2006-10-05 14:20:51 · 11 answers · asked by Steve C 2 in Science & Mathematics ➔ Zoology
Penguins have a "core" body temperature of between 39 and 40°C. However, their extremities (feet, etc.) can be considerably cooler. In the Antarctic penguins the ability to keep different parts of their bodies at different temperatures contributes to their survival in the extreme cold.
2006-10-05 14:24:06 · answer #1 · answered by SCSA 5 · 1⤊ 1⤋
The short answer is that birds have a mechanism in their legs known as "counter-current circulation". This allows their bodies to stay warm without losing too much body heat to the colder environment.
The average body temperature of a bird is close (if not a bit higher) than that of mammals. When blood is pumped from the heart to the rest of the body, the blood is at body temperature. There is a danger, however, that when the blood reaches the feet, most of the body heat that the blood is carrying will be transferred out to the colder air. If this were allowed to continue, the animal would eventually freeze to death (or, it would have to expend a *lot* of metabolic energy just to keep warm).
How birds, such as penguins, prevent this is by transferring their body heat from an artery (which is bringing the warmed blood to the feet) to a vein (which brings the warmed blood back to the body). This allows the blood to reach the feet and oxygenate the tissues, but reduces the amount of body heat lost to the environment. In this manner, the animal can stay warm.
How is heat transferred from an artery to a vein? The artery bringing blood down the legs to the toes is literally surrounded by a number of veins. The blood in the veins is cooler than the blood in the arteries, so a thermal gradient is established, allowing the heat to be transferred via convection (convection = physical transfer of heat). The temperature of the blood at the bird's foot is considerably lower than the temperature of the blood back near the heart; but it is still above freezing temperatures.
Why this isn't uncomfortable for a bird, I don't know, but there you go!
Hope that helps!
2006-10-09 02:34:01 · answer #2 · answered by red_iguana27 2 · 0⤊ 0⤋
The first answer is correct, many animals in particular mammals that live in very cold climates such as wolves and probably penguins have what is called a 'rete mirable' (spelling may be off?) a network of blood vessels which shunts warm core blood laterally across a limb (leg) before the blood is cooled towards the base of the limb, thereby maintaining the animals core temperature.
2006-10-05 14:44:00 · answer #3 · answered by gnypetoscincus 3 · 1⤊ 1⤋
They are like alot of other birds who live and work in freezing weather. I raised chickens when I was a kid, and there feet would never freeze. After closer observation, it the structure of there lower leg, they have miminal blood circulation in their feet and toes, it is mostly tendons, and ligaments. The muscle portion of there leg and "foot" is insulated with feathers or body fat. The toes and feet have very little fluid in their foot that exposed to below freezing weather (ie no circulation other than one small vein which closes when it gets cold). And even though I am sure there toes do get below freezing temperature, there is not enough fluid in them to freeze up due to lack of fluid in them to freeze.
2006-10-05 16:44:40 · answer #4 · answered by David T 2 · 1⤊ 1⤋
Never mind their feet... imagine that you are a male penguin with legs as short as that on the ice!
2006-10-05 14:38:40 · answer #5 · answered by A Teesside Smart**** 3 · 1⤊ 1⤋
There is a sort of "anti-freeze" chemical that naturally occurs in lots of birds' feet that keeps blood circulation and everything else in their feet working well.
2006-10-05 14:30:15 · answer #6 · answered by songbird 6 · 1⤊ 1⤋
the penguins feet are made from insulator skin which it reduces the loss of heat from body to environment. the skin is one of the thermoregulatory adaptation where its contain nerves, blood vessels(to increasing the transfer of body heat) and consists of 3 layers(epidermis,hypodermis and dermis). the hypodermis contain thick adipose tissue (fat) and blood vessel.Their stiff feathers also serve as insulation, and are waterproof when oiled.
2006-10-06 04:53:20 · answer #7 · answered by meowpinkly 2 · 0⤊ 0⤋
Interesting question and I do not think any of the replies so far makes sense.
How does the blood in the feed remain liquid and flowing, when exposed to -40C for hours on end? Even pure car antifreeze would struggle to remain liquid under those conditions.
2006-10-05 16:09:22 · answer #8 · answered by Anonymous · 1⤊ 1⤋
Why don't they die of heat exhaustion in the Summer, in all those zoos. The parts that they're kept in aren't cold.
2006-10-05 23:18:58 · answer #9 · answered by gr_bateman 4 · 0⤊ 0⤋
they have special little penguin socks, extra thick of course.
2006-10-05 16:34:52 · answer #10 · answered by frankiethebear2002 2 · 1⤊ 1⤋