Expert: Ed Saugstad - 10/23/2004

Question
A question arose with my wife about animals that yawn. We generally accept that most animals with lungs will yawn from time to time, but we than wondered if aquatic animals yawn. It seems I've seen pictures of seals yawning but they can come on land and do it at their leisure. But what about whales and other mammals that cannot "rest" on land. Do they yawn? I don't need the debatable reasons about the causes of yawning i.e. oxygen deprivation, social conditioning, just if they do it at all.
Thanks, Roger


Answer
Dear Roger – As you likely already are aware, researchers in the field of animal physiology state that all vertebrates yawn. As for underwater yawning, at least some aquatic animals (particularly fish) yawn under water. For some examples, see http://www.seafriends.org.nz/images/behavior.htm and http://www.minkewhale.org/minke_whale_video_clips.htm With fish, at least, yawning does appear related to oxygen levels in the water (see http://www.aquariumpros.com/faqpro/chemistry_2.shtml scroll to bottom).
Hope this helps,
Saugy