How do penguins stay warm?

The very reason for my being in Antarctica isn't to take helicopter or airplane rides to remote locations. There's more to Antarctica than fixing antiquated machinery and having unique experiences. The reason we're all really here is the pursuit of knowledge. At the very heart of this pursuit is scientific research. Every discipline of science is represented here in one way or another. The ozone hole, the ocean, glaciers, rocks, meteors, ice cores, seals, fish and tiny invisible particles are all studied here with equal fervor. It's easy to forget that our main purpose here isn't to support ourselves, but rather to support this pursuit of knowledge. On the all-star line up of things being studied are penguins. They are an ideal icon for the research being done in Antarctica. They're cute, photogenic and truly representative of this special place. There are many species of penguins in the world but the most well known ones are closely associated with extremely cold environments. Humans can benefit greatly by learning how penguins survive in these extreme conditions.

So how do they do it? How can penguins survive in the brutal conditions that Antarctica dishes out? Here's what scientists have discovered about penguins: First, they have feathers. Feathers are an effective insulator. Penguin feathers aren't like feathers on other birds. Rather than being large and flat, they're short with a fine woolly, downy under-layer. Also, they overlap and give a streamlined effect in the water and have excellent wind shedding capabilities on land. Penguins can fluff their feathers when it gets extremely cold, thereby trapping more warm air and increasing their insulation. The feathers also are very effective at shedding water when the bird emerges from the water.

Feathers are great on land, but penguins spend more time in the water than they do on land so they need additional protection. Mother nature's best internal insulator is fat. Blubber keeps all warm blooded, cold water mammals operational at temperatures as cold as 25.8 degrees F (the freezing temperature of sea water).

Size also plays an important role in heat retention. The larger something is, the less surface area it will have in relation to it volume. Think of a shot glass for example. A shot glass contains a lot of glass for relatively small portion of liquid. A beer glass on the other hand holds much more liquid in relation to the amount of glass. The math goes something like this (using cubes instead of glasses):

A 1 inch cube:

Volume is 1"x1"x1" = 1 cubic inch
and the surface area is equal to 6 faces of 1 inch x 1 inch so 6 x(1x1) = 6 square inches so for every 1 cubic inch of volume, there is 6 square inches of surface area from which to lose heat.

A 3 inch cube:

Volume is 3" x 3" x 3" = 27 cubic inches
the surface area is equal to 6 faces of 3 inches x 3 inches or 6 x(3x3) or 54 square inches which is only twice the volume so that for every inch of volume, there are only 2 square inches of surface area from which to lose heat.

The take home message is that a larger body will retain more heat.

Body design also plays a key role in heat retention. Penguins flippers and feet have a lot of surface area and are subject to great amounts of heat loss, but the muscles that control these appendages are located more closely to the core of the animal. The muscles control the feet and flippers through a complex array of tendons (kind of like a marionette), minimizing blood flow and heat loss to the feet and flippers.

Besides individual mechanisms, penguins also have social mechanisms to aid their survival. They huddle together to stay warm. It's an extension of the larger body idea. Scientific calculations estimate that emperor burn half as much body fat by huddling than they would if they remained solitary. This enables them to survive the entire winter without eating.

Cuteness doesn't generate heat