The small genus Geronticus belongs to the ibis subfamily (Threskiornithinae). In reference to the bald head of these dark-plumaged birds; in English they are called bald ibises. Geronticus contains two living species. The Northern Bald Ibis (G. eremita) has a neck crest of elongated feathers. It is a Critically Endangered species found around the Mediterranean. Its range had expanded after the last glacial to Alps of Germany and even a bit further north, but it was rendered extinct there mainly due to habitat destruction and unsustainable hunting. The Southern Bald Ibis (G. calvus) whith a red crown patch but no crest is classified as Vulnerable and found in subtropical southern Africa. What appears to be an ancestral form, Geronticus balcanicus, was found in a Late Pliocene deposit near Slivnitsa (Bulgaria), which are almost alike those of living bald ibises. About 2 million years ago these birds were entirely indistinguishable from the modern Northern Bald Ibis inhabited at least Spain, if not the whole western Mediterranean region already. Thus, the extinct species may be the immediate ancestor of G. eremita, which would have originated at the western extent of its range. Some authors even include the Bulgarian population in G. eremita, but most are more cautious. G. balcanicus may also represent a less directly related lineage which inhabited the inland regions northeastwards of the European Alpides and, like the immediate ancestor of G. eremita in this scenario, became isolated from the ancestors of G. calvus when gene flow across tropical Africa ceased. Geronticus perplexus is by far older, and known only from a piece of distal right humerus, found at Sansan (France) in Middle Miocene rocks. It was initially considered to be a heron and placed in the genera Ardea and Proardea. More plesiomorphic than the living species, it seems to represent an ancient member of the Geronticus lineage, in line with the theory that most living ibis genera seem to have evolved before 15 million years ago. Geronticus apelex is apparently the direct ancestor of the Southern Bald Ibis. Its remains were found in Early Pliocene deposits near Langebaanweg (South Africa) which date back about 5 million years.
|wingspan min.:||125||cm||wingspan max.:||135||cm|
|size min.:||70||cm||size max.:||80||cm|
|incubation min.:||24||days||incubation max.:||25||days|
|fledging min.:||40||days||fledging max.:||25||days|
24-25 days. Young Fledge after 40-50 days.
Usually feeds in small, loose flocks.
Video Northern Bald Ibis
copyright: J. del Hoyo
Geronticus eremita breeds mostly outside Europe in Morocco and (to a lesser extent)
Syria, but a tiny breeding population of 15 pairs also persists at Birecik in Turkey.
Although this population underwent a large decline between 1970-1990, it was stable
during 1990-2000. Nevertheless, as a consequence of the tiny size of its European
population, this globally threatened species is evaluated as Critically Endangered in
Until recently Geronticus eremita was believed to survive only in Morocco at Souss-Massa National Park (338 km2; three colonies) and at nearby Tamri (one colony, almost half the breeding population), with some movement of birds between these two sites. There are reports of it in Mauritania as a non-breeder. A colony of three pairs and one adult was recently discovered in Talila, Syria; and further breeding colonies may exist across the Syrian Steppe, although searches in 2003 proved fruitless. A further colony exists at Birecik, Turkey, but is now heavily managed; with birds taken into captivity after the breeding season to prevent them from migrating. It is thought that birds used to winter in Sudan, Eritrea, Ethiopia, and perhaps Somalia, Saudi Arabia and Yemen, with the most recent wintering record being of three adults in February 1997 in the Massawa area of Eritrea. Post-1989 records in Saudi Arabia and Eritrea suggested that an undiscovered breeding colony remained in the Middle East, which has now been confirmed by the discoveries in Syria. In 1994, the Moroccan population was estimated at 300 individuals (59 breeding pairs). In 1998, it had declined to c.200 birds, following the mysterious death of 40 birds in 1996. In 1999, the population had increased slightly, and by 2006 there were around 277 adult birds, of which 102 pairs made nests (92 pairs laid eggs). Importantly, since 1980 there has been no overall decline in numbers at Souss-Massa NP. Growing numbers, and good productivity in recent years (over 500 birds in the Moroccan population after the breeding season in recent years) gives cause for optimism that former colonies may soon be recolonised. The Turkish population now numbers 86, and is expected to rise to 100 in 2006. The Syrian population has suffered a severe population decline in the past 30 years, and numbered just five adults in 2005. Captive bred populations exist at Grunau, Austria (22 birds, now breeding), and another is planned in Fagagna, Italy.