Dvaleperioder

Dvaleperioder, often translated as torpor or dormancy, refers to a state of reduced physiological activity in animals. This state is characterized by lower body temperature, slowed breathing and heart rate, and a decreased metabolic rate. Dvaleperioder are typically adaptations to harsh environmental conditions, most commonly periods of extreme cold or scarcity of food.

There are several types of dvaleperioder. Daily torpor is a short-term state, often lasting only a few hours within a 24-hour cycle, and is common in small mammals and birds to conserve energy during cold nights or when food is unavailable. Seasonal dormancy, or hibernation, is a longer-term state, lasting weeks or months, and is observed in animals like bears, squirrels, and bats. Bears, while often called hibernators, enter a less profound state of dormancy compared to true hibernators, as their body temperature does not drop as drastically. Another form is aestivation, a dormancy period triggered by heat and drought, seen in some amphibians, reptiles, and invertebrates.

During dvaleperioder, animals rely on stored body fat for energy. Their ability to wake up from these states varies; true hibernators may spend significant time and energy rewarming their bodies, while animals in daily torpor can arouse more quickly. These physiological states are crucial for the survival of many species in challenging ecological niches.