Plecturocebus caquetensis

Geographic Distribution and Habitat

Discovered by a scientific expedition to the Colombian Amazon in 2008, the Caquetá titi lives deep in the hot and humid rainforests of the Caquetá region of Colombia, close to the border of Ecuador and Peru. The species’ range encompasses an area of about 39 mi² (100 km²) and includes dense, low forests of small, thin, broadleaved trees and bushes of no more than 33 to 49 ft (10 to 15 m) in height and between 623 to 853 ft (190 to 260 m) above sea level, surrounded by swampy pastureland.

Although a wildlife behaviorist caught a glimpse of this monkey 30 years prior, decades of civil unrest in the area followed and prevented repeat visits to confirm the existence of this unique species. So the discovery of 13 family groups of Caquetá titi monkeys, along the upper Caquetá River, gave scientists reason to celebrate. And worry. Severe habitat loss in the region has relegated the monkeys to a tiny fraction, about 3.9 mi² (10 km²), inside their geographic range. This habitat degradation, coupled with a small population—less than 250 adult individuals are believed to exist— is threatening this rare species’ existence, just as the world is coming to know this enigmatic primate.

Caqueta titi range, circled in red, IUCN 2022

Size, Weight, and Lifespan

The Caquetá titi monkey is about the size of a domestic house cat and has a long tail like most house cats. Specific height and weight measurements are not yet documented for this little-studied, new species. However, wildlife biologists have established that the various species of titi monkeys (estimated at 20, all who live in the Amazon basin) vary significantly in size, although they share other physical attributes. Generally speaking, head-to-body length in female titi monkeys is 11.5 to 16.5 inches (29 to 42 cm), with a weight between 1.5 and 2.25 pounds (700 to 1,020 gm). Tail length is between 14 and 25 inches (36 to 64 cm). Head-to-body length in male titi monkeys is 12 to 18 inches (30 to 45 cm), with a weight between 2 and 3 pounds (800 to 1,200 gm). Tail length is between 15 and 20 inches (39 to 50 cm).

Lifespan for the Caquetá titi monkey is unknown.


“A species of titi monkey that purrs like a cat and looks like a leprechaun” is how one smitten online news publication heralded the debut of this tiny New World primate.

In fact, the Caquetá titi monkey shares a few similarities with the fanciful leprechaun of Irish folklore: both are wee-size and elusive, and both sport a red beard. (And yes, the Caquetá titi monkey purrs like a cat! More on that in a bit.)

Like some other species of titi monkeys, the petite but stocky bodies of Caquetá titi monkeys are cloaked in thick, soft, long fur coats that are brownish or reddish in color and may be tinged with black. Their undersides are a burnt orange or chestnut color, and the crowns of their rounded heads are speckled with orange, black, or light brown hairs. Bushy red beards frame their little alien faces (drawing the leprechaun comparison!). Their thick and furry long tails are a mottled gray.

Unlike other closely-related titi monkey species, whose foreheads are marked with a white bar, the foreheads of Caquetá titi monkeys sport grayish hairs. Caquetá titi monkeys also lack the white hands and feet of other titi monkey species.

Belying their diminutive build, Caquetá titi monkeys are sturdy and strong.

Photo credit: Javier Garcia/Estación Ecológica Omé. Used with permission.

Caquetá titi monkeys are mostly fruit-eaters; however, they will also eat flowers, leaves, seeds, and the occasional worm or insect.

Behavior and Lifestyle

Because of the species’ rarity and rather recent discovery, not a lot is known (or documented) about the Caquetá titi monkey. This dearth of information has led wildlife biologists to make conclusions, or conjectures, by drawing comparisons and contrasts to other species of titi monkeys.

A mostly arboreal species (that is, spending much of the time in trees), Caquetá titi monkeys deftly climb through the rainforest canopy on all fours, using their non-prehensile tail to balance. Their powerful rear limbs enable them to leap spectacular distances between trees while they grasp onto branches with their hands.

When resting, titi monkeys sit in a hunched posture, with all four limbs tucked and their hands folded. They allow their tails to hang vertically from the tree branch upon which they are perched. At bedtime, titi monkeys sleep huddled together in carefully selected trees that offer protection from predators.

Fun Facts

Titi monkeys are called zogui zogui in Spanish.

Dr. Thomas Defler, Marta Bueno, and their student, Javier García from the National University of Colombia are credited with discovering the Caquetá titi monkey in 2008. Their discovery confirms the initial sighting of the species, in 1969, by wildlife biologist Martin Moynihan.

The intrepid trio began their field study at the village of Valparaíso, Caquetá, where Moynihan first observed the monkeys. They then traveled to the upper Caquetá River, navigating with a GPS and searching for the monkeys on foot and by listening for their calls. Garcia, a native of Caqueta, used his status as a local to gain the trust and secure permission from local landowners and farmers to visit the small patches of forest where the Caquetá titi monkeys reside.

Daily Life and Group Dynamics

The group’s adult male leads the foraging activities, communicating to others in the group through various vocal and visual signals to announce food sources. The group feeds during the early morning and again in the late afternoon.

As with other titi monkeys, wildlife biologists hypothesize that Caquetá titi monkeys are territorial in nature. Acting as aggressor, the adult titi male will defend his family group from other titi monkeys by using rapid and loud threatening vocalizations and occasionally giving chase to an intruder.


The Caquetá titi monkey is not only comparable in size to a domestic house cat; this tiny monkey purrs like a cat, too! Babies, especially, are known to purr when they are feeling content.

Caquetá titi monkeys use different vocalizations for foraging and for marking territory. Territorial vocalizations are complex calls that are given each morning, reminding would-be intruders to stay away.

Reproduction and Family

Like other titi monkey species, Caquetá titi monkeys are led by a pair of monogamous adults who form a life-long relationship with one another. Grooming is a daily activity between the bonded pair, who often sit side-by-side on a shared perch in the trees, holding hands and with their tails intertwined.

Monogamy is a big deal in the primate world because it doesn’t happen often. The Caquetá titi monkey joins the gibbon, the owl monkey (also known as a night monkey), and the golden lion tamarin in this noble distinction. But the practice might be less about true love and more about survival. Monogamy lessens the risk of infanticide; parents who are bonded to one another decrease the chance of an outside rival male entering the troop and killing the babies in an effort to steal the affections, and breeding privileges, of the female from her male partner.

An adult female gives birth to a single infant after a gestation period of five to six months. Except for nursing her baby, the mother passes off child-care duties to her male partner. He carries the infant and entertains his progeny with play. Older offspring allow their parents the time and space to focus on their new baby brother or sister. That is, they practice not being pains in their parents’ butt.

The age that the young are considered weaned is not documented. However, juveniles remain with their family group until they reach maturity, usually in their second year, when they leave home in search of their own mate.

Of the 13 family groups of Caquetá titi monkeys discovered during the 2008 Amazon expedition, wildlife biologists observed a single adult male, a single adult female, and their offspring; average group size was four individuals. Small and cohesive family groups are consistent with other titi monkey species.

Photo credit: Javier Garcia/ Estación Ecológica Omé. Used with permission.
Ecological Role

Thanks to their largely frugivorous diet, Caquetá titi monkeys help to regenerate their forest habitat by dispersing seeds via their feces, thereby encouraging new plant growth.

Conservation Status and Threats

With a fragmented population of no more than 250 adults, the Caquetá titi monkey is classified as Critically Endangered by the International Union for Conservation of Nature (IUCN, 2011), appearing on the IUCN Red List of Threatened Species. This highest threat level means that the species faces an extremely high risk of extinction in the wild. The population experienced a reduction of 80 percent between 2000 and 2010.

The Caquetá titi monkey was named among the World’s 25 Most Endangered Primates, 2016-2018 in the Primates in Peril publication produced by the IUCN SSC Primate Specialist Group (PSG) et al in 2017.

According to the IUCN, a healthy population should be in the thousands. Habitat destruction—land cleared for agricultural use, including illicit crop growth (for drug cultivation) and widespread ranching—is to blame for the low number of Caquetá titi monkeys. Pollution and environmental poisoning through herbicides and pesticides are additional risk factors. The monkeys are also hunted for food.

Because their natural habitat is fragmented, Caquetá titi monkeys are forced to live as isolated groups, confined to certain areas by barbed wire and a barren savanna that has been grazed by cattle. If this severe habitat degradation continues, says the IUCN, the Caquetá titi monkey population will plummet another 80 percent, or more, in a 24-year span. And this tiny bearded primate, who purrs like a cat and who some say looks like a leprechaun, may eventually be forever lost from the world.

Conservation Efforts

Unfortunately, no populations of Caquetá titi monkeys have been found in protected areas. And violent outbreaks between warring factions throughout the Caquetá titi monkeys’ range make travel and field study there dangerous.

To ensure the continued existence of the Caquetá titi monkey, the environmental protection group Conservation International is urging world leaders, particularly the Colombian and Caquetá governments, to create protected habitat areas (reserves), implement initiatives that provide economic incentives to impoverished local communities, and create local environmental education programs. But at present (October 2016), the future of the Caquetá titi monkey remains in grave peril.

our thanks

Many thanks to the generosity of ​Dr. Thomas Defler and his team at Estación Ecológica Omé for providing these beautiful photos of the Caquetá titi monkey and allowing us to share them with you.



Written by Kathleen Downey, October 2016