An endemic species is a species that exists naturally in only one geographical location or region, ranging from a single pond or forest to an entire island or continent. The range is typically limited by the physical environment in some way, such as by mountains, an ocean, a desert, a type of soil, or the climate. It can also be limited by the biota, such as requiring a particular type of plant or animal as food. Endemic species occur more in some regions than in others, and are particularly common in isolated environments such as the Hawaiian Islands, Australia, and parts of the Amazon rainforest.
Endemic species are important for several reasons. One is that they often play a role in the local ecosystem, and thus the loss of one such species can endanger or lead to the extinction of other species. Another is that many species may eventually have potential for being used to produce new medicines or other beneficial substances, and once such species have vanished, the possibility for their use is lost forever. For example, it is possible that some rare marine animals and tropical plants may have potential for use in making medicines for difficult-to-treat diseases.
Because of their limited ranges, endemic species are particularly vulnerable to extinction from natural causes and/or human activity, including climate change, habitat destruction, the introduction of invasive species, and poaching.