Brown spider monkeys are social monkeys known for having a prehensile tail that acts as a fifth limb. They live in social mixed gender groups of 3-22 that split into smaller groups for foraging, where they primarily search for ripe fruit. They are critically endangered and are one of the worlds most endangered primates, due to being hunted for food and habitat loss. Many populations do not occur in protected areas, making their conservation hard to manage. Due to their slow reproductive rate, they repopulate slowly.