Expert: Walter Hintz - 2/26/2009

Question
Hi! I learned this evening that bullfrogs do not sleep. I would like to know _why_ they don't sleep. I've searched online for an answer, and the information given -- that they estivate during dry periods and hibernate during cold periods -- really hasn't answered my question. I'd very much like to know what evolutionary advantage their not sleeping gives them. Thank you.  :)

Answer
Hi Erin
We have to define sleep.  To us it is a form of unconsciousness with eyes closed and a predominance of Delta brain waves with no activity. Sleeping in other animals is an entirely different.  In a frog it is a period of inactivity and slowed down metabolism.
Why questions are in the realm of evolutionary biology.  A from is food for a lot of predators.  The frog has to be aware of its surroundings at all times