Five species of acrobatic monkey that have long flown under the scientific radar have been named in South America.
These “flying monkeys,” or sakis, are notoriously shy and hard to study in their vast Amazon rain forest homes, where they’re known to sail quickly from treetop to treetop.A male white-faced saki, the most common saki species, is pictured in a captive setting in the Netherlands in 2008. Part of Marsh’s work included studying white-faced sakis and their relationships to other sakis. Photograph by Russell A. Mittermeier
Scientists had previously identified five species of the 8-pound (4-kilogram) primates, known for their colorful facial hair and bushy coats that they puff out when threatened. (Also see “Pictures: Bushy-Bearded Titi Monkey Discovered.”)
But after nearly ten years of analyzing saki museum specimens, photographs, and animals in the field, behavioral ecologist Laura Marsh and colleagues have finally cracked the code of the Pithecia genus, which is now expanding to 16 species, including 5 new to science.
The newbies include Cazuza’s saki, Mittermeier’s Tapajós saki, Rylands’ bald-faced saki, Pissinatti’s bald-faced saki, and Isabel’s saki, according to the study in the July issue of the journal Neotropical Primates, which is published by the IUCN/SSC Primate Specialist Group and Conservation International.
Three of the newly named species were previously thought to be subspecies, while another three were thought to be variants of known species.
Marsh, director and cofounder of the Global Conservation Institute in Santa Fe, New Mexico, first became intrigued with saki monkeys—which resemble “fluffy, kinda uglyish cats that run on the tops of trees”—about a decade ago in Ecuador.
The scientist quickly realized that some of the animals she saw weren’t in her field guide—and her curiosity eventually took her to museums in 17 countries, where she examined more than 800 skins and 690 skulls. She also studied hundreds of high-resolution photographs of the primates before reworking the saki family tree. (Also see “New Snub-Nosed Monkey Discovered, Eaten.”)
Part of the challenge in deciphering sakis is the remarkable diversity in color and shape within a single species: A juvenile male has similar coloration to an adult female, for instance. What’s more, some females have protruding clitorises, so in museum specimens “it looks like a penis,” Marsh said.
And flying monkeys are stealthy: “They vocalize in grunts, chirps, whistles, and low calls, but can be exceptionally quiet when sneaking away from a perceived threat such as a field researcher,” Marsh wrote in the study.
Marilyn Norconk, a professor at Kent State University in Ohio who studies sakis in Guyana, said the new research is the first comprehensive study of these elusive seed-eaters since the 1980s. (See National Geographic’s photo gallery of other monkeys.)
“I’d been expecting this for some time,” said Norconk, who wasn’t involved in the new research. “[The study is] providing the framework with a lot of new species names and some geographic localities.”
But there’s plenty more to learn. Marsh didn’t do genetic analyses of sakis, for instance, and “in terms of biology and behavior of this group, we still don’t know a whole lot,” said Norconk.
The next step will be more expeditions to investigate the newly named sakis’ populations—and vulnerability to extinction.
Norconk noted that in Guyana, the white-faced saki seem to adapt well to habitats that have been affected by humans, and its populations are thriving.
For this species, which is more well studied, “I think they’re a good-news species—let’s understand more about them and why they’re doing so well, even in areas that are disturbed.”
But the status of sakis in other parts of their South American range is unknown. For instance, with parts of the Amazon “completely chewed up” by agriculture and development, Marsh suspects that the habitats of some of the flying monkeys may be dwindling. (Read “Last of the Amazon” in National Geographic magazine.)
That’s why her study is so crucial: “If we can’t name it, we can’t save it. If we’re calling everyone one species and it’s really ten different things, you have just lost part of the biodiversity on Earth,” she said.
“I feel like we got the road map—now it’s time to get to work.”