Typically human-caused eradication of entire avian species
Bird extinction is the complete elimination of all species members under the taxonomic class, Aves. Out of all known bird species, (approximately 11,154), 159 (1.4%) have become extinct, with 226 (2%) being critically endangered.[1] There is a general consensus among ornithologists that if anthropogenic activities continue as current trends suggest, one-third of all bird species, and an even greater proportion of bird populations, will be rendered extinct by the end of the 21st century.[2]
For critically endangered species, scientists estimate they will face extinction in a few decades without proper conservation efforts; for some of these species, the current presence of extant populations is uncertain.[3]
^Ceballos, Gerardo; Ehrlich, Anne; Ehrlich, Paul R. (2015). The annihilation of nature: human extinction of birds and mammals. Baltimore: Johns Hopkins university press. ISBN978-1-4214-1718-9.