Gorillas are the largest primates on Earth, with adult males often reaching weights that make them formidable ground-dwellers. Their sheer size and robust build lead to a common misunderstanding about their movement through the dense forest canopies. While many smaller primates are celebrated for their aerial agility, gorillas do not engage in brachiation, which is the specialized form of locomotion involving swinging arm-over-arm from branches. This difference in movement is a direct result of physical adaptations separating them from their smaller, acroboreal cousins.
Why Gorillas Do Not Swing
The primary reason gorillas do not swing is their immense body size and weight. Adult male gorillas, known as silverbacks, can weigh between 350 and 450 pounds, a mass that prevents sustained suspensory movement. Brachiation is a specialized behavior where the forelimbs alone bear the entire body weight, propelling the animal through the air in a pendulum-like motion. This technique is successful for small primates like gibbons, which have proportionately long arms and specialized joints.
Gorillas have a heavier skeletal structure with denser bones, contributing to their overall mass. Their anatomy is built for stability and ground-based power rather than aerial flexibility. The force required for a gorilla to support its weight with one arm would place damaging stress on the shoulder, elbow, and wrist joints. They lack the specific adaptations needed for the high-energy, low-stability aerial movement that defines true brachiation.
How Gorillas Move on the Ground
Gorillas are predominantly terrestrial, spending the majority of their lives traveling on the forest floor. Their characteristic movement is knuckle-walking, a unique type of quadrupedal locomotion. This technique involves supporting their body weight on the dorsal surfaces of their middle fingers, which are held flexed inward. This posture is employed for over 80% of their movement repertoire.
Knuckle-walking efficiently distributes their heavy mass. By walking on the knuckles, gorillas protect the soft tissues of their palms and the delicate structures of their wrist joints from repeated impact. The gorilla’s knuckle-walking is described as “columnar,” where the wrist is kept in a straight, neutral alignment, maximizing stability. Their forelimbs primarily act as steadying supports, while their heavily muscled hindlimbs generate the majority of the propulsive force.
Climbing and Arboreal Behavior
While gorillas do not swing, they are capable climbers, especially in certain populations. They are primarily terrestrial, but they regularly ascend trees for specific reasons. Climbing is common for younger and smaller gorillas, but even large silverbacks, weighing up to 375 pounds, will climb if the branches can bear their weight.
Their arboreal activity focuses on accessing food sources like fruit and leaves, and constructing sleeping nests high above the ground. Western Lowland Gorillas are known to spend a substantial portion of their day in trees, with adult females sometimes spending over 30% of their time aloft. Gorillas climb quadrupedally, using all four limbs to grip and move along the branches, maintaining a stable, controlled ascent.