Body size
Wingspan
Weight
Lifespan
The Northern Bald Ibis
(Geronticus eremita)
As is typical for ibises, the Northern Bald Ibis has a long, downward-curved beak. Its black, greenish-iridescent plumage and bald, red-colored head with individual black markings are characteristic features. This bare head is framed by long crest feathers, which the birds can raise when excited and can serve as indicators of their mood. Juvenile birds are easily recognized by their grey-feathered heads and the absence of the crest. The sheen of their plumage also only develops upon reaching sexual maturity. The red beak and strong red legs create a striking contrast to their dark plumage. Males and females do not show obvious differences in appearance, therefore there is no sexual dimorphism
Diet and Habitat:
Northern Bald Ibises forage using their sense of touch, probing the soil with their beaks to find insect larvae, earthworms, and other invertebrates. Their long, slender beak serves as an ideal tool for this purpose. During the day, the birds often seek out open areas such as short-grass meadows and pastures, and they are also known to forage on golf courses and other sports grounds. For this reason, they can be considered cultural followers (species that benefit from human-altered landscapes). The bald head of the Northern Bald Ibis resembles that of a vulture and is often the reason for the mistaken belief that it, too, is a scavenger.
Behaviour and Reproduction:
The Northern Bald Ibis is a social bird, and it is reported that historic colonies once consisted of several thousand individuals. Paired birds often greet each other with an elaborate ritual, during which they raise their crest feathers and bow to one another while making the characteristic slurping “chrrupp” sound. This ritualized behaviour often triggers imitation across the entire colony, making the birds audible from a distance.
Northern Bald Ibises are usually only seasonally monogamous: the pair bonds formed during the breeding season can change from year to year. However, some pairs do stay together for many years. During breeding, they form a close team, with both parents equally involved in nest building, incubation, and raising the chicks.
For nesting, the birds prefer steep cliff faces with numerous crevices. These offer protection from harsh weather and keep many predators away. Northern Bald Ibises lay up to four greenish eggs, similar in shape and size to chicken eggs. Typically, the female lays one egg every two days and begins incubating as soon as the first egg is laid. As a result, the chicks hatch in staggered intervals, usually two days apart, which establishes a hierarchy in the nest based on age.
The nestlings fledge after 42 to 50 days. They then accompany their parents in search of food and later often form juvenile groups with peers. Driven by an innate migratory instinct, they follow experienced conspecifics to the wintering grounds in autumn and, in doing so, learn the migration route.
