Why hibernate? Predator avoidance in the edible dormouse

Area of Science:

• Zoology
• Ecology
• Animal Behavior

Background:

• Hibernation and estivation are commonly believed to be responses to adverse environmental conditions like cold and food scarcity.
• The selective advantages of prolonged torpor, including hibernation and estivation, require further investigation.
• The edible dormouse (Glis glis) serves as a model species to explore these advantages.

Purpose of the Study:

• To investigate the primary selective advantages of hibernation and estivation in the edible dormouse.
• To challenge the prevailing view that hibernation is solely a response to poor environmental conditions.
• To explore the role of predator avoidance in the evolution of hibernation.

Main Methods:

• Observational study of edible dormice (Glis glis) focusing on hibernation and estivation patterns.
• Analysis of environmental conditions, food availability, reproductive success, and body condition in relation to torpor.
• Assessment of survival rates during active versus torpid periods.

Main Results:

• Edible dormice enter hibernation even in years with favorable conditions and ample food, indicating factors beyond resource scarcity.
• Predation, particularly by nocturnal owls, appears to be a significant driver for entering hibernation.
• Early emergence from hibernation allows for optimal territory and mate acquisition but increases spring predation risk.

Conclusions:

• Hibernation in edible dormice is predominantly a strategy to avoid predation, not just harsh environmental conditions.
• The timing of hibernation and emergence is linked to reproductive strategies and balancing predation risk.
• Predator avoidance is a key selective pressure favoring the evolution of hibernation across species.