Red colobus[1]
Zanzibar red colobus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Cercopithecidae
Subfamily:	Colobinae
Genus:	Procolobus
Subgenus:	Piliocolobus Rochebrune, 1877
Type species
Simia (Cercopithecus) badius Kerr, 1792
Species
Procolobus badius Procolobus pennantii Procolobus epieni Procolobus preussi Procolobus tholloni Procolobus foai Procolobus tephrosceles Procolobus gordonorum Procolobus kirkii Procolobus rufomitratus

Red colobuses are Old World monkeys of the subgenus Piliocolobus in genus Procolobus. Some authors elevate Piliocolobus to a full genus, limiting Procolobus to the olive colobus.^[1] They are closely related to the black-and-white colobus monkeys (genus Colobus) and some species are often found in groups with the blue monkey.^[2] The western red colobus is frequently hunted by the common chimpanzee.^[3]

The members of this subgenus are found in western, central and eastern Africa, and the species have largely allo- or parapatric distributions. Most are restricted to humid forests, but the Zanzibar red colobus prefers coastal thickets and scrub. Red colobuses are primarily arboreal and are highly sensitive to hunting and habitat destruction, and have been referred to as probably the most threatened taxonomic group of primates in Africa.^[4] If following the taxonomic treatment advocated in Mammal Species of the World,^[1] all species except the Central African red colobus are assessed by the IUCN as Endangered or Critically Endangered.^[5]

  Social behavior

Groups often establish a dominance hierarchy determined by aggressive behavior. Food, grooming, and sexual partners are distributed amongst higher ranking individuals initially, followed by lower ranking individuals.^[6]

  Diet

The diet of the red colobus monkeys consists mainly of young leaves, flowers, and unripe fruit.^[7] They are also known to eat charcoal to help combat the cyanide some leaves may contain. However, their stomachs are able to digest some toxic plants that other primates cannot.^[7]

  Chimpanzee predation

Research indicates that chimpanzee predation may be a major selection factor upon some red colobus populations.^[8] Although chimpanzees primarily eat fruit, leaves, and insects, if the opportunity to eat meat rises, they will pursue it. In addition to sustenance, evidence suggests that chimpanzees prey on red colobus to reinforce social status as well as to attract sexual partners.^[9] When under attack, the red colobus males congregate to defend their group while the females gather their infants and try to escape. Larger groups of red colobus have an increased likelihood of attracting chimpanzees, however they also tend to have more defending males which makes it harder for chimpanzees to hunt successfully.^[10] Furthermore, while under attack, male colobus shout an alarm call that lets others know if there are chimpanzees or other predators in the area. The frequency of these shouts are increased with the number of females and infants in the group as a way to spread the news of an expected attack.^[11]

  Species

• Western red colobus, Procolobus badius
• Pennant's colobus, Procolobus pennantii
• Niger Delta red colobus, Procolobus epieni
• Preuss's red colobus, Procolobus preussi
• Thollon's red colobus, Procolobus tholloni
• Central African red colobus, Procolobus foai
• Ugandan red colobus, Procolobus tephrosceles
• Uzungwa red colobus, Procolobus gordonorum
• Zanzibar red colobus, Procolobus kirkii
• Tana River red colobus, Procolobus rufomitratus

  References