Strange But Practical: Why Snowshoe Hares Eat Their Own Feces
What is the most disgusting behavior that you have ever witnessed? My guess would be that it was something you saw a domestic pet or wild animal do. As humans, we do not often understand the seemingly bizarre and foreign behaviors that are carried out by the animals around us. Right here in the heart of the Rocky Mountains we are in the presence of an animal whose behavior would make any of us nauseated.
The snowshoe hare is one of the more familiar mammals occurring within the coniferous forests of western Montana. These particular animals, as well as other hares and rabbits, exhibit a behavior known as coprophagy. Coprophagy is the ingestion of feces.
Humans do not often witness this striking phenomenon in nature because it generally occurs in the evening when the hares are most active. A person observing this activity for the first time might wonder why an animal would eat its own dung. The fact of the matter is that coprophagy is a normal behavior, and it plays a vital role in the normal digestive processes of the snowshoe hare.
The snowhshoe hare is an herbivore that changes its food preferences from season to season. The winter diet of hares consists of the bark and twigs of coniferous and deciduous trees. Needles of spruce trees are also a preferred winter food. Hares eat herbs and deciduous leaves during the summer. This high fiber diet makes it difficult for the digestive tract to extract a sufficient amount of nutrients.
The enzymes within the stomach of the hare are unable to break down most of the plant material that is ingested. Plant parts that are resistant to digestion quickly pass through the stomach and small intestine of the animal. Symbiotic bacteria residing within an outpocketing of the animal’s intestines are able to break down the plant fiber. While digesting the plant material, the microorganisms readily make proteins and B-vitamins available to the hare. It just so happens that the hare needs these substances to maintain appetite and health.
The interesting observation is that the intestinal outpocketing, or cecum, is located below the small intestine, which is the major point of nutrient absorption in all mammals. In essence, the microorganisms free up the essential chemicals after the hare has absorbed the nutrients made available through its own enzymes. Coprophagy enables the animal to salvage proteins and vitamins produced in the cecum that would otherwise be lost for good. Ingesting the “nutritional,” high-protein, high-vitamin-content feces does this.
Coprophagy permits the snowshoe hare to extract enough nutrients from its low-quality food to remain healthy. The behavioral action of eating one’s own feces may seem bizarre to us, but that is because we experience a totally different set of living conditions than the hare. Mother Nature works in a very efficient manner. Studies have shown that rabbits, when placed on a limited diet and prevented from ingesting their own feces, have become quite weak and unhealthy. So don’t just poke fun at animal behaviors that seem quite ridiculous to you--because they likely play important roles in the lives of the animals that conduct them.
'Field Notes' is produced by the Montana Natural History Center.