Brown Spider Monkey, Ateles hybridus

Brown Spider Monkeys have long and thin limbs with their forelimbs being longer than their hind limbs. They also have a distinctive 75 centimeter long flexible and thin prehensile tail which at times acts like a fifth limb. The tip is hairless with ridged skin for better grip. All of these features of their body make it possible for them to climb trees and high elevations, hang and swing from one tree to another without having to lower themselves to the ground frequently. Their hands are slightly curved looking with smaller thumbs. The adult males weigh between 7.9 and 9.1 kilograms and the adult females weigh between 7.5 and 9 kilograms. Their average adult body length is roughly 50 centimeters. Their coloration ranges from light brown to dark on the upper parts including the head. Their most distinctive trait is their white triangular forehead patch all though not all spider monkeys have this. Some, even though very rare, possess pale blue colored eyes.

The average lifespan of a spider monkey Is 27 years, however, while in captivity, that can be increased by 10 or more years.

This Brown Spider Monkey is among “The World’s 25 Most Endangered Primates”, and is one of only two Neotropical primates to have been included in this list in both 2006-2008 and 2008-2010. They were recognized as species only 10 years ago. Forest fragmentation, hunting, and loss of habitat are the major threats for the remaining monkeys.

In Columbia, they can be found from the right bank of the Rio Magdalena in the Departments of Magdalena, Cesar.

They are normally found in elevations between 20 and 700 meters. Though they spend the majority of their time in high elevations to move about, they sometimes descend to eat soil and to drink water. Since they like trees and foraging in high canopies, they show a preference for forests that haven’t been disturbed, known also as primary forests. This is due to primary forests offering lifestyle that they are comfortable in. They always travel in small groups, and rather than walking or running on all fours, they travel mainly by swinging and climbing between trees.

They mainly forage in the canopies of the forests and rely mainly on their senses of light, taste, smell, and touch to find their food. The Brown Spider Monkeys are mostly herbivores and frugivores. A main component of their diet is ripe fruit. 83 percent of their diet is lipid rich fruits. However, in dryer seasons where the fruit is less plentiful, the monkeys feed on seeds, leaves, flowers, honey, bark, decaying wood, and sometimes insects such as termites and caterpillars. They feed on different species of figs all year round. Scientists have observed them eating soil and clay, and hypothesized that the reasons for this behavior could be to acquire minerals from the soil, for phosphorus, or in order to maintain pH-balance in their digestive system. They find water to drink on the forest floor at “salado sites”. Competition for food takes place between the spider monkeys and other frugivorous primates.

Their largest threats are jaguars, mountain lions, harpy eagles, and crested eagles. They are known to shake branches in order to ward off potential predators. They are also targeted by humans as a favorite game species, particularly in Columbia to be sold as pets in which case the mother is killed and her baby is sold into the pet trade.

Image Caption: A critically endangered Brown Spider Monkey, Ateles hybridus, with uncommon blue eyes. Shot in captivity in Barquisimeto, Venezuela. Credit: Fir0002/Wikipedia (CC BY-SA 3.0)