In the Amazon forests of Brazil, Bolivia and Peru, the black spider monkey (Ateles chamek) has been one of the species of monkey most affected by the habitat destruction, fragmentation or alteration caused by the growing presence of humans, and it has been classified as endangered since 2014 by the International Union for the Conservation of Nature (IUCN). Other threats to this species include hunting and the illegal trade in animals destined to be sold as pets.
Known in the Amazon forests of southeastern Peru by its Quechua name “maquisapa” (maqui = hand, sapa = large), the spider monkey is a key component of the ecosystems it inhabits, influencing the composition and function of these areas of forest and contributing to regeneration through its feeding habits and territorial range, which combine to make it an efficient disperser of the seeds of several Amazon tree species.
Also known as the Peruvian spider monkey, this is a fairly large primate, with a body length of up to 60 centimeters (two feet) and a one meter long tail (three feet). Helped by the fact that it only possesses a vestigial thumb, it is able to travel through the forest canopy by swinging from one branch to another, using only its arms. This adaptation makes the spider monkey the most agile of the many monkey species that inhabit Tambopata National Reserve. It can be spotted feeding during the day in the high forest canopy.
Although Peruvian spider monkeys tend to live in groups of up to thirty-five individuals, it is unusual for such large gatherings to be seen. Individuals will disperse in search of food, and group size at any one time will depend upon the availability of the foods favored by this species. Their constant vocalizations, employed to warn of danger and in bonding behavior, mean they are often heard before they are seen.
The preferred diet of the black spider monkey is fleshy fruit, and the fruiting season in the Amazon basin is the best time to observe these and other species of South American monkeys. At times of the year when fruit is scarce, the spider monkey will adjust its diet accordingly, seeking out insects and also feeding upon leaves and even small animals.