Spider monkeys are endangered mainly due to habitat loss and hunting. Their slow reproductive rate also makes them vulnerable, as a female spider monkey only has one baby every two to four years.
Spider monkey habitat loss occurs due to logging of forests as well as clearing for land use such as slash-and-burn agriculture, cattle ranching and commercial farming for crops such as coffee, cocoa and soy. Timber plantations replace indigenous forests. Mining of bauxite, clay, granite and sand causes deforestation, erosion and the pollution of fresh water supplies. Illegal palm harvesting decimates entire stands of palm trees. Highways, farmlands and urban areas interrupt habitats, and because they prefer old growth and avoid disturbed areas, spider monkeys do not respond well to habitat fragmentation. In some areas, spider monkeys are hunted for sport and for food. They are also captured for pet trafficking.
As of 2014, efforts to protect spider monkeys include research about the size and status of current populations, the effectiveness of protected areas and the extent of poaching. A number of national parks, state parks and environmental protection areas are established in South American countries such as Brazil, Columbia, Ecuador, Peru and Venezuela. However, in some areas, the presence of political insurgents and the military as well as the lack of park rangers makes enforcement problematic.