We have a lot of Penguins at Edinburgh Zoo – they avoid their feet getting too cold by hunching down so that their belly feathers cover their feet. They also rock back onto their heels and tail to lift their feet off the ice. Really interestingly they have a kind of heat exchanger to regulate their foot temperature; blood vessels which flow away from the feet are close to vessels running towards the feet, so just the right amount of heat can be transferred between them to keep the feet from freezing. If their feet were too warm, they would waste lots of energy. If they get too cold, the amount of warm blood flowing to the feet can also be increased by widening the diameter of the arteries running to the feet. This is called vaso-dilation. Fascinating – thanks for the question <(") – this is meant to be a penguin!!
Antarctic birds and mammals such as penguins, whales and seals, are warm blooded animals and they maintain similar internal body temperatures similar to warm blooded animals in any other climate zone – that is about 35-42 C. They have to keep high body temperatures to remain active.
The system that stops a penguin’s foot from freezing is very elaborate and sophisticated and employs two mechanisms. The first one allows the penguin to control the rate of blood flowing to its feet by varying the diameter of arterial vessels supplying the blood. In cold conditions the flow is reduced, when it is warm the flow increases.
The second mechanism takes the form of ‘counter current heat exchangers’ at the top of the legs. The arteries, which supply warm blood and oxygen to the penguin’s feet break up into many small vessels which are closely linked to similar numbers of venous vessels bringing cold blood back from the feet.
Or like in Happy Feet by dancing their socks off 🙂 I love that movie!!
Good answers from Gill and Akram… i’ll also add that the penguins use their amazing feet very cleverly to protect their eggs! They keep their eggs warm by storing them on top of their feet, underneath some of their warm feathers 🙂
Great answers from everybody. Along with everything else mentioned, penguins’ feet are also very well insulated. They need to be!!!!! I don’t even like walking bare foot on the tiles in my kitchen………..