As far as we can tell, the Hawaiian tree snails evolved with no predators, so they never developed defense mechanisms. Hawaii Professor Emeritus Michael Hadfield More Quotes by Hawaii Professor Emeritus Michael Hadfield More Quotes From Hawaii Professor Emeritus Michael Hadfield They were the best known tree snails, big and pretty snails, once hyper abundant in the forest... of the island, there's no doubt that only 10 or so of those( species) still exist, and none of them will survive in the next 10 years. Hawaii Professor Emeritus Michael Hadfield us-news