April 30, 2020

BONUS: Animal dormancy isn’t just for the winter

Compare estivation, hibernation and brumation

Hibernation isn’t the only form of dormancy for animals, and winter isn’t the only season for inactivity among certain species.

Right now, most humans and animals are celebrating the warmth of spring with thoughts of a sun-filled summer are dancing in our heads. But hot and dry conditions don’t make all animals happy. For some, like many reptiles and amphibians, warmer weather causes them to do something called estivate.

Estivation is when animals are dormant because weather conditions are very hot and dry. Their breathing rate, heart rate and metabolic rate decrease to conserve energy under these harsh conditions. These animals will find a spot to stay cool and shaded.
In addition to many reptiles and amphibians, some mollusks, insects, fish and mammals will estivate as well.

Like estivation, hibernation and brumation are forms of dormancy that some animals go through, but these occur when turns cold rather than hot. These terms can be confusing because there are similarities between them all, but there are distinct details that make each process different.

Hibernation is a state of dormancy in endotherms, or warm-blooded animals. With hibernation, an animal’s body temperature, heart rate, breathing rate and metabolic rate slow down during the winter months. This occurs so the animal can conserve energy and survive during the cold months.

Animals can hibernate for several days, weeks or months, depending on the temperature in the area and the individual animal’s condition. Rodents such as the chipmunk and ground squirrel go through true hibernation.

Brumation is known as the hibernation for cold-blooded animals. Ectotherms rely on their environment to regulate their body temperature. Cold temperatures cause reptiles and amphibians to hide underground, in rock crevices and in burrows to stay warm and safe. Their activity, body temperature, heart rate and respiratory rate drop like in hibernation.

Cold-blooded animals will move on warmer winter days and find water, unlike hibernators, who are in a deep sleep and do not move at all.

Whether it is hibernation, brumation, estivation or a combination of these processes, animals have an amazing ability to adapt and survive in their different environments. The environment that an animal lives in greatly affects its dormancy behavior.