A new species of monkey has been identified in Peru's remote Amazon rainforest, bringing the number of titi monkeys described by science to 34. The new species, discovered on an expedition to the forests along Urubamba River in 2013, has officially been named Callicebus urubambensis in Primate Conservation. It is different from another locally occurring species, C. brunneus, due to its distinctive coppery coloration.
Titi monkeys are the most numerous group of South American monkeys, and live throughout the Amazon basin. They grow no bigger than a domestic cat, live in what are generally considered monogamous pairs, and are fairly territorial. The adult pairs form close emotional bonds: They coordinate their activities, stay close to each other and frequently huddle together, often while intertwining tails and holding hands.
The discovery of this new species starts with the skin of a small reddish-brown monkey residing in a drawer in the back room of the American Natural History Museum for almost a century. It went unnoticed, forgotten and mislabelled until it caught the eye of a scientist. Already suspecting that there were more than the two species of titi monkey identified in the jungles of southern Peru, lead researcher Jan Vermeer thought that this skin didn’t look much like the animal it was identified as.
And so Vermeer turned to the Internet. “The internet is full of pictures of titi monkeys, often posted by tourists that have been in the jungle and who want to share their experience with the world,” Vermeer explained to Agence France-Presse. While looking at these pictures of titi monkeys, he noticed that some taken in the same region that the mystery skin was collected were also a reddish color. This was all the confirmation he needed to start planning an expedition.
Five years since first finding the skin in the museum, Vermeer and his team were out in the field for a second attempt to try and verify his suspicions. “As soon as we crossed to the western side of the Urubamba River, we almost immediately discovered the new species of titi monkey,” said Vermeer. It’s rare in itself to discover a new species of primate, but what was more surprising was that the new species seems to be doing pretty well for itself, being relatively common in the 350-kilometer-long (217-mile-long) patch of forest. Unfortunately, when many new species are discovered, they're often perilously close to extinction.
The researchers think that its small size might be a blessing: Since it lives in a region with larger primates, the monkey is mostly ignored by hunters. They hope that the discovery will help clarify titi monkey evolution, and considering that only a few decades ago there were only five species of titi monkeys described to science, it’s likely that there are other unknown primate species living in even more remote reaches of the rainforest.
Image in text: The Urabamba brown titi monkey on the banks of the Rio Urubamba. Credit: Jan Vermeers.