All birds have blood flow to their feet, or those cells would be dead. But the two vessels (artery and vein) lie very close together, and as heat moves toward cold, this works quite well.
The warm blood from the body flows to the feet and cools a great deal, this cold blood would cause a sever shock to the body if it returned cold, but the blood coming from the body is quite warm, and that heat is transferred to the feet, and to the blood returning to the body. This keeps both the feet and the blood from freezing solid.
If you compare the volume of the feet to the volume of the rest of the body, the feet have very little, and the blood moves quickly through them, constantly. Allowing them to withstand standing on ice and snow, oblivious to the temperature.
That being said, birds can loose toes in cold enough temperatures. I had one once, that I got from someone else, but it never seemed to bother her.
Mrs K
The warm blood from the body flows to the feet and cools a great deal, this cold blood would cause a sever shock to the body if it returned cold, but the blood coming from the body is quite warm, and that heat is transferred to the feet, and to the blood returning to the body. This keeps both the feet and the blood from freezing solid.
If you compare the volume of the feet to the volume of the rest of the body, the feet have very little, and the blood moves quickly through them, constantly. Allowing them to withstand standing on ice and snow, oblivious to the temperature.
That being said, birds can loose toes in cold enough temperatures. I had one once, that I got from someone else, but it never seemed to bother her.
Mrs K
