Eighty two percent of threatened birds are declining; and in over a third of species declines are rapid (over 30% in 10 years or three generations). Twenty-five species, including the Spoon-billed Sandpiper Eurynorhynchus pygmeus have declined by over 80% over the past 10 years or three generations.
Most threatened birds have declining populations: in total 1,033 species (82% of threatened species) are declining, and 455 (36%) qualify as threatened because the declines exceed 30% in 10 years or three generations (whichever is longer). Twenty-five species are estimated or inferred to have declines that exceed 80% in 10 years or three generations. For example, since the 1960s the population of the formerly common Mariana Crow Corvus kubaryi has become functionally extinct on Guam despite a reintroduction effort (G. Wiles in litt. 1999; G. Rodda in litt. 2007). On Rota, it was thought to be stable, estimated at 1,318 birds in 1982, but has since declined to c.50 confirmed pairs in 2007 (G. Wiles in litt. 2007). Similarly, surveys on the breeding grounds of Spoon-billed Sandpiper Eurynorhynchus pygmeus show that the species has declined extremely rapidly from an estimated 2,000–2,800 pairs in the 1970s to perhaps fewer than 100 pairs in 2007 (E. Syroechkovskiy in litt. 2007). Only 103 species (9% of those with estimates) have stable populations, and just 50 (4%) have increasing populations, almost all in response to conservation efforts (e.g. St Lucia Parrot Amazona versicolor and Mauritius Kestrel Falco punctatus).
Compiled 2004, updated 2008, 2011
BirdLife International (2011) Most threatened birds are declining, some catastrophically. Presented as part of the BirdLife State of the world's birds website. Available from: http://birdlife.org/datazone/sowb/casestudy/108. Checked: 09/10/2015
|Key message: One in eight of the world's birds faces extinction|