STATE: What birds tell us about condition and change

Bas van Balen The Javan Hawk-eagle Spizaetus bartelsi is classified as Endangered Zoom In

Biodiversity is rapidly being eroded. Threatened species are becoming more threatened and many common ones are in decline. Many species are confined to small ranges or distinctive habitats, or congregate at particular sites. Threatened and geographically- concentrated species map out a network of key biodiversity areas within the wider landscape.

In many parts of the world, the familiar species around us are in decline. Some of these declines are very rapid and severe. Although most of these species are still relatively common, their declines highlight wider environmental problems.

Current extinction rates are exceptionally high. Without concerted action these rates will continue to rise. In total, 1,211 bird species (12% of the total) are globally threatened. Of these, 179 are now Critically Endangered.facing imminent extinction. Only for birds do we have comprehensive information on global trends over recent decades. The Red List Index for birds shows that they have become more threatened since 1988, with more species slipping closer to extinction. Seabirds and Asian forest birds have shown particularly severe declines.

Threatened species occur across the world, but they are concentrated in the tropics and especially in moist tropical forests. Many other species are geographically concentrated, and often confined to distinctive habitats. More than one-quarter of bird species have very small breeding ranges. Most of these occur together in places called 'Endemic Bird Areas — mainly in the tropics and subtropics — that cover just 5% of the Earth's land surface. A further 10% of bird species congregate in large numbers at a few special sites at particular times in their life cycles.

Species that are threatened and geographically concentrated can be used to locate key biodiversity areas.critical sites for conservation. For birds, over 7,500 Important Bird Areas (IBAs) have so far been identified in nearly 170 countries. They are crucial strongholds for maintaining species. overall ranges and populations, and a set of vital stepping stones for migrants. IBAs are also effective at conserving biodiversity other than birds.