🚀 go-pugleaf

I was at the aquarium/oceanarium in Chicago last weekend, and noticed that
the two Beluga whales in a large tank were doing something rather strange.

They were just breaking the surface from underwater, collecting a small bit
of air, and blowing it under water into perfect rings (similar to smoke rings.)
After the rings spun and grew and moved a bit, the whales would swim down and
bite part of the ring, or try to swim through it, until it collapsed.  Then
they went back to the surface, and did it again.

A staff member there told me that the whales had just started this within the
last month, and the staff had no idea why they were doing it.

Is this common behaviour of whales in captivity, or in the wild?  Does it
serve a function?  Do other animals play in a manner similar to this?

Thanks for any information,
Dan
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Dan Katz                                                       dsk@nwu.edu
Dept. of Electrical Engineering                             1(708)491-8887
Northwestern University, Evanston, IL, 60208                E pur si muove