The extent of extinctions of mammals on islands

Many of the world's oceanic and oceanic-like islands possessed endemic mamm al faunas before they were colonized by humans. These faunas, unbalanced an d impoverished compared to continental faunas, usually lacked large mammali an carnivores. In virtually all cases, the arrival of humans and their dome sticants and commensals on these islands is related to the extirpation of l arge numbers of endemic insular mammals. These extinction events affected a t least 27% of autochthonous mammal species on the world's oceanic and ocea nic-like islands. This percentage rises the 35% when volant mammals are exc luded. This reduction in the natural biodiversity brought about the disappe arance of several unique biological types that apparently never existed on the continents.