Gorillas build nests, or sleeping platforms, as a fundamental part of their daily life in the wild. This behavior is universal across all gorilla subspecies, serving as a biological requirement for rest and survival. These temporary structures are constructed every evening using local vegetation, providing a secure and comfortable spot for the night. Building a fresh nest daily highlights the intelligence and adaptability of these great apes.
The Essential Functions of Gorilla Nests
Gorilla nests serve multiple biological functions that contribute directly to the health and survival of the animal. A primary benefit is the insulation provided, aiding in thermoregulation during long overnight rest periods. The layered vegetation acts as a barrier, preventing heat loss to the cold or damp ground, which is particularly important in the high-altitude forests of Mountain gorillas where temperatures drop significantly at night.
The practice of building a new nest nightly is a behavioral adaptation that promotes hygiene and avoids parasite buildup. By rarely reusing a sleeping site, gorillas minimize their exposure to accumulated waste, which can harbor ectoparasites like ticks or fleas, as well as pathogens. This constant relocation helps maintain a cleaner sleeping environment, a necessity in the humid, tropical environments where many gorilla populations reside.
Nests also enhance safety and security, especially for younger individuals. While adult gorillas have few natural predators, infants are at greater risk, and the nest provides a secure, often slightly elevated, space. Constructing a fresh nest in a new location daily reduces predictability, making it harder for potential predators to track the group to a repeatedly used site.
Construction Techniques and Material Selection
Gorillas begin the process of nest construction shortly before dusk, once their late-afternoon feeding session concludes. The entire process is relatively quick, typically taking an individual less than 10 minutes to complete a night nest. The location is chosen based on factors such as ground stability, wind exposure, and the presence of suitable materials.
The construction technique involves the gorilla bending and interlacing branches, stems, and vines to form a stable, mattress-like base. Larger, more rigid vegetation is used for the structural frame, while softer materials like leaves and pliable stems are layered on top for cushioning and insulation. This layering technique often results in a round, bowl-like structure with a raised rim, which helps secure the animal and provides a sense of enclosure.
The specific materials used depend heavily on the local flora, often including broad-leafed herbs, bamboo, or wild celery. Some plant species may offer natural insect-repelling compounds. Nest-building is a learned skill; juveniles begin practicing construction around three years of age, though they sleep with their mothers until then. For arboreal nests, the gorilla selects a strong fork in a tree limb and weaves the materials across it to create a secure platform.
Variability in Nesting Behavior
Nesting behavior is not uniform across all gorillas and varies significantly based on the time of day, environment, and the individual’s size or social role. Gorillas construct two main types of nests: robust night nests and simpler day nests. Night nests are purpose-built for eight to twelve hours of sleep, requiring a more elaborate and sturdy structure.
Day nests, or “day beds,” are more rudimentary resting spots used during midday breaks for napping, grooming, or relaxation, and are less structurally complex than night nests. Environmental factors strongly influence the choice between an arboreal (tree) or terrestrial (ground) nest. While Mountain gorillas are nearly exclusively terrestrial, Western Lowland gorillas are more likely to build arboreal nests, especially in areas where ground moisture is high or when feeding on fruits high in the canopy.
Nearly every gorilla, from juvenile to adult, builds its own individual nest, except for infants who share the mother’s nest. Silverback males, due to their body weight, generally prefer to construct their nests on the ground, sometimes using a simpler bare-earth scrape.
Females and non-silverback individuals more often utilize arboreal sites. The entire group typically nests in close proximity, with the silverback often establishing his nest slightly apart to function as a defensive perimeter.