Friday, 14 November 2014

Northern bald ibis

Geronticus eremita

Photo by Agustín Poovedano (Flickr)

Common name:
northern bald ibis (en); íbis-calva (pt); ibis chauve (fr); ibis eremita (es); waldrapp (de)

Order Ciconiiformes
Family Threskiornithidae

Historically, this species was probably found throughout North Africa and into the Middle East, but presently it is only found in two disjunct populations. There is a western population in Morocco, located in Souss-Massa National Park and nearby Tamri, and an eastern population in Turkey and Syria, of which possibly only a few individuals remain in a breeding area at Palmyra, in Syria. The western population is sedentary, while the eastern population migrates south to winter in central Ethiopia.

These birds are 70-80 cm long andhave a wingspan of 125-135 cm. They weigh 1,3-1,6 kg.

The northern bald ibis breeds in cliffs and escarpments in remote arid regions, often near the banks of rivers, along streams or on the coast. They forage in dry grasslands and scrublands, wetlands, pastures and stubble fields. They are present from sea level up to an altitude of 1.400 m.

They forage in large, loose flocks, mainly large invertebrates such as grasshoppers and locusts, crickets, beetles, earwigs, ants, woodlice, spiders, scorpions and molluscs, but also small vertebrates such as lizards, frogs, fish, rodents and birds.

Northern bald ibises breed in February-June. They nest in small colonies of 3 to about 40 pairs, each pair building a loose platform of branches lined with grass and placed on a cliff ledge or cave. The female lays 2-4 eggs, which are incubated by both parents for 24-28 days. The chicks are fed by both parents and remain near the nest until fledging, 43-47 days after hatching, but continue to be fed by the parents for quite some time afterwards. They reach sexual maturity at 3-5 years of age.

IUCN status - CR (Critically Endangered)
This species as a small breeding range and a global population estimated at just 200-250 individuals. The Syrian population is believed to be in decline, while the population in Morocco has been stable or slightly increasing since the 1980s. The species declined over several centuries partly owing to unidentified natural causes, but the more recent declines result of a combination of factors, namely illegal building and disturbance close to the breeding cliffs, changes in farming practices on the feeding grounds, hunting and habitat degradation through overgrazing and collecting of firewood. Conservation actions underway include captive breeding programmes, based on the many northern bald ibises that live in zoos worldwide, while the Souss-Massa National Park was designated specifically to protect nesting and feeding areas, and the provision of freshwater near the breeding colonies in the national park has been shown experimentally to increase productivity, buffering individuals against the impacts of low rainfall.

No comments:

Post a Comment