it away. Juveniles exhibit a pink gential swelling much like the swelling of the adult females. This mimicry helps juveniles avoid confrontation with older, larger males of the group.

Communication Channels: acoustic

Other Communication Modes: mimicry ; choruses

Perception Channels: visual ; tactile ; acoustic ; chemical

Western red colobus monkeys are considered endangered by the IUCN. The subspecies P.b. waldroni is critically endangered and possibly extinct. Low population size is due to hunting for bushmeat and fur as well as habitat destruction from logging.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: endangered

There are no known adverse effects of Piliocolobus badius on humans.

Western red colobus monkeys are an important part of the bushmeat trade. It is difficult to enforce laws in national parks, where poachers hunt with little interference. The subspecies P.b. waldroni has been driven to or very near extinction due to poaching and the bushmeat trade. Western red colobus monkeys are also hunted for their coat, as they possess long fur with an appealing coloration.

Positive Impacts: food ; body parts are source of valuable material

Western red colobus monkeys are prey to chimpanzees and leopards. They may also act as seed dispersers during the dry season when they eat a higher proportion of fruits.

Ecosystem Impact: disperses seeds

Western red colobus monkeys are folivorous, consuming mostly young leaves but also mature leaves, seeds, unripe fruit and shoots. Members of the subspecies P.b. temmincki consume leaves of Terminalia macroptera, Celtis integrifolia, Erythrophleum guineense, Pterocarpus erinaceus and Dichrostachys glomerata as well as fruits and flowers at the end of the dry season when leaves have become hard. Western red colobus possess a unique digestive system in which a ruminant-like multi-chambered stomach digests cellulose.

Plant Foods: seeds, grains, and nuts; fruit; flowers

Primary Diet: herbivore (Folivore )

Western red colobus monkeys are found in western Africa. The subspecies P.b. badius, bay red colobus, is native to Cote d’Ivoire, Sierra Leone and Liberia. The subspecies P.b. waldroni, Miss Waldron's red colobus, is native to eastern Cote d’Ivoire and western Ghana. The subspecies, P.b. temminiki, Temminck's red colobus, is native to Senegal and is scattered through Guinea, Gambia and Guinea-Bissau.

Biogeographic Regions: ethiopian (Native )

Female western red colobus monkeys choose which male(s) with which to mate, as they migrate from group to group. It is uncertain whether this species is monogamous or polyandrous.

Female western red colobus monkeys give birth to a single offspring every two years. Females leave their natal group, moving freely between groups of males, which remain in their natal group. Males of different coalitions demonstrate aggression as they fight for the mobile females. When females are ready to mate, they develop eostrogen-dependent swollen genitals that resemble a pink rosebud. This is not a permanent change. It is uncertain whether female western red colobus monkeys mate with a single male or multiple males. Characteristic of the subspecies P.b. temminckii, a male and female withdraw from the group, and the female lies susceptible to the male for copulation. P.b. temmincki also show distinctive seasonal breeding. The gestation period of western red colobus monkeys is 6 to 6.5 months. Females of P.b. temmincki do not make any sounds during copulation, whereas females of P.b. badius females do vocalize while copulating.

Range number of offspring: 1 (low) .

Range gestation period: 6 to 6.5 months.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

Little information is available regarding parental investment of western red colobus monkeys, as they do not survive long enough to breed in captivity and few studies have focused on this aspect in the wild. General observations suggest no parental involvement occurs after birth. Mothers, however, defend, nurse and groom their offspring.

Parental Investment: altricial ; female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

Forming large polyandrous groups of between 12 and 80 individuals (1), the red colobus is diurnal (6). It spends the day moving through the top of the canopy looking for leaves, shoots, fruits, and fungi. It has a complex stomach divided into sacs, due to its diet. In the upper chamber of the stomach, foliage is fermented by bacteria, and once in the lower chamber it can be digested by acid. The stomach is particularly large so that it can take the large quantities of this low value food that are needed to provide the red colobus with the necessary energy and nutrients to survive. More than a quarter of the body weight of an adult can be attributed to the food in its stomach (6). Although not territorial, larger groups tend to have dominance over smaller groups when interactions occur. Mixed-sex groups contain more females than males, leaving bachelor groups of between 8 and 40 males. When ready to mate, females develop swollen genitals and will present to males to encourage mating. Each female may mate with many males, producing just one offspring every two years. Infanticide can occur, but the reasons for this are not fully understood. Once weaned, both males and females will leave the group, but females will join another mixed-sex group, whereas males may join a bachelor group. A social monkey, the red colobus conforms to a hierarchy, crouching to communicate submission, which may lead to 'social' mounting, not to mate, but as a prelude to social grooming (5).

The larger issues of habitat loss and the bushmeat trade underscore the red colobus' fight to exist. Both these problems rely on wide-ranging social and political change for their solution, and much is being done to counter them. Miss Waldron's colobus was declared extinct in 2000, becoming the first primate to go extinct in at least 200 years. However, the scientists who announced its extinction obtained evidence in 2004 of its possible existence, consisting of a tail, a skin and a photograph from hunters, providing new hope. The IUCN continue to classify this subspecies as Critically Endangered, since it has not satisfied the criteria stating that it is beyond reasonable doubt that the last individual has died (8).

The red colobus, like other colobus species, has just a bump in place of the thumb, indeed, colobus means 'docked' in Greek, but the other fingers are particularly long. This monkey differs from other colobus species as the fur is of even length over the whole body, with no tufts of longer fur. Whilst the subspecies differ in size and colouration, they are mainly black, grey or brown above with red or chestnut arms, legs and head (2). Around the pubic area the fur is white, and juveniles of both sexes have female-like genital swellings, possibly to prevent mature males evicting young males before they have matured (5). The red colobus does not have cheek pouches (6). Taxonomic relationships within this species, and with other taxa of red colobus, are widely debated by experts and require clarification.

The red colobus is found in tropical and gallery rainforests in all levels of the canopy (5).

The red colobus is found across much of Africa but the subspecies are confined to certain areas, many of which overlap. The Lomami red colobus (P. b. parmentieri), the Kisangani red colobus (P. b. langi), the Foa red colobus (P. b. foai), and the Kahuzi red colobus (P. b. lulindicus) are all found only in the Democratic Republic of Congo. Elliot's red colobus (P. b. ellioti) is also found in the Democratic Republic of Congo, and is thought to be extinct in Uganda. Miss Waldron's red colobus (P. b. waldronae) was found in Côte d'Ivoire and Ghana but has not been seen alive since 1978 (3). However, recent evidence of a tail, a skin and a photograph suggest that a handful of individuals have remained undetected to this point in the extreme southeast of Ivory Coast (7). The bay colobus (P. b. badius) is found in the western Ivory Coast, Liberia and Sierra Leone (1). Temminck's red colobus (P. b. temminckii) is found in Gambia, northern Guinea, Guinea-Bissau and southern Senegal (1) (3).

The red colobus is classified as Endangered (EN A1cd + 2cd, B1 + 2abc) on the IUCN Red List 2004 (3) and is listed on Appendix II of CITES (4), both as Procolobus badius. Subspecies: the bay colobus (P. b. badius) and Temminck's red colobus (P. b. temminckii) are classified as Endangered (EN A2cd + 3cd + 4cd), and Miss Waldron's red colobus (P. b. waldronae) is classified as Critically Endangered (CR A1c, C2a, D) on the IUCN Red List 2004 (3). The IUCN also recognise a further five subspecies: the Lomami red colobus (P. b. parmentieri), Elliot's red colobus (P. b. ellioti), the Kisangani red colobus (P. b. langi), the Kahuzi red colobus (P. b. lulindicus), and the Foa red colobus (P. b. foai), all classified as Data Deficient (DD) (3). However, recent scientific thought is that these colobus do not belong to Piliocolobus badius, but should be included as subspecies of a different species, P. foai (1).

Although hunting of the red colobus is illegal, it is still very common, with red colobus forming a fair proportion of the bushmeat trade. Compounding this major threat is the loss of huge tracts of forest, particularly along the Ivory Coast, where 85% of original forest cover has been lost (8).

The western red colobus (Piliocolobus badius), also known as the bay red colobus, rust red colobus or Upper Guinea red colobus, is a species of Old World monkey in West African forests from Senegal to Ghana. All other species of red colobuses have formerly been considered subspecies of P. badius. It is often hunted by the common chimpanzee. In 1994, western red colobus monkeys infected many chimpanzees with Ebola virus when the chimpanzees hunted the monkeys as prey.