Birds are used extensively by people: over 40% of living species are used, primarily for pets (37%) and food (14%), but also for sport hunting, wearing apparel or ornamentation and traditional medicine. Red List Indices show that the overall status of these utilised species is deteriorating, with the number of species improving in status substantially outweighed by the number declining. Various factors drive these declines, including unsustainable use, but non-use factors combined were more important overall.
Birds are used extensively by people. A recent study (Butchart 2008) found evidence of use for 4,561 bird species, representing 45.7% of the world’s 9,990 extant and extinct bird species. Among these, two purposes of use dominate: 3,649 species (37.0% of extant species, 87.4% of utilised species) were recorded as being used as pets, and 1,398 species (14.2% of extant species; 33.5% of utilised species) were recorded as being hunted for food. Less significant uses include sport hunting, wearing apparel or ornamentation and traditional medicine.
Red List Indices for utilised species shows that they have deteriorated in status during 1988–2004 (Butchart 2008). Although some species have been downlisted to lower categories of threat owing to successful reduction in over-exploitation and other types of conservation action, many more have been uplisted to higher categories of threat owing to increasing threats, including overexploitation, driving faster population declines and leading to smaller population and range sizes. The Red List Index shows that the net effect of these up- and down-listings has been an overall reduction in the proportion of species expected to remain extant in the absence of additional conservation action, i.e. that this set of species is slipping further towards extinction.
Various factors drive these trends in the status of utilised species. Red List Indices (see figure) show that trends driven by use were outweighed by non-use factors combined. The pet trade and hunting for food drove similar rates of decline, but were outweighed by trends driven by other factors combined even when incorporating trends for which the use was a contributory factor as opposed to a primary driver.
Related Case Studies in other sections
BirdLife International (2008) The Red List Index for utilised bird species illustrates their deterioration in status. Presented as part of the BirdLife State of the world's birds website. Available from: http://birdlife.org/datazone/sowb/casestudy/161. Checked: 28/11/2015
|Key message: Overexploitation has already caused extinctions and remains a significant threat today|