Primates of the Area de Conservacion Regional Comunal Tamshiyacu Tahuayo.

The Reserve ACRCTT has a greater diversity of species of monkeys than that recorded in any protected park or reserve in the world. We have anywhere from a minimum of 15 species to up to 19 species, described below:

Pygmy Marmoset

The Pygmy Marmoset or dwarf monkey is the world’s smallest monkey with a body length of only 5-6 inches (15 cm ) and a weight of only 4.5 oz (130 gm). Pygmy Marmosets live in groups made up of 1-2 adult males and 1-2 adult females, with a single breeding female and her offspring. The breeding female gives birth to twins twice a year. Pygmy Marmosets are one of the easiest monkeys to find, with at least thirteen families living close to the main Tahuayo Lodge, on trails leading to the canopy ziplines, and on trails behind the canopy ziplines.

Pygmy Marmoset


We have two species of these squirrel-sized monkeys, the Black-fronted Tamarin and Moustached Tamarin. They are both very attractive species and are relatively easy to find running and jumping along tree branches in groups of 5-20 individuals, located on the trail grid at the ARC, and on the trails behind the main lodge.

Moustached Tamarin

Titi Monkeys

The Coppery Titi Monkey lives in family groups of male, female and 2-3 young. At the crack of dawn the male and female call to each other in a loud staccato duet. From the ARC we typically hear several families every morning just before dawn. We commonly find titi monkeys on the trail grid behind the ARC and sometimes along the Tahuayo River on motorboat excursions. We believe that in addition to the familiar Coppery Titi Monkey we may also have another species of titi monkey unknown to science.

Coppery Titi Monkey
Coppery Titi Monkey

Squirrel Monkeys

The Common Squirrel Monkey (Saimiri sciureus) is commonly seen by motorboat excursions along the Tahuayo River near the main lodge, especially around Lake Charo, as well as the ARC. Common Squirrel Monkeys are easily spotted because they live in large groups, of up to 100 individuals. We may have an undescribed species of squirrel monkey in the ACRCTT. While the Common Squirrel Monkey is a gracile species that live in troops of up to 100 individuals, the other species have a larger, more robust morphology, more golden brown coloration and lives in smaller groups, rarely over 20 individuals.


Saki Monkeys

In addition to the Monk Saki the ACRCTT has another species of saki monkey not known in the scientific literature. Unlike other saki monkeys, this species has a balder face, sexual dimorphism, and other unique features. It has been the subject of an investigation by Dr. Janice Chism for several years. Dr. Chism presented a paper about this new species to the International Primatological Society meeting in Mexico City, August 2012. This exciting, rare species can frequently be found on the trail grid behind the ARC.

Saki Monkey


Both White-fronted Capuchin and Large-headed Capuchin are found in the ACRCTT. Capuchins have the largest brain size relative to body size and are considered to be the most intelligent of the New World monkeys. They have a complex social organization consisting of 15-40 individuals. We often see both species of capuchins on the trail grid behind the ARC as well as on motorboat excursions near the ARC.

White-fronted Capuchin

Howler Monkey

The calls of the Red Howler Monkey are among the loudest in the world. These monkeys are not easy to find. Only during certain months of the year (August-November is best) can we locate on the trail to Lake Yarina Nueva (near the ARC) and on the trails walking for some distance behind the main lodge.


Uakari Monkey

The ACRCTT and buffer zone by the Yavari River is the only home of the rare Bald Red Uakari Monkey. This very rare species lives in groups of 40-60 individuals. We can sometimes find them on the trail grid behind the ARC when the Mauritia palm fruits are ripe, June-September, and at other times in the terra firme forest (camping) behind the ARC or near the headwaters of the Tangarana River, a tributary of the Tahuayo River upstream from the Research Center Lodge.

Red Uakari Monkey
Red Uakari Monkey

Woolly Monkey

We have the Poeppig´s Woolly Monkey in the reserve. Woolly Monkeys are often viewed on hikes to Lake Yarina (from the Research Center) and in the terra firme forest behind the Research Center.

Woolly Monkey

Owl Monkeys

Owl monkeys or night monkeys are the world’s only nocturnal monkey. It is not known how many species of owl monkeys live in the ACRCTT. We know that we have Aotus nancymae, possibly Aotus nigriceps and maybe even a third species. These very attractive monkeys are sometimes seen sleeping in tree cavities close to the main lodge and often pose in the late afternoon for photos.

Owl Monkeys

The Black Spider Monkey is known to live in the interior of the ACRCTT. We do not typically see them near either lodge.