Mountains on islands are great for species diversity. I had never thought about that until I took a bus tour on Maui to the Haleakala Crater last month, going from near sea level to 10,000 ft. The driver/guide talked about how a species of bird might come to the island and descendants would fill various niches at different elevations, meanwhile plants and insects are doing the same thing. He said that if Darwin had visited that mountain, he would have forgotten about Galapagos. Exaggeration or no, that still speaks to great diversity. He also said that with such diversity of species, there is more rapid loss of species. He also mentioned that where birds and insects were essentially without predators that flight was too much of a luxury to hang on to.
