Tortoise Hibernation Welfare | Animal Welfare Hub

How to safely manage hibernation for Mediterranean tortoises to protect health and welfare.

Key Facts

Mediterranean tortoises including Hermann's and Spur-thighed tortoises naturally hibernate in winter
Failure to hibernate appropriately can cause health problems including eye swelling and kidney damage
Body weight assessment before hibernation using the Jackson Ratio guides safe hibernation decisions
Underweight tortoises should not be hibernated — risks include death from fat reserve depletion
Refrigerator hibernation provides controlled, safe temperatures between 4-8 degrees C
Sick or recently treated tortoises require veterinary assessment before hibernation decisions are made

Welfare Considerations

Tortoise hibernation is a welfare-significant annual event that requires careful preparation and monitoring to be safe. Tortoises hibernated at inappropriate weight, temperature, or health status risk dying during hibernation — a silent death that owners may not discover for weeks. Conversely, tortoises prevented from hibernating when healthy may develop health problems from abnormal photoperiod and temperature exposure. The Jackson Ratio provides an accessible tool for assessing hibernation fitness, and refrigerator hibernation allows temperature-controlled, monitored hibernation that substantially reduces risk compared to outdoor hibernation in variable climates.

What You Can Do

Assess tortoise body weight using the Jackson Ratio before deciding whether to hibernate
Do not hibernate tortoises that are underweight, sick, or have received veterinary treatment recently
Use refrigerator hibernation for reliable temperature control and regular monitoring access
Weigh tortoises monthly during hibernation and rouse any that lose more than 10% of starting weight
Consult a reptile-experienced veterinarian about hibernation decisions for any tortoise with health concerns