State of the world's birds

The historical and current relationship between numbers of restricted-range species and the area that they occupy

Stattersfield et al. (1998)

A ‘species/area’ curve of the numbers of restricted-range landbirds and the area that they occupy shows that, historically, the 2,451 restricted-range species that are endemic to the 218 EBAs (c.25% of all species), were confined to c.14.5 million km² (c.10% of the world’s land area), while 2,000 (c.20%) were confined to c.4 million km² (c.2%). Today, the same restricted-range species are present in only c.7.3 million km² of remaining natural habitat (c.5% of the world’s land area; approximately the size of Australia) and c.20% occur in a total of less than 2 million km² (c.1%) (Stattersfield et al. 1998; see figure). These findings show that focusing conservation resources and actions within a relatively small area can help to achieve the conservation of a major part of the Earth’s terrestrial biodiversity.