Hi Maureen they do occur in the wild, on Alcatraz Island. Not naturally. All 3 species were put there by the Seri Indians. You need to get the book, "Singing the Turtles to the Sea" by Gary Paul Nabhan. I picked a really nice used hard cover up on ebay for like 7 bucks shipped. It is a great book and I really think you would like it. It is one of my favorite books.