And let’s not forget about Bigfoot. According to The Learning Channel*, they are all over the US!!
*Or is that Animal Planet?
Right: it’s no surprise there are no native primates on Hawaii, or mammals. There are damn few reptiles (maybe none). [cite]
In addition to being very isolated islands, they’re also very young. The oldest of the principal chain is Kauai, which is only 5 million years old. A surprising number of animals wind up on islands or make it across seas on rafts of debris (imagine a hurricane or tsunami washing rafts of trees out to sea with animals clinging to them, those animals normally doomed but in a few lucky cases arriving on a fertile island!)
But 5 million years isn’t a lot of time for this to have happened, especially for such isolated islands.