Generales

Medellín's gray titi monkey is the only species of urban monkeys found in Colombia.  Researchers at Universidad de Antioquia named it "titi paisa" after the people native to the city of Medellín, Colombia.

Picture: one of the four gray marmosets that inhabit the campus

While Europeans and Americans often spend large amounts of money on trips to Africa to see wild animals in their natural habitat, Medellín residents don't have to go far to see funny titi monkeys scampering through the roofs of the UdeA campus and making mischief at the faculty offices.

Medellín is home to the gray titi monkey, a small primate with gray-brown-white fur found only in the Colombian departments of Antioquia, Bolívar and Tolima.

Also known as white-footed tamarin, gray titi monkeys have an extraordinary adaptability that allows them to live in a variety of environments.

Gray marmosets inhabit Medellín long before 1616, the city's official founding year, despite the fact that numerous highways, buildings and factories have been erected close to their natural habitat.

This is also the only species of urban monkeys found in Colombia (and possibly one of the few species of urban monkeys worldwide). 

In an article entitled Physiological and parasitological implications of living in a city: the case of the white-footed tamarin (Saguinus leucopus), which was recently published in the American Journal of Primatology, five UdeA researchers compare the living conditions of Medellín’s gray titi monkeys with those of marmosets that inhabit Colombian rainforests.

According to the article, Medellín’s marmosets typically gather in groups of 4 to 10 members distributed at altitudes ranging from 1,400 to 1,692 MASL. The groups inhabit forests adjacent to residential neighborhoods in the hills of western Medellín (about 30 individuals) and in the UdeA campus (2 males and 2 females).  

Like their human cousins, monkeys are very social animals. However, Medellin’s Botanical Garden is home to a solitary marmoset which is believed may have escaped from being kept in a private home, says biologist Ivan Soto, coauthor of the article.

Picture: a student plays with marmoset at the UdeA campus

They need to lose weight

The researchers found that marmosets that inhabit urban areas are more obese than those living in the wild due to reduced physical activity and the large amount of food sources available in urban environments.  

“There are lots of fruit trees throughout the city so monkeys always have food available, which is a factor that makes them go obese due to lack of physical activity,” Professor Soto said.

In addition, titi monkeys are friendly animals so people often feed them, and much of the food they receive is not good for them. “Some people think that giving bananas to the monkeys is good for them, but bananas are very high in sugar which can help increase the risk of obesity. Even some people give candy to the monkeys that inhabit the campus,” the researcher said.

These monkeys are so used to eating sweets that they have learned to open sugar sachets they find on tables and corridors across the campus.

But marmosets also become overweight because of the lack of space to maneuver. The titi monkeys that live in the University facilities never leave the campus grounds, and those that inhabit the western hills of the city face the threat of being hit by cars or being electrocuted by power lines.

Another factor threatening the survival of these animals lies in the fact that the groups are isolated from each other which results in consanguineous relationships, so the offspring may be at increased risk for genetic disorders.

Picture: one of the titi monkeys that live in the hills of Medellín

Territorial disputes  

However, isolation is somehow beneficial for marmosets since it reduces the likelihood of territorial disputes because these animals are highly territorial and will challenge any intruders within their home range.

“A surprising fact about this species is that they form female-dominated hierarchies in which females decide when and with whom to mate. The dominant female has the ability to inhibit fertility in the other females but once the babies are born the other monkeys will help the mother to take care of the newborns,” Professor Soto said. 

Another difference between urban marmosets and those that live in the wild is that the former are cleaner and have fewer parasites. Although this is an important factor for reducing mortality, urban titi monkeys live in a hostile environment fraught with risks and dangers.

In danger of extinction

White-footed tamarin is included in several lists of endangered species including the IUCN Red List of Threatened Species, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and Libro Rojo de los Mamíferos de Colombia. 

Although some biologists have suggested to release the communities of urban marmosets back into their natural habitats, others like Professor Soto say these monkeys are already part of the biodiversity of Medellín, and therefore, efforts should be made to improve their quality of life rather than transferring them to other environments.   

Initiatives to improve the quality of life of urban marmosets include the construction of bridges or ecoducts to allow animals to safely cross highways; campaigns aimed at better understanding the behavior of titi monkeys and how to properly feed them; and raising public awareness about the importance of these animals.

“Although Medellin is the first city in Colombia to have a biodiversity policy, initiatives often remain on paper. It is imperative to design policies aimed at making a truly sustainable city," Professor Soto said. 

Medellin is also home to 2,603 plant species, 1,764 insect species, 445 birds, 91 mammals, 44 reptiles, 30 amphibians, and 44 fish species.