Brumation is a natural biological process that allows certain animals to survive periods of environmental challenge. This state of dormancy is a key survival mechanism, enabling survival when conditions become too harsh for normal activity.
Understanding Brumation: A Specialized Dormancy
Brumation is a period of winter dormancy primarily experienced by cold-blooded vertebrates, such as reptiles and amphibians. It is a physiological state involving a slowing of metabolic processes, reduced activity, and minimal food intake. The term “brumation” was coined in 1965 by biologist Wilbur Waldo Mayhew to differentiate this process in ectotherms from hibernation in endotherms.
A key distinction between brumation and hibernation lies in the animal’s ability to rouse; brumating animals can periodically wake to drink water, unlike hibernating mammals. Both states are triggered by changing day length and temperatures. However, brumating animals do not rely on fat reserves like hibernators, and their body temperature largely mirrors the environment. Hibernation involves a regulated drop in body temperature and a deep, prolonged sleep, while brumation is a less profound state of dormancy where the animal may still be somewhat aware.
The Body’s Internal Adjustments
During brumation, an animal’s body undergoes significant internal changes to conserve energy and survive without consistent food intake. A primary adjustment is a substantial decrease in metabolic rate, meaning the body requires far less energy to sustain its functions.
Heart rate and respiration also slow considerably, reducing the energy needed to maintain basic bodily functions. While hibernators primarily rely on stored fat, brumating reptiles and amphibians also utilize glycogen reserves for energy. The digestive system becomes largely inactive, and animals typically stop eating as their metabolism is too low to process food properly. Hormonal fluctuations, such as a decrease in thyroid hormone levels, contribute to this reduced metabolic state. The immune system may also operate less effectively during this period, making maintaining a clean environment important for captive animals.
External Triggers and Behavioral Preparations
Environmental cues play a significant role in initiating brumation. The primary triggers are decreasing temperatures and shortening daylight hours, signaling the onset of colder seasons. As cold-blooded creatures, reptiles and amphibians rely on external heat sources, so these environmental shifts prompt them to prepare for dormancy. Humidity changes can also act as cues for brumation.
Before entering brumation, animals exhibit specific preparatory behaviors. They often reduce their food intake, eventually stopping altogether, to ensure their digestive tracts are clear. Undigested food remaining in the gut during brumation can spoil and cause illness. Animals also seek sheltered locations, such as burrows, crevices, or underground dens, where temperatures are more stable and protection from extreme cold is available.
Guidance for Owners of Brumating Pets
For owners of pets that naturally brumate, providing appropriate conditions is important for their well-being. Ensuring proper environmental temperatures is important, with an ideal range typically between 40-60 degrees Fahrenheit (4-15 degrees Celsius) to allow for metabolic slowdown without risk of freezing. Gradual adjustments to temperature and lighting, mimicking natural seasonal changes, help signal the pet to enter brumation.
Maintain access to fresh water, as brumating animals may periodically wake to drink. Minimal handling and disturbance are recommended to allow the pet to remain undisturbed. It is also important to ensure the pet is healthy and has sufficient body weight before brumation, as young or unhealthy animals may not survive the process. Consulting a veterinarian is advisable if there are concerns about the pet’s health, or if it fails to enter or exit brumation as expected.
The Reawakening Process
As environmental conditions improve, animals gradually emerge from brumation. Rising temperatures and increasing daylight hours are the primary cues that trigger this reawakening, signaling their internal biological clock that it is safe to resume normal activity.
The return to an active state is a slow process. Pets will gradually increase their movement and their appetite will return, requiring careful monitoring of food intake. Hydration needs also increase as they transition back to their regular behaviors. Increase enclosure temperatures and lengthen daylight exposure gradually to avoid overwhelming the animal during this transition.