Micro‑bubbles released underwater from the plumage of the emperor penguin reduce drag by creating a lubrication layer around its body.

The Emperor penguin has a unique strategy for exiting the ocean – one that enables it to launch from the water and land one to two meters away on an icy ledge. The penguin is able to “torpedo” in such a fashion because air lubrication increases its swimming speed prior to jumping from the water.

Before exiting the water, the penguin swims at the surface, where it is believed that it loads its dense coat of feathers with air via grooming. The bird then dives to a depth of 15 to 20 meters. During this dive or at the bottom, it depresses its feathers, thereby creating less space for the air to be stored and releasing micro-bubbles. Throughout its ascension, the penguin releases these bubbles in a controlled way, creating a layer of micro-bubbles over most of its body surface. This lubrication layer reduces drag, enabling the penguin to swim faster and to overcome gravity so that it can successfully launch from the water.

Check out this National Geographic video to see this penguin strategy in action:

https://youtu.be/A9mbCNs47FI

And check out this AskNature Nugget for a high-level overview of the strategy:

https://vimeo.com/75823228

This summary was contributed by Ashley Meyers

Last Updated October 13, 2016