Pennant's colobus or Pennant's red colobus (Piliocolobus pennantii)
Pennant's colobus or Pennant's red colobus (Piliocolobus pennantii) is a species of tree-dwelling primate in the family Cercopithecidae. It is endemic to tropical Central Africa. Three subspecies have traditionally been recognised but its distribution is peculiarly disjunct and has been considered a biogeographical puzzle, with one population on the island of Bioko (Equatorial Guinea), a second in the Niger River Delta in southern Nigeria, and a third in east-central Republic of Congo. It is found in rainforests and marshy forests. It is threatened by habitat loss and hunting for bushmeat.
Taxonomy and etymology
Pennant's colobus was first described in 1838 by George Robert Waterhouse, curator at the Zoological Society of London's museum, and was named in honour of the naturalist and traveller Thomas Pennant. Three subspecies of this red colobus are traditionally recognized: The Bioko red colobus (Procolobus pennantii pennantii), the Niger Delta red colobus (Procolobus pennantii epieni) and Bouvier's red colobus (Procolobus pennantii bouvieri). However, Groves (2007) raised Piliocolobus pennantii epieni, and Piliocolobus pennantii bouvieri to Piliocolobus epieni and Piliocolobus bouvieri, respectively (this nomenclature has been followed here). Ting agreed that preliminary genetic evidence supported elevating Piliocolobus epieni at least.
The word "colobus" comes from Greek κολοβός, meaning "cut short", and is so named because of the significant reduction in size, or complete lack of an opposable thumb in comparison to other primates. To make up for this, they have four long digits that align to form a strong hook, allowing them to easily grasp branches and climb.
Description
Piliocolobus pennantii is a species of catarrhine primate in the family Cercopithecidae. Piliocolobus pennantii is a medium-sized primate, with a body length of 53 to 63 cm and a tail of 60 to 70 cm. It weighs between 7 and 10 kg. The head is small and the limbs are very elongated. The toes are long, with the thumb not extended. The colour varies in the different subspecies, in general the coat is black or dark brown, the muzzle and limbs are brown or reddish, the belly is light brown. The tail is very long, used for balance.
Distribution
Piliocolobus pennantii is found in several isolated localities in West Central Africa. The subspecies named Piliocolobus pennantii pennantii pennantii is endemic to Bioko Island, an area of only 32 km, located off the coast of Equatorial Guinea. The subspecies Piliocolobus pennantii bouvieri is found in the Republic of Congo, on the right bank of the Congo River. Piliocolobus pennantii epieni is found in the Niger Delta in Nigeria. It inhabits both primary and secondary rainforests, as well as swampy areas.
Life and reproduction
Forms large groups of twelve to eighty individuals, covering an area of up to 25 to 150 hectares. Includes several males and many females with young. They spend most of their time in trees. Gestation lasts about five months and there is usually one offspring per litter.
Diet consists mainly of fresh leaves, but also flowers, fruits and seeds. The stomach is multi-chambered and adapted to digest fresh plant foods.
Piliocolobus pennantii in the Red Data Book
The species is highly vulnerable due to natural habitat destruction and hunting. One of the subspecies, Piliocolobus pennantii bouvieri, is considered critically endangered; although its presence in the wild was documented in 2015, it may be on the verge of extinction.
The International Union for Conservation of Nature has designated the nominate subspecies Piliocolobus pennantii as "Endangered" because it has a range of less than 500 km2 and is hunted. The subspecies Piliocolobus epieni is Critically Endangered, as its population has declined by more than 80% in 30 years; the subspecies Piliocolobus bouvieri is also Critically Endangered, as it has not been seen in the wild since the 1970s until 2015, when there was photographic evidence of its presence in a national park in the Republic of Congo, but it is believed to be on the brink of extinction.
Status
The nominate subspecies Piliocolobus pennantii pennantii is listed as "Endangered" by the IUCN in its Red List of Threatened Species because its range on the island of Bioko is less than 500 square kilometres (190 sq mi) and its population size is decreasing due to it being hunted for bushmeat. In 2006, the population on Bioko Island was estimated to be smaller than 5000 individuals. The Niger Delta red colobus is listed as "Critically Endangered" due to the fact that its habitat in the Niger Delta is being degraded by logging and the monkeys are hunted for food. Its population has declined by 80% during a period of thirty years. The Bouvier's red colobus has declined dramatically in numbers and is also listed as "Critically Endangered", although its status was elevated to "Endangered" in 2019. After not having been seen since the 1970s, it was considered possibly extinct until spotted and photographed in 2015 in Ntokou-Pikounda National Park in the Republic of the Congo (the first photograph of Piliocolobus bouvieri). The subspecies is likely on the brink of extinction.
