You just never know what you’ll find in the rainforest trees of northeastern Peru – especially when you’re looking for monk sakis, small monkeys that kind of look like masked Mexican wrestlers wearing oversize raccoon coats.
They’re what Winthrop University biology professor Janice Chism was looking for in 2008, and that’s what she found: They have dark fur frosted with white or gray. But she also found more – a different saki group whose females have grayish fur but whose males have reddish-brown fur around their faces.
What Chism discovered could be a new saki species – potentially a hybrid of equatorial sakis, found in Ecuador and Peru, and monk sakis, whose range additionally extends to forests in Brazil, Columbia and Bolivia.
Chism said she and her team will need to work with a geneticist to study the DNA of saki monkeys to determine what of 16 recognized species are present in the Tahuayo River Amazon Research Center, the reserve where these different sakis were found.
And that’s not such an easy task.
Sakis, she said, are understudied: “Nobody really knew anything about them.”
Some research has been done on the species known as monk sakis, which are thought to be the dominant type in South America. Sakis often travel in groups of four to five individuals, usually a male, female and their young, Chism said. When children are between 3 and 4 years old, they leave to form their own groups. Sakis eat mainly unripe fruit and live in the middle canopy of the forest.
A couple of factors offer more complications.
• The reserve is a sprawling and remote tract. Its website notes, “The trail grid behind the research center lodge covers 52 miles spread over 1000 acres. It is the largest trail system offered in the Amazon.”
The density of the forest, Chism said, often leads to members of the saki groups becoming separated.
• Saki monkeys can live 20 to 30 years in captivity – but often less in the wild.
• If frightened in the wild, sakis will hunker down into the canopy and often sit for hours until they believe the threat has passed.
• And there’s what could be considered kind of a “Where’s Waldo?” factor: The taxonomy of sakis is difficult to determine because the females look similar – no matter their species.
But the males that unexpectedly had reddish-brown fur around their faces caught Chism’s eye.
About the professor
Chism earned her doctorate in biological anthropology from the University of California at Berkeley. She teaches biology and anthropology at Winthrop, in Rock Hill, S.C.,and is the director of graduate studies in biology there.
In 2001, Chism went to South America to work with graduate student Nancy Ward, who was studying uakari monkeys, a threatened species characterized by bright red hair and bald, pink faces.
“I fell in love with the place,” Chism said.
In northeastern Peru, she and Ward spent three weeks trying to find wild uakaris to study – a feat made difficult by local hunting wiping out large species, she said. Chism said hunting is legal in the area but has recently diminished.
The local government set up a communal reserve in the area – the Area de Conservatíon Regional Comunal de Tamshiyacu-Tahuayo – aiming to protect the uakari.
But the communal reserve is open for local residents to take resources they need, and the responsibility to protect the reserve lies with the local population, said Chism, who has worked in the reserve ever since.
In 2003, Ward built a lodge on land she bought next to the reserve. According to Chism, Ward aimed to run the commercial lodge and protect and rescue uakaris.
Chism and other of her students also worked on conservation projects in the reserve. To understand the effect of hunting on the monkey population, they took a census of mammals in both heavily hunted and lightly hunted regions of the area. They found at least 13 species of monkeys, with the larger ones such as the uakari clearly hunted more regularly than the smaller species.
This trend is evident by the lack of spider monkeys that were once spotted in the area.
Their goal, Chism said, was to use this data to show the locals that hunting monkeys is not sustainable.
Facing economic constraints, Ward decided to sell her lodge to Paul Beaver, a biologist with a doctorate from the University of Chicago who had spent many years doing field work in Peru. Beaver turned it into the Tahuayo River Amazon Research Center in 2008.
The research station brings more tourists, which has helped lower hunting in the area, Chism said.
The center’s website invites visitors to become citizen scientists, noting “Primate census of the trail grid was initiated in 2007 and continues to the present time. Students and tourists can choose to assist in the census or in habituation of particular social groups of each of six large-bodied species of monkeys.”
The creation of research trails and the dedicated research facility also makes it possible for Chism and others to complete studies of local species in the dense forest area.
“Large-bodied species” are only part of the primate picture: Twelve species, according to the center’s website, have significant populations on the grid: squirrel monkeys, two species of tamarins, two species of titi monkeys, brown capuchins, white-fronted capuchins, pygmy marmosets, two species of night monkeys ... and two species of saki monkeys.
Those sakis would be the monk and equatorial. But is there an elusive third species?
The answer is along 1,000 acres of tropical rainforest trails, or off the trails in the research center’s 73,313-acre expanse. Just find the female sakis with grayish fur whose masculine partners have reddish-brown fur around their faces.
Chism and a team of grad students will be returning to Peru next June.
Chism said saki monkeys have renewed her interest in vocalization studies as better technology has made it easier to capture and analyze the vocals.
“We have tools we’ve never had before,” she said.
“I’m having fun.”