Heh. Otters are so much fun to watch. And as you can see from the last two pictures you posted, difficult to get a yawning shot of. There are a couple of zoos I go to that have otters, and it's nearly impossible to get good pictures of them when they're swimming around. They're simply too quick, always moving. But that does make it more of a challenge.
Thanks for posting up these finds. Always nice to see when others have been able to have better luck than I ever do.