Extinction risk assessment for birds through quantitative criteria

The system used for classifying species according to their risk of extinction in international Red Lists is currently being revised by the International Union for Conservation of Nature. The proposed system is based around a set of quantitative criteria and aims to provide a more explicit and objective method that can be applied across a wide variety of living forms. The first major application has been in the preparation of a new edition of Birds to Watch, a summary of threatened bird species at a global level, by BirdLife International. An analysis of the classification of bird species in this publication indicates that the proportion of birds thought to be threatened varies across regions from about 14% in New Zealand and 12% in Africa down to only 3% in Europe. There are some significant differences among regions in the kinds of criteria that lead to threatened listing, with continuing or expected declines in numbers or habitat being especially significant in Africa and Europe.