Cold Feet?
I have sometimes wondered why birds feet don't freeze in the winter. Plagiarised from All About Birds.
Songbirds do get very cold feet: the surface temperature of their toes may be barely above freezing even as the bird maintains its core body temperature above 100°F (38°C). But most birds don’t succumb to frostbite because there is so little fluid in the cells of their feet, and their feet are mostly tendons and bones with little muscle or nerve tissue.
Birds also have a countercurrent heat exchange system in their legs and feet—the blood vessels going to and from the feet are very close together, so blood flowing back to the body is warmed by blood flowing to the feet. The newly cooled blood in the feet lowers heat loss from the feet, and the warmed blood flowing back into the body prevents the bird from becoming chilled. And because bird circulation is so fast, blood doesn’t remain in the feet long enough to freeze.
What did we do before the internet, I would have had to spend days in the library to find this out!
Cold Feet?
I have sometimes wondered why birds feet don't freeze in the winter. Plagiarised from All About Birds.
Songbirds do get very cold feet: the surface temperature of their toes may be barely above freezing even as the bird maintains its core body temperature above 100°F (38°C). But most birds don’t succumb to frostbite because there is so little fluid in the cells of their feet, and their feet are mostly tendons and bones with little muscle or nerve tissue.
Birds also have a countercurrent heat exchange system in their legs and feet—the blood vessels going to and from the feet are very close together, so blood flowing back to the body is warmed by blood flowing to the feet. The newly cooled blood in the feet lowers heat loss from the feet, and the warmed blood flowing back into the body prevents the bird from becoming chilled. And because bird circulation is so fast, blood doesn’t remain in the feet long enough to freeze.
What did we do before the internet, I would have had to spend days in the library to find this out!