The black spider monkey, Ateles chamek, inhabits the Amazon rainforests of Peru, Brazil, and Bolivia. These arboreal monkeys spend most of their lives in the forest canopy. Their diet is largely specialized, focusing on ripe fruits. While fruit constitutes the majority of their food, they also consume other plant materials.
Main Food Sources
Black spider monkeys are predominantly frugivores, meaning their diet centers on ripe fruits. Between 75% and 90% of their foraging time is dedicated to consuming ripe fruit. Figs are a significant part of their diet, sometimes making up almost 50% of what they eat, which is notable because figs are often considered a “fallback food” for other species. This high fruit intake provides them with carbohydrates and lipids, important energy sources for their active, arboreal lifestyle.
Beyond fruits, black spider monkeys supplement their diet with other plant parts and occasional animal matter. They spend about 13% of their foraging time eating leaves, preferring young leaves and leaf buds due to their higher protein content. Flowers, flower buds, and even bark or decaying wood can also be part of their diet, especially when fruit is less abundant. On rare occasions, they may consume insects like termites or caterpillars, and honey.
How They Find and Adapt Their Diet
They navigate the upper layers of the rainforest canopy, typically 25 to 30 meters above the ground, using their long limbs and prehensile tails. Their prehensile tail acts as a fifth limb, providing stability and allowing them to reach for food on fragile branches. This adaptation helps them access fruits widely dispersed throughout the canopy.
Their diet adapts to seasonal changes in food availability within their habitat. During periods of abundant ripe fruit, they rely heavily on this preferred food source, with over 85% of their diet consisting of ripe fruits. When fruit becomes scarce, they adjust by increasing their consumption of less preferred items like leaves, flowers, or even bark. Their intelligence and memory play a role in locating fruiting trees, as they remember when and where different fruit species are likely to be found.
Their Role in the Forest Ecosystem
Black spider monkeys play a significant role in maintaining the health and diversity of the tropical rainforest ecosystem. As large-bodied frugivores, they are effective seed dispersers. They often swallow whole fruits, and the seeds pass through their digestive system largely undamaged. These seeds are then excreted in their feces, often far from the parent tree, which helps in colonizing new areas and reduces competition among seedlings.
This process of seed dispersal is important for forest regeneration and the genetic diversity of plant populations. Studies indicate that most seeds consumed by black spider monkeys are passed intact and have a good chance of germinating, often with a nutrient-rich package from the feces to aid their growth. Their movements across large home ranges further enhance the dispersal of seeds across the forest.