Saturday, September 26, 2009

Do Penguins Get Cold?

Just the thought of an environment where temperatures may drop to as low as -95 degrees Fahrenheit is enough to make me throw on a sweater, turn up my heat, and brew myself a cup of hot chocolate. But for some species of penguins, that environment is home, and they don't even have scarves to put on, let alone sweaters. That being said, these feathered, flightless creatures beg the questions, "How do penguins keep from freezing to death?" and even so, "don't they ever get cold?"

It seems that there are actually several factors that keep penguins from freezing to death. The website Cool Antarctica explains that one reason they are able to survive the brutal cold is because of their size. Emperor Penguins can weigh as much as 66 pounds, and though they aren't huge animals, they are large enough to combat the cold. "The larger the animal, the smaller the surface-area to volume ratio," reads the website, "so the less relative area there is to lose heat." If this doesn't make sense, just think of a glass of water in the freezer. The more water in the cup, the longer it will take to freeze. The larger the animal, the longer it will take to cool down.

In addition to their size, Penguins have two built in features that come in very handy at below freezing temperatures. Firstly, a layer of fat under the surface of their skin. According to Cool Antarctica, this fat layer is like insulation for penguins and is especially crucial when the birds are in the water. "It keeps all warm blooded, cold water animals operational down to 25.8 degrees Fahrenheit," says the site. But surely Antarctic waters get much much colder than that. How do the penguins know to get out of the water before it drops below 25.8? Well, Cool Antarctic explains, "you can't get sea water colder than that without it being solid and then it would difficult for anything to swim in it!"

A second feature important to the survival of penguins in the cold are their feathers. Though they do little to protect penguins in the water, their feathers are extremely useful on land as both a second layer of insulation, and a way of drying off. "Penguin feathers aren't like the large flat feathers that flying birds have, they are short with an under-layer of fine woolly down," says Cool Antarctica. "Penguin feathers are also very good at shedding water when the bird emerges from the sea. They overlap and give a good streamlined effect in the water and excellent wind-shedding abilities when on the land," reads the site.

But surely Penguins get a little chilly sometimes, right? Yes, especially their feet, which don't have that warm layer of fat to protect them. Obviously, if their feet got too cold, they wouldn't be able to move them, which would lead to inactivity, and even bigger problems. However, Penguins have a built in mechanism to deal with that also. According to Cool Antarctica, the muscles that penguins use to operate their feet, are not actually in their feet, but rather in an area of the body that is protected by the penguin's fat layer and feathers. "This means that it doesn't matter if the feet and flippers get really cold as they can still be operated normally by regions that are fully functional and at normal body temperature," explains the site.