Individual study: Captive breeding and releases of bald ibis Geronticus eremita fail to halt the decline of a wild colony at Birecik, Sanliurfa Province, Turkey
Akçakaya H.R. (1990) Bald ibis Geronticus eremita population in Turkey: an evaluation of the captive breeding project for reintroduction. Biological Conservation, 51, 225-237
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Release captive-bred individuals into the wild to restore or augment wild populations of storks and ibises
A replicated study in southeast Turkey in 1977-88 (Akçakaya 1990) found that northern bald ibis Geronticus eremita bred or kept in captivity did not increase the Turkish population. From 1981-88, 67 individuals were released and 12 (18%) migrated with the wild population (note: this excludes 1984, 1986 and 1987, for which data were not available). There was high winter mortality among birds that did not migrate and also high mortality on migration. The wild population in the study area declined over the study period, with five pairs in 1986, seven in 1987 and only four birds returning in 1988. This study is also described in ‘Use captive breeding to increase or maintain populations’ and ‘Provide artificial nesting sites’.
Provide artificial nesting sites for ibises and flamingos
A study in southeast Turkey in 1977-88 (Akçakaya 1990) found that a northern bald ibis Geronticus eremite population moved from a breeding site threatened by development to an artificial breeding site provided 3 km away within an artificial breeding station (discussed in ‘Use captive breeding to increase or maintain populations’) and consisting of wooden ledges approximately 20 m away from where captive birds were. This study is also described in ‘Release captive-bred individuals’.
Use captive breeding to increase or maintain populations of storks and ibises
A study in southeast Turkey in 1977-88 (Akçakaya 1990) found that efforts to breed northern bald ibis (waldrapp) Geronticus eremita in captivity were not very successful. From a captive population of between 11 and 45 individuals (with 41 taken from the wild over the study period), a maximum of 19 young/year were produced, with a total of 90 over the study period. This was equivalent to 1.45 young/nest, lower than in wild birds, possibly due to high levels of pre-fledging mortality due overcrowding in the cages. Forty-six young were healthy and 67 individuals were released. Post-release survival is discussed in ‘Release captive-bred individuals’ and this study is also described in ‘Provide artificial nesting sites’.