voyager

Q&A October 2007

Q Why don't penguins get cold or freeze when they swim in water that is very cold?
Submitted by 1st grade students in the "Only One Ocean" class, Birch Aquarium at Scripps Summer Learning Adventures Camp, La Jolla, Calif.

A There are a few special ways that penguins have adapted to stay warm in extremely cold water.

penguin In the water, penguins use muscles to flatten their feathers to form a watertight layer a bit like a raincoat.

First of all, penguins have an innermost layer of very soft downy feathers, similar to those of baby chicks, which helps trap heat close to their bodies.

Penguin outer or top feathers also are fairly stiff and packed tightly all over the penguin's body. In fact, they have more feathers per square inch than most other birds. In the water, penguins use muscles to flatten their feathers to form a watertight layer so no cold water can get through to their body. It works a bit like a raincoat.

Penguins must keep their feathers clean and waterproof to stay warm. They do this by preening. When penguins preen, they take oil from a gland on their backs and smooth it over their feathers. This helps waterproof the feathers. The oil repels the cold seawater and keeps their bodies dry.

penguins Penguins have a special layer of very soft feathers that traps heat close to their bodies.

Penguins can also control their blood flow so that their "core" body remains warm while other parts get cold. The core body is where all the important organs, such as the heart and brain, are located. Some penguins that live in cold places, like the big emperor penguin, have a layer of fat right under their skin that helps keep them warm as well.

Even with all of these adaptations, penguins can still get cold in the water. We frequently see them shivering a short while after they get back on land. People shiver when they are cold too. Shivering warms up our muscles, which helps to warm our whole body.

penguins Penguins have adapted to stay warm in extremely cold water, but sometimes even they get cold and shiver to warm up.

Cassondra Williams, graduate student, Center for Marine Biotechnology and Biomedicine

voyager

Scripps Scientists take on questions from students curious about ocean and earth sciences


cassandra williams

"Even with all of these adaptations, penguins can still get cold in the water."
— Cassondra Williams