The particularities of the natural environment of the islands and mainly of their fauna and flora are numerous and frequently have a significant scientific interest. A basic reason that explains why the islands are in the scope of scientists and nature friends’ interest, is their long-term isolation from other populations that has resulted in the creation of endemic forms that do not exist elsewhere and present peculiarities which are worthwhile to observe and study.

The relatively "close" Aegean Sea and the proximity of most Aegean islands to the continental coast, are the reasons that we do not meet endemic bird species. Nevertheless, as Tilos is the most isolated island from its neighbors, endemic forms of mammals evolved during the historical times (as the dwarf elephants)