... ...

Episode 324: Red Colobus Collapsing

Listen on Apple Podcasts

The cute red colobus (image from madisonmagazine.yourwebedition.com)

Hailing from Africa, the Red Colobus Monkey belongs to the Old World Monkeys, the name given to those primates that evolved out of and live in Africa, the Middle East, and South and East Asia. Colobus monkeys are incredibly diverse and fall into three main groups, red, olive and black and white colobus, which are further grouped into Piliocolobus, Procolobus and Colobus genera. The name colobus actually derives from an ancient Greek word for mutilated, as unlike many other primates, they lack thumbs!

The multiple colour morphs of the different colobus subspecies (image from rewild.org)

Swingin’ through the treetops: the ecology of the Red Colobus

Red colobus monkeys are predominantly arboreal, spending most of their life in the trees, rarely descending to the ground of the humid forests they inhabit. They are incredibly important for the health of the forest, as they are important seed dispersers for the fruit that makes up a large part of their diet. Most of the subspecies prefer humid tropical forests, but the Zanzibar Red Colobus prefers to live in coastal thickets and scrub land.

Red colobus territory is well defined and defended, with a troop consisting of a dominant male with several females and their young. Males will stay with the group for a while after birth, but eventually disperse away. Fighting is a pretty rare occurrence, but when new males chase away the old male, there is often a spate of infanticide.

Two colobus monkeys eating charcoal (image from Youtube.com)

Red colobus have some really fascinating physiology that is pretty rare among monkeys. They have a multichambered stomach just like cows that helps them to feed on difficult to digest foods like seeds and leaves. The Zanzibar Red Colobus also has some incredibly unique after dinner snacks; charcoal. These monkeys have been seen eating charcoal from charred tree stumps and logs, the only primates aside from humans known to do so. Charcoal is very good at absorbing toxic compounds naturally occurring in their food that can interfere with digestion. Researchers suspect this behaviour has evolved as the Zanzibar Red Colobus lives in an area with a high abundance of mango and almond trees, whose leaves are high in chemicals called phenolics, which can upset digestion when ingested in large amounts. Eating charcoal from burnt trees will help the monkeys keep their digestion running smoothly, ensuring they get enough nutrients from their food.

The fascinating stomach of the Red Colobus monkey (image from Nijboer, 2006)

The crashing colobus: one of the most threatened primates in the world

Colobus monkeys are determined to be the most threatened non-ape primates in mainland Africa. 14 of the 18 defined taxa are classified as critically endangered, with the rest classed as endangered. Despite this, only 2 species are listed on CITES appendix 1, which prevents all trade in the animal or its body parts; P. kirkii (Zanzibar Red Colobus) and P. rufomitratus (Tana River Red Colobus).

Red colobus monkeys are massively threatened by illegal hunting for the wildlife trade, both for their fur and their meat. Sadly, they are known in hunting circles as one of the easiest monkeys to hunt, as they are easy to find, with troops both large and incredibly noisy. They don’t adapt well to hunting pressures; typically they don’t flee when humans approach, unlike some other, cannier primates that have rightly learned to be wary of humans. They are relatively large as monkeys go, making them popular with bushmeat hunters as they provide a lot of meat and have beautiful coats that can also be sold for high profits. Sadly, bushmeat hunting and illegal wildlife trading rose sharply through the COVID-19 pandemic and is still ongoing, as lockdowns devastated people’s ability to make enough money to support themselves. Eco-tourism dried up and supply chains ground to a halt, leaving some of the world’s poorest populations struggling. Many turned to the illegal wildlife trade to make money, whilst others simply turned to bushmeat to prevent themselves and their families from starving. With people’s ability to travel and move around severely restricted, less law enforcement in biodiversity and trading hotspots allowed heavy illegal hunting and trading to go unrestricted. As wildlife numbers decline, the demand for bushmeat and other wildlife products increases, as does the price. For these incredibly poor communities, we can hardly be surprised they have turned to illegal wildlife trading after years of economic and social devastation. This issue is a particularly complex and hard to solve problem. In addition to these intense hunting pressures, vast habitat loss and degradation for logging, mining, charcoal production and conversion of land for infrastructure and agriculture is pushing these charismatic monkeys into smaller and smaller fragments. Red Colobus are often referred to as the canary in the coal mine, as they are usually an early indicator of habitat damage and biodiversity loss in an area.

An artists rendition of the suspected extinct Miss Waldron’s Colobus (image from http://www.primate-sg.org/)

Two subspecies of Red Colobus are already expected to be extinct, although some scientists believe they may still exist in some isolated forest pockets. The wonderfully named Miss Waldron’s Red Colobus was last sighted in 1978 and was once present throughout Ghana and the Ivory Coast, and is now classed as one of the world’s top 25 most wanted species. Evidence from hunters in 2000 and 2001 revealed that the species could still be around. The Semiliki Red Colobus was only described in 1991 and was already on the brink of extinction then. This species also hasn’t been seen for years, but a 2019 survey in Uganda found Red Colobus monkeys in a previously unknown area, although no one could adequately identify them as the Semiliki species.

Conservation Optimism

Despite their dire situation, the Red Colobus is getting a lot of help and support from the conservation community. A 2021-2026 conservation action plan is currently underway, aiming to improve knowledge of their distribution and abundance and to establish new conservation areas with government support. There is also a program to engage locals with Red Colobus conservation, offering better healthcare in return for local involvement with conservation programs.

The IUCN led conservation plan for the Red Colobus (image from IUCN.org)

Encouragingly, recent studies revealed that the Zanzibar Red Colobus, the smallest sub-species, is actually doing better than expected, although their populations are still a concern outside of the protected areas they inhabit. In Jozani Chwaka National Park, where there are large populations of the Zanzibar Red Colobus, a study found that installing speed bumps could decrease mortalities from road traffic accidents, one of the most common causes of death of monkeys in that region. The inclusion of speed bumps around the parks entrance has seen massive decreases in Red Colobus deaths, and the scheme is likely to be rolled out throughout more of the park. This park has also been fairly successful in engaging locals in the mitigation of human-wildlife conflict, as Colobus monkeys are often blamed for crop raiding.

A troupe of Zanzibar Red Colobus (image from pinterest.com)

Red Colobus are classed as ‘cinderella species’, as they are considered to be fairly overlooked but aesthetically pleasing and lets be honest, super cute, making them a charismatic species that can front conservation efforts. Their range overlaps with 75% of all other African primate species, so their conservation could help to protect so many other species.

The not-for-profit ReWild are working with a group of international and cross-disciplinary groups to the develop the Red Colobus Conservation Action Plan (ReCAP) with the African Primatological Society and the IUCN Primate Specialist Group. This action plan includes a range of goals, like developing the next generation of conservation professionals, increasing political support, developing and implementing better technology like drones to tackle wildlife crime and more accurately survey colobus populations.

The African Wildlife Foundation, another conservation charity, has been developing the use of geographical mapping systems and other technologies to identify the most threatened areas and find those habitats with the most potential for supporting expanding populations of monkeys. They also work in close association with local communities, such as providing them with different seed varieties and teaching them better agricultural techniques, reducing wasted land that can be rehabilitated for the monkeys to frolic safely in.

Awesome videos!


Home | African Wildlife Foundation (awf.org)

Davenport, R.J. (2000) ‘Where have you gone, Miss Waldron’s Red Colobus?’ Science.

Davenport, R.B. Fakih, S.A. Kimiti, S.P. Kleine, S.P. Foley, L.S. and De Luca, D.W. (2017) ‘Zanzibar’s endemic red colobus Piliocolobus kirkii: first systematic and total assessment of population, demography and distribution.’ Oryx.


Linder, J.M. Cronin, D.T. Ting, N. Abwe, E.E. Davenport, T.R.B. Detwiler, K.M. Galat, G. Galat-Luong, A. Hart, J.A. Ikemeh, R.A. Kivai, S.M. Kone, I. Kujorakwinja, D. Maisels, F. McGraw, W. Oates, J.F. and Struhsaker, T.T. ‘Red colobus (Piliocolobus) conservation action plan 2021-2026.’ IUCN

Nijboer, J. Clauss, M. (2006) ‘The digestive physiology of Colobine Primates.’

Oates, J.F. Abedi-Lartey, M. McGraw, W.S. Struhsaker, T.T. and Whitesides, G.H. (2001) ‘Extinction of a West African Red Colobus Monkey.’ Conservation Biology

Olgun, H. Mohammed, M.K. Mzee, A.J. Green, M.E.L. Davenport, T.R.B. and Georgiev, A.V. (2021) ‘The implications of vehicle collisions for the Endangered endemic Zanzibar red colobus Piliocolobus kirkii.’ Oryx

Tan, J. (2020) ‘Bushmeat Hunting: the greatest threat to Africa’s wildlife?’ Mongabay

Struksaker, T.T. Cooney, D.O. and Siex, K.S. (1997) ‘Charcoal consumption by Zanzibar Red Colobus Monkeys: its function and ecological demographic consequences.’ International Journal of Primatology

Vyawahare, M. (2021) ‘No monkey business: For Zanzibar’s red colobus, speed bumps are lifesavers.’ Mongabay


March 15, 2023
Scroll to top