Our photo of the day comes from Kananaskis, Canada.
Everybody yawns ... people, fish, snakes, and even marmots, as evidenced in this marvelous photo by Tony LePrieur. Yet while it appears that this member of the squirrel family with mouth agape is signalling its boredom, the reason we all yawn is still up for debate. One theory that has gained a lot of ground is that yawning helps regulate brain temperature. If that's the case, this seemingly non-impressed marmot must have a pretty cool brain.
Would you like to see your nature photo featured as the TreeHugger photo of the day? Join TreeHugger’s Reader Photo Pool on Flickr and add your pictures to the group. Alternatively, send it to email@example.com with "photo of the day" in the subject line.