How many birds have gone extinct?
A total of 133 species are documented as having gone extinct since 1500. A further four species are now extinct in the wild and survive only in captive populations. Although extinctions have been better documented in birds than any other group of organisms, these totals are likely to be underestimates because extinction is difficult to document. A number of other species currently categorised as Critically Endangered have probably gone extinct too, but cannot be designated as such until we are certain. Fifteen such species are categorised as Critically Endangered (Possibly Extinct) or Critically Endangered (Possibly Extinct in the Wild). Thus, a total of 152 species may have been lost in the last 500 years.
