The Arctic Hare (Lepus arcticus) is adapted to survive the unforgiving conditions of the Arctic tundra. This large species inhabits the treeless biomes of Northern Canada and Greenland, where food availability fluctuates dramatically throughout the year. Its survival is linked to a highly flexible and seasonal diet, which shifts in response to the brief summer thaw and the long winter.
Summer Diet Grazing on Abundant Vegetation
The summer months, typically May through August, offer a period of abundance when snow cover recedes, exposing low-lying tundra vegetation. The hare’s diet becomes highly diverse, focusing on rapidly acquiring energy and nutrients to build fat reserves for the coming cold season.
Hares graze on soft, digestible plants, including willow shoots, grasses, flowering plants, buds, leaves, and berries, which provide concentrated sugars and proteins. Legumes often dominate the summer diet, sometimes constituting up to 70% of their intake. This period of high-quality grazing allows the hares to maximize their body mass, a physiological necessity for insulating against severe winter temperatures.
Winter Diet Surviving on Woody Plants and Roots
The onset of winter forces a challenging shift in the Arctic Hare’s diet as the tundra locks under deep snow and ice. Survival depends on accessing scarce, low-nutrient, fibrous woody plants. The dwarf willow is the most important plant during this season, with its twigs, bark, and roots forming the bulk of the winter menu.
Finding food requires specialized foraging behavior; hares must actively dig through packed snow to reach buried vegetation, a process called cratering. They rely on a developed sense of smell to locate food sources hidden beneath the frozen surface. When willow is less available, hares consume the bark and twigs of birch, along with hardy lichens and mosses that grow close to the ground. This effort to dig for tough, woody material is a constant trade-off between energy expenditure and nutrient gain.
Specialized Feeding Adaptations
The Arctic Hare possesses specific anatomical features that enable it to process a diet of variable and low nutritional quality. Their dentition is adapted for consuming tough materials, featuring strong, long incisors used to gnaw on bark and pull plant matter from frozen ground. This allows them to utilize food sources inaccessible to many other tundra herbivores.
The hare’s digestive system extracts maximum nutrition from fibrous plants through hindgut fermentation. To capture all available nutrients, the Arctic Hare practices cecotrophy, re-ingesting soft fecal pellets produced in the cecum. This second pass allows for the complete breakdown of cellulose and the absorption of microbial proteins and B vitamins. Additionally, hares consume snow for hydration when open water is unavailable during winter. They also exhibit a low basal metabolic rate, which helps conserve energy reserves on a minimal winter diet.