White Cheeked Spider Monkey, Ateles marginatus

The White-Cheeked Spider Monkey (Ateles marginatus) is a species of spider monkey, a type of New World monkey that is native to Brazil.

There are many different varieties of spider monkeys that inhabit the upper levels of the rain forest. The White-Cheeked Spider Monkey was placed on the endangered species list after an assessment in 2008 that discovered their population decreased by 50 percent over the course of three generations; this decline can be attributed to loss of habitat and hunting.

This trend is expected to continue because of the increasing expansion of soybean agriculture. Also, parts of their habitat have been destroyed to make way for major highways and extensive deforestation. The White-Cheeked Spider Monkey is commonly found in the Brazilian Amazon. The area it is probably found in resides between the Rio Tapajos and its tributary, the Rio Teles Pires and the Rio Xinu, south of the Rio Amazonas. A part of their territory also lies within national forests such as Tapajos National Forest, Xingu National Forest, Altamira National Forest, Itaituba National Forest, and Itaituba II National Forest.

Some of the native people in Brazil consider the spider monkeys a delicacy, and when this is combined with their low reproduction rate, the population is sure to decline quickly. It usually lives in groups of 20 to 30, but it is rare for them to be seen all together. It is more common for the White-Cheeked Spider Monkey to travel in smaller groups of 2 to 4 when resting and feeding. At around 4 to 5 years old, it apparently reaches sexual maturity and will give birth to one offspring after a gestation period of 226 to 232 days; the interbirth interval can last as long as 28 to 30 months within the wild.

The diet of this spider monkey consists of fruit, leaves, aerial roots, bark, decaying wood, flowers, honey, and even some small insects such as termites and caterpillars. One very important impact it has on its habitat is to offer seed dispersal for different species of plants throughout their territory, it is though that they provide movement for 138 different species of fruit seeds.

Image Caption: Ateles marginatus in São Paulo Zoo. Credit: Miguelrangeljr/Wikipedia (CC BY-SA 3.0)