 According to evolutionary biologist E. O. Wilson, bird species that are endemic to islands face a greater risk of extinction—40 times greater than on the continents.At least 255 island bird species have become extinct since the appearance of humans, with 158 lost during prehistory and 97 lost between 1600 and 1994.In comparison, between 17 and 20 species of continental birds became extinct between 1600 and 1994.