Hi ,
Where we live, winter is not giving up! We've been in a deep freeze for almost two months.
But, have you ever wondered how the feet of a bird like this raven can stand the cold winter weather? Their feathers are incredibly designed to help retain body heat. But, what about the feet?! They look so scrawny and thin. You'd think they would freeze very fast.
But they don't. Here's why. First, there are very few blood vessels in the feet. They're mainly made up of bones and tendons with little muscle or nerve tissue. But, what about the blood that does indeed get there?
Birds make use of what is called a countercurrent heat exchange system. This is a unique system in which cold blood coming back from the feet travels through veins that are tightly grouped around arteries that are sending warm blood to the feet. Heat is then transferred from the warm vessels to the cool ones. Birds are then able to maintain warm body temperatures while their feet are actually cold. Furthermore, since bird circulation is so fast, blood doesn't
remain in the feet long enough to freeze. Lastly, there are a number of birds that have very few pain receptors in their feet, so they might not really feel the cold that much.
One article I read about this uses the term "miraculous adaptation" to describe this system. Their assumption is that millions of
years of lucky mutations and adaptations have produced this ability in birds. But, nature is packed with millions of examples of such "lucky" events. So many, in fact, as to render that idea absolutely absurd. Even one amazing feature like this in any animal would shout DESIGN!
So...."miraculous"? Yes, indeed! True of all of the Lord's creations!
