We've known for a long time that marine mammals (like whales and seals) communicate much the same way Bill does: with a series of weird series of grunts and whistles. Now, researchers say they also communicate by clapping!
To be sure, you may have seen seals clapping in a zoo or aquarium park. Those seals are trained to clap for our amusement. This is different.
There's a guy named Dr. Ben Burville who spent 17 years taking video of seals while diving. One of the things he caught on film were seals clapping their front flippers while completely underwater. And, the claps were LOUD! Which is weird because when you or I clap out hands, the sounds comes from air being compressed between our hands. But there's no air underwater to compress.
Scientists are still trying to figure out how the heck these seals can clap loudly underwater. But they have a strong idea of WHY they do it. Depending on the context, the seals are try to attract a mate or warn other males to back off.
Now that I think about it, I did attend a performance of Jersey Boys with Bill, and he clapped a lot. I'm not saying he looked exactly like a seal. But I'm not saying he didn't.
The research on seal clapping was published in the journal Marine Mammal Science.