Breeding ecology and behaviour of the last wild oriental Northern Bald Ibises (Geronticus eremita) in Syria

Abstract

A relict colony of Northern Bald Ibis (Geronticus eremita), a critically endangered species, was unexpectedly discovered in Syria in 2002. During six subsequent breeding seasons (2002–2007), the 3, and then 2, breeding pairs of Northern Bald Ibises have shown to be still vital and, when intensively protected, showed a higher average breeding success than that recorded in Morocco, the only other country where these birds still breed in the wild. During the six breeding seasons, a total of 24 chicks fledged and left the breeding area successfully. Between 2004 and 2007, a total of 5 immature ibises have made a return to the colony, separately and later than adults. As a consequence, two recruitment events have taken place (2006 and 2007), partly compensating for the gradual decrease in the number of adults. Breeding adults arrive from migration during the second half of February, separately, and leave together around mid-July. They nest in cavities and ledges of two limestone cliffs of the central Syria desert, located 20 km apart, well protected from the predominant wind. Breeding behaviour and the cycle are described, summarised and compared with data from the wild colonies of Morocco and the colony of Turkey before the extinction. Key threats still in place at the Syrian breeding quarters are human disturbance during settling and incubation, chick depredation by ravens, uncontrolled hunting and habitat degradation. Recommendations on how to enhance the breeding performance and ensure the survival of this colony in the future are given.