Spider monkeys, primates belonging to the genus Ateles, are native to the tropical forests stretching from southern Mexico down to Brazil. Characterized by extremely long limbs and a long tail, they primarily rely on a plant-based diet. While the question of whether they eat “meat” is common, the answer is no; they do not hunt or consume vertebrate prey. Any animal matter they consume is minimal and consists almost entirely of invertebrates.
The Primary Role of Frugivory
The spider monkey is a prime example of a frugivore, specializing in eating fruit. Ripe fruit makes up the vast majority of their diet, consistently reported to be between 71 and 90 percent of their total food intake. They are often described as “ripe fruit specialists” because they seek out mature, soft fruits from hundreds of different plant species.
This intense focus on fruit provides the high levels of soluble carbohydrates and energy needed to fuel their active, arboreal lifestyle. Spider monkeys swallow whole fruits and their seeds, which pass through their digestive tract largely intact. This behavior makes them highly effective seed dispersers, playing a significant role in the regeneration of the tropical forests they inhabit.
When fruit becomes temporarily scarce, the monkeys shift their consumption to supplementary plant materials. These fallback foods include young leaves, flowers, and even tree bark. Young leaves are important because they are easier to digest and provide necessary protein when fruit is not abundant.
Defining the Protein Component
Although their diet is heavily plant-based, spider monkeys are technically considered omnivores due to a small but regular intake of animal protein. This component is not “meat” but consists of a variety of small, easily accessible invertebrates. They consume insects, insect larvae, and occasionally eggs, which provide a concentrated source of nutrients lacking in fruit.
This minor animal matter intake supplies essential protein and minerals that support their large body size and demanding metabolism. The consumption of these items often increases during periods when preferred ripe fruit is not readily available. They will also occasionally consume arachnids, such as spiders, when foraging through the canopy.
This animal consumption remains a fractional part of their overall diet. Their digestive systems are primarily adapted for processing large volumes of plant matter, not for digesting large amounts of animal flesh.
Specialized Foraging Behavior
Spider monkeys spend a significant portion of their day actively foraging for food, an activity influenced by their unique social and physical adaptations. They are almost exclusively arboreal, spending their lives high in the forest canopy, typically between 25 and 30 meters above the ground. Their long, powerful prehensile tail acts as a fifth limb, allowing them to hang and maneuver through the branches while plucking fruit with their hands.
Their social structure, known as fission-fusion, is directly linked to their feeding strategy. Large groups of up to 35 individuals split into smaller, temporary subgroups, which can range from two to 17 animals, when searching for food. This splitting behavior helps to minimize feeding competition for fruit, which is often found in scattered, temporary patches.
The smaller foraging groups allow the monkeys to exploit widely distributed fruit resources more efficiently without having to compete intensely with every other individual. Research indicates that individual monkeys make decisions about subgroup size based on the availability of fruiting trees, often pooling their collective knowledge of the environment to locate the best food sources.