Diana Monkey Research in Gola

The Gola Forest Programme is carrying our research on the Diana Monkey.  The research is giving insight into its ecology so that we can understand it better and improve the conservation of this threatened species. Catherine Brewis tells us more....

Diana Monkey, by S.Nash/Conservation International

 Diana monkeys (Cercopithecus diana) typically live in groups of about 20-25 individuals with one adult male, 5-7 adult females and several sub-adults and infants. Their diet consists mainly of fruit, along with flowers, leaves, invertebrates and occasionally bark, soil or mushrooms. Due to the fact that they eat a lot of fruit, they swallow many seeds and therefore play a role in seed dispersal.

The IUCN Red List (http://www.iucnredlist.org) currently lists Diana monkeys as ‘Vulnerable’. This means that their numbers are decreasing due to pressures from human activities, such as hunting and logging. In Sierra Leone, Diana monkeys are protected by law and with the Gola Forest reserves acting as a haven for wildlife, it is hoped that their numbers will soon increase. Not only does the Diana monkey research team learn more about the monkeys’ ecology but we also provide a daily presence which ensures that our study group remains safe from hunters.

The research being carried out with the Diana monkeys in Gola East focuses on collecting data on their diet, their ranging patterns and their role as seed disperses. We identify the food items they eat by observing the monkeys through binoculars, we collect specimens, photographing them and pressing plants to create a reference collection. GPS points are taken every ten minutes when we are with the group in order to create a map of their home range and we monitor germination rates of seeds found in dung piles throughout the forest. We also have a seed nursery, where we have planted defecate seeds (seeds deposited in dung) and free falling seeds. Since monkey dung is a fertilizer and by passing through the stomach, the seeds are cleaned of parasites, it is expected that seeds deposited by the monkeys will germinate more quickly than free falling seeds.

In order to carry out this study we must first locate our monkey group, stay with them and collect data. Luckily, this particular group has been habituated for over a year and so they are accustomed to the presence of human observers. We can therefore spend quality time with them, learning more about their ecology.