Archived posting to the Leica Users Group, 2008/01/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Richard Taylor <r.s.taylor@comcast.net> wrote: > ... Here's what came back from Ask A Scientist - Zoology Archive: > " ... ducks have what is known as a counter current heat exchange > mechanism in their legs and feet... As blood flows down the > legs from the body it meets with colder blood coming back up and the > warmth flows into the colder part of the foot." hmmm... the foot doesn't need particularly warm blood if it has anti-freeze. What a counter-current heat exchange system does is return the heat of the warm blood to the body core instead of losing it to the the water (~32 degrees F, 0 degrees C). In doing so the blood to the feet is cooled, so there's little warmth flowing into the colder part of the foot. Minimizing heat loss is what survival in cold climates is all about. Doug Herr Birdman of Sacramento http://www.wildlightphoto.com -------------------------------------------------------------------- mail2web LIVE ? Free email based on Microsoft? Exchange technology - http://link.mail2web.com/LIVE