Wild rabbits, such as the European Rabbit (Oryctolagus cuniculus) and North American Cottontails (Sylvilagus spp.), are obligate herbivores. Their survival depends entirely on a diet composed strictly of vegetation. Their anatomy, from teeth to gut, is adapted to process large volumes of fibrous plant material, which dictates their feeding behaviors and survival strategies.
Primary Forage: Grasses and Herbaceous Plants
The foundation of a wild rabbit’s diet during periods of abundance consists almost entirely of fresh grasses and low-growing herbaceous plants. They engage in constant grazing, consuming a wide variety of grasses, including species like timothy, ryegrass, and meadow fescue. This high-fiber, low-nutrient forage is consumed in large quantities, requiring rabbits to spend a significant portion of their waking hours feeding.
The continuous chewing action is necessary for maintaining dental health. Rabbits possess aradicular hypsodont teeth, meaning all their teeth grow continuously throughout their lives. The abrasive cellulose in grass wears the teeth down at a rate that matches their growth, preventing painful overgrowth. Rabbits also seek out softer, more nutritious herbaceous plants, such as clover, dandelion greens, and various wild herbs. These secondary sources offer higher concentrations of protein and vitamins, though they represent a smaller percentage of the total volume consumed.
Seasonal Shifts and Emergency Foods
The wild rabbit’s diet transforms when lush, green forage diminishes. As grasses dry out and become dormant, the rabbit shifts to tougher, lower-quality foods. This strategy involves seeking out woody browse material that is largely ignored during the growing season.
Their winter diet often includes the bark of trees, small twigs, and the dormant buds of shrubs. These woody items offer lower nutritional density but provide the roughage and calories needed to survive periods of scarcity. Rabbits may also dig through snow or soil to find inactive plant roots or consume dried, fallen leaves and seeds. European rabbits, for example, consume acorns and the bark of trees like willow or apple when preferred food is unavailable.
The Digestive Process: Cecotrophy
To maximize nutrient extraction from their high-fiber diet, rabbits rely on a unique digestive adaptation called cecotrophy. Rabbits employ hindgut fermentation in the cecum, a specialized pouch situated between the small and large intestines. Microorganisms within the cecum break down cellulose and other complex carbohydrates that were indigestible during the first pass.
This process results in two distinct types of fecal matter. The first is the familiar hard, dry pellet, which is the waste product composed of indigestible fiber. The second is the cecotrope, a soft, moist pellet coated in mucous, produced four to nine hours after a meal. The rabbit re-ingests the cecotrope directly from the anus, allowing for a second passage through the digestive system. This re-ingestion is essential for absorbing proteins, short-chain fatty acids, and B vitamins, such as B12, synthesized by the gut microbes.