It’s a cold night in a Canadian forest. Temperatures are below freezing, snow is on the ground and most animals remain hidden to avoid the harsh conditions. But one creature is braving the cold weather.
Blue-spotted salamanders (Ambystoma laterale) are on the move. These small amphibians have left their underground winter refuges and started migrating toward breeding pools, often risking freezing.
For animals whose body temperature closely follows the environment, like salamanders, freezing can be deadly, as the formation of ice inside the body can damage cells and disrupt vital functions. However, blue-spotted salamanders remain active and apparently unharmed under the freezing conditions.
As a group of biologists who study how temperature shapes animal behaviour and physiology, our team has been long fascinated by animals that keep active at low temperatures.
In a recent study, colleagues and I documented salamanders migrating with body temperatures below 0 C in the wild. Our findings highlight field-based evidence that these amphibians can function at sub-zero temperatures without freezing. In doing so, salamanders are possibly extending their breeding season.