Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The flora and fauna of Bermuda forms part of a unique ecosystem thanks to Bermuda's isolation from the mainland of North America. There are a wide range of endemic species and the islands form a distinct ecoregion. Bermuda's wildlife is limited to those species which were able to fly to the island or were carried by winds and currents. This has resulted in some groups such as mammals being poorly represented. Once on the island, organisms had to adapt to local conditions such as the climate, lack of fresh water, frequent storms and salt spray. The islands shrank as water levels rose at the end of the Pleistocene epoch and fewer species were able to survive in the reduced land-area. Today the variety of species on Bermuda has been greatly increased by introductions, both deliberate and accidental. Many of these introduced species now pose a threat to the native flora and fauna.