Fecal plug

A fecal plug (sometimes referred to as a tappen) is a significant biological phenomenon observed in bears and other animals during hibernation. It is a dense mass of hardened feces that forms in the colon due to having remained in the intestine so long that the intestinal walls have absorbed the fluids out of it, leaving it dry and hard. An erroneous speculation still repeated in popular literature today is that bears prepare for hibernation by eating indigestible plant material to purge their digestive tracts and form a rectal plug that prevents further eating.

Formation
The fecal plug forms as the bear enters hibernation, a period characterized by a significant decrease in the animal's metabolic rate. During this time, bears do not eat, drink, urinate, or defecate. The plug consists of various materials ingested in the period leading up to hibernation, including undigested food, shed intestinal cells, ingested bedding materials, and even small rocks or soil particles consumed during grooming. A notable component of the plug is bits of dried, callused skin from the bear's footpads, which the bear may chew or lick during the later stages of hibernation.

Function
The primary function of the fecal plug is to prevent defecation during the months of hibernation, aiding in maintaining the bear's energy conservation. It acts as a physical blockage, ensuring that the bear remains in a state of minimal digestive activity. This adaptation is crucial for the bear's survival, as it allows for the conservation of energy and resources in an environment where food is scarce.

Expulsion
Upon the conclusion of hibernation in spring, the bear expels the fecal plug. This typically occurs near the entrance of the den and signifies the bear's return to its regular physiological functions. The expulsion of the plug is often one of the first activities a bear undertakes after emerging from its den, marking the end of its hibernation period.

Research and significance
The study of fecal plugs provides valuable insights into bear biology, particularly their hibernation habits and digestive processes. Researchers analyze the composition of the plugs to understand more about bear diet and health before hibernation. This research also contributes to broader ecological studies, as it helps in understanding the role of bears in their natural habitats.

Comparative biology
While the fecal plug is most notably associated with bears, similar phenomena have been observed in other hibernating animals. Understanding these similarities and differences can provide deeper insights into the evolutionary adaptations for hibernation across different species.

Impact on ecosystem
Bears play a significant role in their ecosystems, and the process of hibernation, including the formation and expulsion of fecal plugs, is part of this role. The nutrients and materials contained in expelled plugs can have an impact on the local flora and fauna, contributing to the nutrient cycle in bear habitats.

Cultural and historical perspectives
The fecal plug of bears has also found a place in human culture and history. Indigenous peoples and early naturalists have observed and documented this phenomenon, contributing to our understanding and the mythology surrounding bears and hibernation.