YELLOWSTONE NATIONAL PARK — On Monday, Dec. 23, Yellowstone National Park (YNP) shared a few photos to bring attention to the built-in winter survival tool of wolves, coyotes and foxes that helps them have effective and paw-sitive hunting experiences this season.
According to YNP, these three species utilize countercurrent circulation, a heat exchange system that keeps them warm while conserving body heat.
“Cold temperatures cause surface blood vessels to constrict, shunting blood into deeper veins that lie close to arteries,” YNP writes on its website. “Cooled blood returning from extremities is warmed by arterial blood traveling towards the extremities, conserving heat.”
Yellowstone Forever (YF) further explains this as an adapted circulatory network that allows an animal’s feet to stay very cold, but just warm enough to avoid tissue damage.
YNP emphasizes that this fine line of blood flow to the paws is perfect for hunting in the snowy landscapes of the Greater Yellowstone Ecosystem.
And these three iconic species aren’t the only ones utilizing this circulatory technique. Both mammals and waterfowl exhibit countercurrent heat exchange in limbs that enables them to operate in the snow and stand in cold water.
