The Bahamas, the Commonwealth nation of hundreds of islands roughly the size of Connecticut and with population of just a bit over Anaheim, is known for its crystal waters and pristine beaches—and its swimming pigs.
It is unclear when the pigs first appeared on Exuma Island or where they come from. There’s talk about a (daring) escape from a shipwreck, or sailors releasing the swine on purpose. In all probability, there were no pigs on this tropical paradise before European settlers came, so their mere presence is the work of human. The intriguing feat of nature, however, is that this population of pigs developed a fine aptitude for swimming.

Water's good today. Lisa Larsen/Public Domain/CC0 1.0