New research on the eating habits of the elusive Peruvian woolly monkey (Lagothrix cana) can help conservationists plan strategies to boost populations of this little-known species.
Ruthmery Pilko Huarcaya is small and slight, softly spoken, but there’s a good reason why she has the reputation amongst other researchers for being tough.
Tracking woolly monkeys for a year through thick vegetation, in sweltering tropical heat and across the challenging terrain of the Amazon rainforest is a task that not many people can cope with. For Ruthmery, it was the day job.
There is a severe lack of information about this rare, endangered species mostly because tracking them is so difficult.
“In the beginning,” said Ruthmery, “I spent two months searching without seeing a single woolly monkey.”
The challenge of studying the species means there have only been two papers published on them, one from Brazil in the 1990s and another two years ago from Peru.
Peruvian woolly monkeys are wary of people because they have been heavily hunted and their infants are often taken as pets. Sticking with a group until they accept you is the major hurdle in studying their behaviour.
“After a while,” said Ruthmery, “I learnt that the woolly monkeys have particular pathways that they use, making it a lot easier to find them. It’s really interesting because their movements depend on which trees are fruiting each month. When a particular tree was fruiting, I knew that they’d always be in the area.”
While monitoring the woolly monkeys, Ruthmery noticed that they were eating small fruits whereas you would expect big primates to be eating large fruits. She also discovered that the monkeys had changed the composition of their diet; previous research had shown that in primary forest their diet would consist of 80% fruit, whereas in this regenerating forest it was 50% fruits with a greater amount of leaves and invertebrates.
Ruthmery was intrigued: had the woolly monkeys adapted their behaviour to survive in regenerating forests? Ruthmery decided to catalogue all the fruits that the woolly monkeys ate, registering over 100 different species.
“With this information we’ve collected we can predict if a certain regenerating forest is a suitable habitat for woolly monkeys, or what types of tree species need to be planted in a reforestation programme.”
This research was carried out thanks to funding from Rufford’s small grants scheme and was published as a field guide by Chicago Field Museum.
Filling in this knowledge gap about the diet of woolly monkeys will help conservationists plan strategies to help populations of species in other regenerating forests.
“The reason we wanted to produce the field guide”, Ruthmery explains, “is to encourage more people to get involved in the conservation of the species. The guide will be helpful for other primatology students or for practitioners involved in species conservation strategies.”
During her research, Ruthmery was based here at the Manu Learning Centre (MLC), a field research station and ecotourism site within the Manu Biosphere Reserve in the Amazon rainforest of south eastern Peru.
The MLC nature reserve is regenerating forest that was once logged to create farmland for cattle and agriculture, but is now a protected area and a safe haven for a wealth of wildlife.
The reserve is one of the few easily accessible areas where you can monitor Peruvian woolly monkeys, as there has been no hunting here for decades so the monkeys are less timid of people and accept them much more readily.
Here at the MLC, Ruthmery’s research has shown us that the three groups of woolly monkey that are found within the reserve, totalling 55 individuals, are playing an important role within the ecosystem. By moving between the primary and regenerating forest, the groups of monkeys are acting as important seed dispersers and they will increase the tree diversity of the regenerating forest.
For Peruvian researchers like Ruthmery, working at the MLC has allowed her to develop her skills.
“At university, it was all about the theory,” said Ruthmery, “so coming here really opened my eyes in so many ways. I was able to carry out practical field research, I was given support to apply for funding, there were volunteers here to help me so I could develop my project, I leant to speak English. There were so many opportunities here.”
Ruthmery is now writing up a paper on her research into Peruvian woolly monkeys and continues to work at the MLC on the Tree Top Manu project.
Featured photo: Marcus Brent-Smith