17 Feb 2023

Deer Sleeping in Snow

by Jan Thornhill

Deer sleeping forms. 

They're pretty compact when it's below freezing, with their back legs tucked under. Deer put on a lot of fat in the fall, and their winter hair is hollow for added insulation. 


 

Their skinny, uninsulated legs are heat exchangers – warm blood pumped from their core runs alongside veins filled with cooled blood. This arrangement preheats the cooler blood so it's not super-cooled before it returns to the deer's heart.



Jan Thornhill is an award-winning (multiple awards!) Canadian author and illustrator. Her books include The Triumphant Tale of the House Sparrow, The Tragic Tale of the Great Auk, and she has rescued a turtle (read about it at this link). These photos are by Jan Thornhill.

1 comment:

Paula Johanson said...

Those heat exchanging blood vessels occur in the legs of ducks, too!
Such charming snow impressions of deer resting or sleeping! Did you know that similar but larger impressions in snow and earth have been found by people who swear this place must be where a sasquatch slept?! Even though the impressions are probably made by moose or elk, it's understandable why some people would see the shape of a Bigfoot rather than a huge deer.