Mallard

Description:

A pair of sleeping mallards. Ducks usually sleep with their head turned around backwards and nestled into their feathers, to keep their bill warm. Mallards are also often seen sleeping with one eye open. Find out more in the notes!

Habitat:

The shores of a large Central European lake.

Notes:

Mallards are often seen sleeping with one eye open.This is known as unihemispheric slow-wave sleep (USWS), and refers to the ability to shut down one half of the brain while the other half remains alert. USWS offers the advantage of being able to rest while keeping a eye on predators. Mallards can sleep with both eyes closed, but will increase USWS in areas of high predatory risk. Mallards at the edge of a sleeping group will spend more time in UNSW and keep watch for the others, a phenomenon a known as "group edge effect" . On the last shot both male and female have now shut their right eye.