The forests of Tanzania are home to hundreds of endemic animal species – those found no where else in the world. If we are to ensure the existence of these unique species we must protect their remaining habitat – something ARC has been doing for over twenty years. Every Wednesday, we will profile a different endemic species to give a peak into the amazing wildlife you can find in Tanzania’s forests. Think of it as a virtual safari! Thank you to ARC intern Nick Hummel who joins us from The New School to present this series.
Last week we profiled the Lesser Bush Baby. Today we explore the Red Colobus Monkey.
Three species of the Red Colobus Monkey are found in Tanzania and of these, two are endemic:
Udzungwa Red Colobus: found only in the Udzungwa Mountains of Tanzania
Zanzibar Red Colobus: found mainly on Zanzibar Island with a few other scattered populations in Tanzania
Eastern Red Colobus: found in Western Tanzania.
Red Colobus Monkeys are arboreal (tree-dwelling), diurnal (active during the day), and specialized herbivores (plant-eaters). The name Colobus originated from a word that means “mutilated” or “docked,” referring to the monkey’s lack of thumbs on its hands, something all species of Colobus monkeys have in common. This allows them to use their four long fingers to wrap around branches while they swing through the canopy.
The diet of the Red Colobus consists mainly of leaves from over 60 different plant and tree varieties, but they also supplement this with unripened fruit, shoots, flowers, and stems. Most animals can’t access the nutrition in leaves because they can’t digest them. But Red Colobus Monkeys have a large four-chambered stomach filled with beneficial bacteria, which allow them to ferment and break down the dense, cellulose filled leaves and also give them their pot-bellied appearance. Their long periods of inactivity (around seven of the ten hours they’re awake) are often attributed to the fermentation process occurring in their bellies. The build up of methane and carbon dioxide in their stomachs causes them to burp a lot, but, unlike humans, burping is seen as a friendly gesture! They have often been observed eating charcoal, an absorber of toxins, to aid in the digestion of leaves.
Like most primates, they are social animals and live in groups of up to 100 individuals. These large groups will then split off into smaller groups with one to two males each and forage for food but will always return to the larger community. They have specialized calls that communicate different messages used for mating and warning other individuals of danger. Some local people have noticed that Colobus monkeys become quiet when bad weather is on its way.
They have a relatively long nursing period for their young compared to other mammals, and only have one child at a time, which results in a low birth rate. The Zanzibar Colobus has a particularly long nursing period with males nursing for up to four years until they’re ready to mate. This is part of the reason why this species is facing population deficits. Yet this practice of longer nursing periods is an adaptation that gives the child a longer period to learn the skills it will need to communicate, feed, defend itself, and take care of its own child one day.
Their predators include chimpanzees, which will hunt them in packs, and occasionally crowned eagles will pick them out of the canopy. But they are alert and agile animals and can often avoid being caught.
The Udzungwa Red Colobus Monkey is considered endangered by the IUCN Red List of Threatened Species and is only found in the riverine and montane forests of the Udzungwa Mountains in Tanzania. The Zanzibar Red Colobus monkey is one of the most endangered species of primates in the world with less than 2,000 individuals remaining.
Threats and Solutions
Habitat destruction caused by logging, charcoal production, clear cutting for agriculture, bush-burning, and hunting by humans pose serious threats to the remaining populations of Colobus. ARC’s field partner, the Tanzania Forest Conservation Group (TFCG) has been sounding the alarm on the need to protect the Udzungwa Mountains. They predict that if trends are not swiftly reversed that the Udzungwa Red Colobus, along with other forest mammals, including duikers, will face extinction. TFCG is currently working with local partners, including government agencies, to upgrade the Udzungwa Forest Reserve to a Nature Reserve in order to provide additional protection to the forest and the animals who call it home. They are also implementing environmental education activities and creating forest patrols to help get the word out to local people about the need to protect this forest.