24-h behavioral sleep profile in a giraffe

A main sleep period occurs between 20-7 h.

On some days "Hans", a 2.2-year old male giraffe takes a nap in the early afternoon.

Note: the rare and short occurence of paradoxical sleep (PS).

W: waking
WR: waking recumbent
SS: standing sleep
RS: recumbent sleep
PS: paradoxical sleep

Ref.: Tobler & Schwierin (1996)