The snowshoe hare is a small mammal of the North American wilderness, recognized for its survival strategies in environments defined by heavy snow and cold temperatures. This common lagomorph, a relative of rabbits and pikas, has evolved physical traits that allow it to thrive where many other animals struggle to find footing. Its life is dictated by the seasons, exhibiting a unique biological rhythm that includes a dramatic shift in appearance. The hare’s ability to change its coat color and navigate deep snow is central to its survival in northern ecology.
Defining Physical Traits and Seasonal Camouflage
The snowshoe hare, Lepus americanus, is named for its oversized hind feet. These feet are proportionally much larger than those of other hares and are covered with a dense mat of stiff fur that acts like natural snowshoes. This design increases the surface area, efficiently distributing the hare’s weight and preventing it from sinking into soft snowpack, allowing rapid travel across winter landscapes. The fur on the soles also provides insulation, protecting the foot pads from intense cold.
The hare’s second adaptation is seasonal camouflage, achieved through molting twice a year. In summer, the coat is a mottled rusty or grayish-brown, blending with the forest floor and underbrush. As days shorten in autumn, the change in photoperiod triggers a molt that replaces the brown fur with an almost entirely white coat.
The white winter coat is significantly thicker than the summer pelage, offering improved insulation. This seasonal color change is a fixed biological response governed by the light cycle, not the immediate presence of snow. This reliance on photoperiod can sometimes lead to a “color mismatch,” increasing vulnerability when a white hare is on a snowless brown background. The reverse molt occurs in spring as days lengthen, returning the hare to its brown summer appearance.
North American Range and Habitat
The snowshoe hare is distributed across the northern half of the continent, extending from Alaska and across Canada. Southward, its distribution follows the mountainous and high-altitude regions of the contiguous United States. These include the Rocky Mountains, the Cascade Mountains, and the Appalachian Mountains, as well as the northern forested regions of states like Minnesota and Michigan.
The preferred environment is characterized by dense cover, necessary for predator evasion and shelter. Snowshoe hares are closely associated with the boreal forest, dominated by coniferous trees like spruce and fir, and mixed woodlands. They utilize areas with a thick understory, brushy thickets, and wooded swamps that offer adequate concealment. Mature spruce-fir forests are favored because these trees retain low-hanging crowns that provide protective cover and a consistent winter food supply.
Feeding Habits and Reproductive Cycle
The snowshoe hare is an opportunistic herbivore whose diet shifts dramatically with seasonal vegetation availability. During summer, the diet consists of various soft plants, which supports the animals during their peak reproductive period.
Summer Diet
- Grasses
- Clover
- Ferns
- Leaves of young woody plants
- Herbaceous plants and flowers
The onset of winter necessitates a diet change due to the scarcity of green plants. Hares survive by browsing on the tougher, less digestible parts of woody vegetation.
Winter Forage
Winter forage includes:
- Buds
- Small twigs
- Bark of trees like aspen and willow
- Needles of evergreen species
To maximize nutrient extraction from this fibrous material, hares practice coprophagy, reingesting specialized soft fecal pellets for a second pass through the digestive system.
The reproductive cycle begins in early spring, typically March or April, and extends through summer. Females produce multiple litters each year, ranging from two to four, depending on conditions. The gestation period averages 36 to 37 days.
The young, known as leverets, are born in an unlined nest or depression. Like all hares, the young are precocial: they are born fully furred, with eyes open, and are able to move shortly after birth. Litter sizes typically range from three to five young. A female can become pregnant again shortly after giving birth, allowing rapid population increase during favorable conditions.
Role in the Ecosystem and Population Dynamics
The snowshoe hare holds an important position in the boreal forest ecosystem as a primary prey species for numerous predators. It supports a wide array of carnivores and raptors, including coyotes, foxes, great-horned owls, and goshawks. Of all the predators, the Canada lynx is the most closely tied to the hare, as its survival depends almost exclusively on the hare population.
This close relationship results in the 10-year hare cycle, one of the most famous examples of population dynamics in nature. Across the northern forests, snowshoe hare populations experience fluctuations, with numbers peaking and then crashing in a cycle that averages 8 to 11 years. The hare’s abundance dictates the reproductive success and population size of its specialized predators, particularly the lynx.
When hare numbers are high, predators flourish, but intense predation pressure eventually drives the hare population into a sharp decline. Studies suggest that high mortality from predation is the immediate cause of the population crash, with chronic stress from constant predator chases also playing a role in reducing the hare’s reproductive rate. As the hare population collapses, the predators soon follow, creating a delayed, oscillating pattern where the predator peak occurs one to two years after the prey peak. The cycle then begins again as low predator numbers allow the hares to recover and multiply.