Lagomorphs, the biological order that includes rabbits and hares, are often mistakenly believed to hibernate to survive the cold winter months. The simple answer is that rabbits do not hibernate. Instead of entering a deep, prolonged sleep, they remain fully active throughout the year, relying on sophisticated physiological and behavioral adaptations to endure freezing temperatures and scarce food resources. Their survival strategy is one of continuous alertness and activity, contrasting sharply with the deep dormancy adopted by true hibernators.
What True Hibernation Entails
True hibernation is a specialized form of dormancy, or torpor, that allows certain mammals to survive long periods of cold and food scarcity by drastically reducing their metabolic function. A defining characteristic is the profound drop in the animal’s core body temperature, often falling to within a few degrees of the ambient temperature. For instance, a woodchuck’s body temperature can drop from a normal 98°F (36.7°C) to as low as 38°F (3.3°C) during this state. This deep physiological suppression also involves a severe slowdown of the heart and respiratory rates, allowing the animal to rely almost entirely on stored fat reserves for months. Rabbits cannot enter this controlled biological shutdown because they must maintain a high core body temperature and remain ready to flee from predators.
Rabbit Active Winter Survival Strategies
Rabbits employ a suite of active coping mechanisms to thrive in winter, rather than relying on a dormant state. One primary physiological change is the growth of a much thicker and denser winter coat. This additional layer of fur provides increased insulation against the cold, helping the rabbit maintain its high internal temperature without expending excessive energy.
Behaviorally, rabbits significantly alter their daily routines to conserve energy and find safety. They seek out or dig extensive burrows, or warrens, which offer a stable, insulated environment below the frost line, protecting them from harsh winds and snow. In severe cold, groups of rabbits may huddle together within these shelters to share warmth, reducing individual heat loss.
Activity above ground is often reduced to short, focused foraging trips, typically around dawn and dusk, when the risk of predation is lower. Their diet shifts dramatically from the abundant grasses and leafy plants of warmer months to tougher, more fibrous materials. When snow covers the ground, rabbits rely on gnawing the bark from young trees, twigs, and woody stems, which provides the necessary energy to fuel their high metabolic rate.
Although rabbits do not suppress their metabolism like true hibernators, their energy consumption is optimized during the winter. Studies on wild European rabbits have observed a reduction in heart rate—up to 30% lower—during periods of food scarcity. This reduction is an adaptive response to poor-quality winter forage, allowing them to lower their overall energy expenditure while still maintaining a stable body temperature.