Here we have Tom, Thomas and Tommy, Ogden Nature Center's rambling and rambunctious turkeys.And look! They're wearing their snow boots! OK, not really. In fact, the feet of our familiar feathered trio don't seem to have anything to keep them from freezing. So how come they don't freeze?
The turkeys' feet, like those of most birds, have little in them to freeze. Basically, they are made of bone and the hard, scaly covering that protects them. But the turkeys' feet have something very important -- and different than humans -- inside their legs and feet that not only helps prevent their feet from freezing, but also helps keep the birds warm.
Each of their legs has an artery and a vein inside, with the artery carrying the blood away from the bird's heart and the vein circulating it back to the heart. The artery and vein are positioned right next to each other, so that as the warm blood travels through the artery from the bird's body and into its leg and foot, it gradually warms the cool blood in the vein that is returning to the body from the bird's lower extremity.
This heat transfer helps to keep the bird's feet and legs from freezing and it also ensures that the blood returning to its body is warm. It's as if Tom, Thomas and Tommy are walking around atop their very own space heaters!
Post by Susan Snyder, ONC Teacher-Naturalist (naturalist2@ogdennaturecenter.org)
Photo by Brandi Bosworth, ONC Public Relations Specialist (info@ogdennaturecenter.org)
