Neotropics (New World) Most Endangered Primates 2014--2016 | Spider Monkey Conservation Project, Ateles hybridus, Caparo Forestry Reserve, Venezuela  Brown spider monkey Ateles hybridus is of particular interest for conservation. It is distributed in both Colombia and Venezuela, and considered Crtically Endangered due to habitat destruction. The spider monkey is included in the IUCN&#x27;s 25 most endangered primate list.