Geographic Distribution and Habitat
The Caquetá titi (Plecturocebus caquetensis), also known as the red-bearded or bushy-bearded titi, was first spotted by a scientist in 1969, although, because of armed conflict issues, it was unable to be properly recognized as a species until 2010. Sadly, by the time Caquetá titis were recognized by science, they were already critically endangered. Caquetá titis are endemic to a very small geographic range in Colombia, only about 39 mi² (100 km²). They are believed to be restricted between two rivers—the Orteguaza and the Caquetá—near the base of the Andes Mountains, although future fieldwork may show that their range is slightly larger than this. They usually live on the edges of seasonally flooded bamboo forests. However, their habitat is so fragmented and disturbed that it is not clear what their natural, original habitat preference is: tropical forest, tangled vegetation near water, or something else? Unfortunately, it’s unlikely that we’ll ever know. Because Caquetá titis have only recently been described, and because conflict issues in their range can make them difficult to study in the field, there are many other unanswered questions about this monkey. However, other titi species share quite a few similarities, so this profile fills in some gaps about the basic biology of the Caquetá titi using closely related species.
Historically, titis were believed to all belong to the same genus, Callicebus. It wasn’t until 2016 that a three-genera model was proposed, splitting the genus into Cheracebus, Callicebus, and Plecturocebus, where Caquetá titis are placed. Their closest relatives are the ornate titis (P. ornatus) and the white-tailed titis (P. discolor). There are 21 other species in this genus according to this model, and more than 30 titi species altogether. The fact that there are so many explains why new titis have been discovered even in the last 15 years, and there may well be undiscovered species.
Size, Weight, and Lifespan
Caquetá titis are on the small side for primates, about the size of a rabbit. While exact measurements are not available for Caquetá titis, approximations can be made based on closely related species. They likely weigh about 28 oz (0.8 kg) on average, while their head and body is about 12–13 inches (31–34 cm) long. Their tails add another 14–25 inches (36–64 cm) on average. Titis have been known to live for more than 25 years in captivity.
Caquetá titis are small monkeys, but make no mistake—they are sturdy and strong. Their backs and tails are a range of hues from brown to gray. Their large eyes and long rusty red beards give them the appearance of a leprechaun. The striking red beard leads down their underside and inner arms all the way to their feet, almost as if each monkey has found themself clinging to a freshly painted red wall at some point in the past! Titis display no sexual dimorphism, meaning that males and females look the same besides the obvious anatomical differences.
Caquetá titis are mostly herbivorous, although their diet is supplemented with the occasional bug or two. One year-long study found a dietary breakdown of Caquetá titis as follows: 36% fruit, 27% young leaves, 21% seeds, 7% flowers, 4% mature leaves, 3% insects, and 1% stems, based on the time spent eating. Their most commonly eaten plant is one from the nettle family, called Pourouma bicolor.
Behavior and Lifestyle
Like all titis, and indeed most Latin American monkeys, Caquetá titis are diurnal, meaning that, like humans, they are awake during the day. Also like some humans, Caquetá titis often take a midday nap to keep their energy up. Caquetá titis move about on all fours, using their long tail to help balance in the trees, where they spend most of their time. Each titi family sleeps in a tree at night, and they usually return to the same tree night after night. As small primates, Caquetá titis are at risk from predators such as eagles and boas, and they mainly rely on hiding to avoid these animals. Typically, Caquetá titis spend 40% of their time on an average day foraging and eating, 40% resting, 16% traveling, and 4% performing social behaviors.
Male Caquetá titis are devoted fathers, spending many hours carrying their babies, who are known to purr when content.
Dr. Thomas Defler, Marta Bueno, and their student, Javier García, from the National University of Colombia, are credited with discovering the Caquetá titi in 2008. Their discovery confirms the initial sighting of the species, in 1969, by wildlife biologist Martin Moynihan. The 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 Caquetá, 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 titis reside.
Caquetá titis live in small family groups, consisting of an adult female, adult male, and up to four offspring. The adults are known to be very affectionate with one another, often encouraging closeness. Caquetá titis, like other titis, are believed to be highly territorial, carefully protecting their home range from other monkeys using loud vocalizations and giving chase when needed.
Titis are known to be more vocal than most other Latin American primates, and their vocalizations are often more complex. Family members communicate and bond through touch, grooming each other during their midday rest, and the adults often intertwine their tails together while sleeping and even simply when sitting next to each other. Baby Caquetá titis are known to purr when they are content.
Caquetá titis are monogamous, meaning that they typically have just one mate for life, or close to it. Social monogamy—living together and raising young with the same partner—is quite rare in the primate world, although not unheard of. However, titis take this a step further. Not only are they socially monogamous, they are believed to also be sexually monogamous—meaning that they only mate with that partner, never being “unfaithful,” as a human would put it. One genetic study of the closely related coppery titi (P. cupreus) found that in an entire population, there was not one case of “infidelity”—or, more scientifically, of an offspring fathered by any male other than their mother’s partner. This is extremely rare, not only for the primate world, but for the animal world at large.
Little else is known about the reproductive lives of Caquetá titis specifically, but most titis share similar patterns. Each pair of titis has, on average, one baby per year. Their gestation period is about five and a half months, and babies are most often born between December and April. Fathers play a significant role in baby rearing—in fact, infants spend most of their time being carried by their fathers until it’s time to nurse. It takes about ten months for a baby titi to reach their full adult size, and it’s another five months before they get all of their adult teeth. The offspring stay with their parents until they are about two to three years old, at which point it’s time for them to leave their group and find mates of their own.
As fruit-eaters, Caquetá titis are likely important seed dispersers, as they pass the seeds from the fruit they eat and distribute them over the landscape. Titis are often preyed upon by predatory birds, such as hawks and eagles. Snakes and felines may also prey upon Caquetá titis, particularly infants.
The International Union for Conservation of Nature lists the Caquetá titi as Critically Endangered (IUCN, 2021), appearing on the IUCN’s Red List of Threatened Species. They are suspected to have undergone an 80% loss in population over the last 24 years, or about three generations. Surveys conducted between 2008 and 2010 found only 82 individuals, and a survey in 2022 found slightly more, 129 individuals, although this is still a catastrophically low number.
The devastating population decline of Caquetá titis is due to a number of factors. Extensive deforestation for agriculture has continued for decades, as has the spraying of plant-killing contaminants by the Colombian government in an effort to stop cocaine production. However, these contaminants, called defoliants, work by causing leaves to drop from plants, and they work indiscriminately. Not only do the defoliants kill the targeted cocoa plants, they also kill virtually any plant they contaminate. It does not take an experienced ecologist to understand the devastation that can occur across a landscape from such a harmful and indiscriminate substance.
Furthermore, extensive habitat degradation and fragmentation has only worsened the plight of Caquetá titis. Many individuals are trapped in small forest fragments that are separated by grassy savannah or even barbed wire fence—obstacles that are highly dangerous or even impossible for the forest-dependent animals to cross. Thus, they are stuck in their tiny fragments of degraded habitat. Compounding all of these issues is the risk that climate change poses to Caquetá titis. Climate change is expected to have significant impacts in Colombia, primarily in the form of rising temperatures and extreme rainfall that will cause rapid ecosystem degradation, floods, and landslides. Climate change is also expected to heavily impact Colombia’s agriculture industry, possibly leading to more habitat loss for Caquetá titis as more land is used to grow crops.
Caquetá titis are listed in Appendix II of the Convention on International Trade in Endangered Species (CITES), an international agreement between governments whose goal is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. Caquetá titis have not been found in any protected areas, and social factors in this area can make it dangerous for researchers and conservationists to work in the field. However, some scientists have been successful in gathering data with the help of local people.
One local conservation group, Piamonte Biodiverso, is currently working on a project to promote the conservation of Caquetá titis. The priorities for this project are education of the local people, creation of conservation strategies through community meetings and workshops, and training interested locals in primate recognition, which can help to promote sustainable livelihoods like ecotourism in the area.
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.
- Acero Murcia, A., A. Vaquiro, L. Jhoana, J. Garcia, T. Defler, R. López Camacho. 2018. Diet of the Caquetá Titi (Plecturocebus caquetensis) in a Disturbed Forest Fragment in Caquetá, Colombia. Primate Conservation. 32.
- Defler, R., M. Bueno, J. Garcia. 2010. Callicebus caquetensis: A New and Critically Endangered Titi from Southern Caquetá, Colombia. Primate Conservation 25:1-9. https://doi.org/10.1896/052.025.0101
- Dolotovskaya, S., C. Roos, E. Heymann. 2020. Genetic monogamy and mate choice in a pair-living primate. Sci Rep 10, 20328. https://doi.org/10.1038/s41598-020-77132-9
- Villota, J., G. Delgado-Bermeo, A. Ruiz, J.García-Villalba, H. Ramírez-Chaves. 2022. Distribution update and natural history of Plecturocebus caquetensis (Mammalia: Pitheciidae) in Colombia. Biota Colombiana 23(1). https://doi.org/10.21068/2539200X.1007
Written by K. Clare Quinan, January 2023