Welcome to Word of the Week! Stay tuned for a new word each Friday to amp up your nature vocabulary!

Kleptothermy [KLEP-toh-thur-mee] (noun): Any form of thermoregulation by which an animal shares or steals the body heat of another animal. It may or may not be reciprocal, and can occur in both endotherms¹ and ectotherms ².

This time of year, a great example of non-reciprocal kleptothermy (heat-stealing) is happening in High Park with Garter Snakes.

Garter snakes have really complex systems of pheromonal communication. They can find other snakes by following the pheromone-scented trails that they leave behind. Male and female skin pheromones are very different from each other as to be immediately distinguishable. However, male garter snakes sometimes produce both male and female pheromones. During the mating season, this ability tricks other males into attempting to mate with them, which causes the transfer of heat in kleptothermy. This is an important advantage immediately after hibernation because it enables more activity. Male snakes giving off both male and female pheromones have been shown to have more copulations than normal males.

On your next spring visit to High Park, keep an eye out for Garter Snakes slithering around in the savannah and forest!

1. Also referred to as warm-blooded; Endotherms are animals that maintain a constant body temperature independent of the environment.
2. Also referred to as cold-blooded; Ectotherms are animals whose regulation of body temperature depends on external sources