Census reveals 65 percent increase in the number of 'endangered' African monkeys

The population of rare east African kipunji monkeys, recently thought to be on the brink of extinction, has increased by 65 percent in little over a decade thanks to efforts to protect the forests where these creatures live, in Tanzania’s southern highlands.

The kipunji is a rare and secretive monkey that was revealed to science in 2003. © Tim Davenport

When the kipunji – a medium-sized monkey with a dark face, long greyish-brown fur and a broad tuft of hair that stands erect on the top of its head – was first discovered in 2003, it was the first new monkey described in Africa in more than 80 years.

A census carried out four years later found its entire population was just 1,117 individuals. Their forest habitat on the slopes of Mt Rungwe, an inactive volcano that is also one of Tanzania’s highest peaks, and Livingstone Forest inside the Kitulo National Park, was severely threatened by hunting and illegal timber logging and charcoal production.

Years of work

But following years of work with local populations a survey carried out over a number of months between 2019-2020 by research teams from the Wildlife Conservation Society’s (WCS’s) Tanzania programme discovered a huge increase in numbers.

“We estimate a 65 percent increase in individuals, a 59 percent increase in group numbers, and a 19 percent increase in area of occupancy,” the research team wrote in a paper published in the International Journal of Primatology. 

The WCS and its partners have worked for a decade and a half to save the monkeys and the forests by improving protection and management of the areas, hiring and training forest rangers, supporting the livelihoods of local villagers and setting up local wildlife clubs and environment committees, among other measures.

"To see all our hard work over so many years pay off in terms of kipunji numbers and forest health is incredibly satisfying," said Tim Davenport, a former director of the WCS and the lead author of the latest study.

Hidden from science

To collect the data, research teams from the WCS used the same methods as in the 2007 survey. They spent nearly 12 hours a day armed with binoculars, maps and GPS units walking on foot along animal trails and human tracks and scanning the tree canopy.

They covered more than 1,400 kilometres to get the latest total of 1,866 individual monkeys. The survey also detected a massive decline in illegal logging and charcoal-making. In Mount Rungwe alone there was a 100 percent reduction in the use of charcoal pits, and a 98 percent reduction in timber felling.

The study predicts a further doubling of the kipunji population in the next 25 years "if current habitat protection continues".

Livingstone Forest, in the Kitulo National Park, is a kipunji stronghold. © Wikimedia Commons/Jojona

The kipunji are secretive and live mostly near the crowns of trees. Although the species was known to hunters – who first gave them the name kipunji – they remained hidden from science until Davenport and his survey team stumbled upon a dead kipunji caught in a farmer’s trap on Mount Rungwe in 2003.

Initially it was thought to be a species of mangabey, another type of monkey, but DNA analysis revealed that the kipunji belonged to a genus all of its own – Rungwecebus – named in honour of the monkeys’ volcano home.

Rivers revived

Colin Chapman, a primatologist and conservationist who has worked for more than 30 years in Uganda but was not involved with the kipunji study, described the WCS’s long-term efforts to census the kipunji as "remarkable".

"It is only by monitoring the true impact of conservation efforts on changes in population status that we can learn what approaches work and which ones do not," said Chapman, who is currently a fellow at the Wilson Centre in the US. 

Back in Tanzania Davenport, who has now left the WCS after 22 years of service, told RFI he had witnessed first-hand the improvements wrought by conservation in the kipunjis' highland home. 

"When I first climbed up Mt Rungwe in 2000, the forest was heavily degraded. There was so much logging and cutting for charcoal and there were huge gaps in the forest everywhere," he said.

"Now the canopy is almost completely closed and the streams and rivers are holding a lot more water too."