Last year I spent three weeks with an incredible team of scientists exploring the Tapiche-Blanco watersheds, a remote region in the Peruvian Amazon. Our team was about 200 kilometers from any of the nearest cities--Iquitos, Pucallpa, and Tarapoto--and 40 kilometers from the border with Brazil.
The trip was filled with discoveries (three new plants, four new fishes, four new frogs, a savanna habitat none of us expected in this part of Peru) but the biggest discovery was a mystery monkey.
One of our ornithologists, Brian O'Shea from the North Carolina Museum of Natural Sciences, saw three pale orange Callicebus monkeys. He was able to photograph one of them (check out the baby on its back!). None of us have ever seen this color variant before, and collectively our group has been all over the Western and Eastern Amazon in the last 20-40 years.
At the same campsite we found Callicebus cupreus, the Coppery Titi Monkey, a species we expected to find here and that we have seen before. You can see the coloration is quite different, especially on the face and body, with much darker tones than our mystery monkey. We found Callicebus cupreus in the gallery forests growing along the rivers and streams in the area, and we found the mystery Callicebus in the tall upland forests.
As soon as we left the field, we wrote or talked to every Callicebus or South American mammal expert we knew--Rolando Aquino, Victor Pacheco, and Jan Vermeer in Peru; Thomas Defler in Colombia; Paulo Auricchio in Brazil; Robert Voss and Paul Velazco at the American Museum of Natural History; Bruce Patterson from The Field Museum--and none of them had ever seen this color variant before! Every single one of them stressed that Callicebus is incredibly variable and that the taxonomy could use additional work. Without a specimen, without DNA, it is impossible to know whether this is a new Callicebus species.
When we returned to The Field Museum we went to our collection of South American primates, with incredible specimens from Phillip Hershkovitz, illustrious former Mammals Curator at the Museum; Peruvian naturalist Celestino Kalinowski; and the Ecuadorian brothers Alfonso and Ramón Olalla; among others. We looked through all of the Callicebus skins in the Museum--over 80 specimens--and did not find a single match for the colors we saw on our mystery Callicebus in Peru.
Finding a new color morph--or a new species--of primate is rare anywhere in the world. Our mammalogist, Mario Escobedo, is looking for funding and permits to return to the area and collect DNA data (through feces or specimens or both). We welcome information from anyone on similar coloration of Callicebus elsewhere in Peru or South America.
Finally, I want to highlight that these trips invariably turn up new species--anywhere from 10-50 new species per expedition--and that the Age of Discovery is far from over. At the Field Museum of Natural History, scientists described 174 species in 2014 alone, and 1,313 species in the last 15 years. The head of our Collections Center, Bill Stanley, describes museum discoveries as constantly redefining the "edges" of life on Earth.
Learn more about our rapid inventories
Follow our expedition on Facebook to stay up to date on the latest news: RI27: Tapiche-Blanco
Read a press release about the Tapiche-Blanco inventory
Review the revised taxonomy of Callicebus from Paulo Auricchio, Neotropical Primates, 2010