This process is known as adaptive radiation and has produced many strange varieties of common mainland species. Some island-hopped to neighboring islands and developed into distinct populations and subspecies on each island. Others evolved into new forms to exploit each vacant niche that was available on a particular island. The most famous examples of this are the honeycreepers, of which there are over 45 varieties on the islands, and the estimated 700+ species of fruit flies, all unique and found nowhere else (Wilcove 1999). In all, Hawaii has 35 native bird species (reduced from an estimated 140 species before humans arrived) and over 5000 native insects (Wilson 2002, Pimentel et al. 2000). Most native plants are also unique and found nowhere else, including 96% of the flowering plants and 65% of the ferns (Wilcove 1999). .
Hawaii still has an exceptional array of wildlife, but it pales in comparison to what the islands once offered. Polynesians first arrived in Hawaii about 1,500 years ago (Royte 1995), bringing with them pigs, chickens, dogs, and unintentionally, Pacific rats (Rattus exulans). By the time Captain Cook became the first European to visit the islands in 1778, the coasts of all the major islands were cleared and settled for agriculture, and political and economic systems were in place (Burney 2001). Just as it has become clear that Native Americans did not live entirely "in harmony- with nature prior to European settlement, it is clear that native Hawaiians did not live in harmony with their surroundings. In fact, they contributed to far more ecological damage because Hawaii was and still is so fragile. Discoveries of fossil bones in sink holes and caves indicate that at least half, and possibly over two-thirds of Hawaii's land birds went extinct between the time the Polynesians arrived and when Cook arrived. The Polynesians and the animals they brought with them probably hunted the large flightless birds, including two species of ibis and seven geese species, to extinction.
