Hermit ibis, Waldrapp
The northern bald ibis, hermit ibis, or waldrapp (Geronticus eremita ) is a migratory bird found in barren, semi-desert or rocky habitats, often close to running water. This 70–80 cm (28–31 in) glossy black ibis, which, unlike many members of the ibis family, is non-wading, has an unfeathered red face and head, and a long, curved red bill. It breeds colonially on coastal or mountain cliff ledges, where it typically lays two to three eggs in a stick nest, and feeds on lizards, insects, and other small animals.
The northern bald ibis was once widespread across the Middle East, northern Africa, southern and central Europe, with a fossil record dating back at least 1.8 million years. It disappeared from Europe over 300 years ago, although reintroduction programs in the region are underway. In 2019 there were about 700 wild birds remaining in southern Morocco, and fewer than 10 in Syria, where it was rediscovered in 2002 but where their number declined in the following years, maybe to zero.
To combat these low numbers, reintroduction programs have been instituted internationally in recent times, with a semi-wild breeding colony in Turkey which counted almost 250 birds in 2018 as well as sites in Austria, Italy, Spain, and northern Morocco. These programs and the natural growth in Morocco from about 200 birds in the 1990s helped to downlist the northern bald ibis from Critically Endangered to Endangered on the IUCN Red List in 2018. There are about 2000 northern bald ibises living in captivity.
The reasons for the species' long-term decline are unclear, but hunting, loss of foraging habitat, and pesticide poisoning have been implicated in the rapid loss of colonies in recent decades.
According to local legend in the Birecik area, the northern bald ibis was one of the first birds that Noah released from the Ark as a symbol of fertility, and a lingering religious sentiment in Turkey helped the colonies there to survive long after the demise of the species in Europe, as described above.
This ibis was revered as a holy bird and a symbol of brilliance and splendour in Ancient Egypt, where, together with the sacred ibis, it was regarded as an embodiment of Thoth, scribe of the gods, who was usually depicted with a man's body and the head of an ibis. The Old Egyptian word akh, "to be resplendent, to shine", was denoted in hieroglyphs by a bald ibis, presumably as a reference to its glossy plumage. In a more abstract sense, akh stood for excellence, glory, honour, and virtue. It has also been used to signify the soul or spirit, one of five elements constituting personality.
Herodotus wrote of the man-eating Stymphalian birds, which had wings of brass and sharp metallic feathers they could fire at their victims. Ridding Lake Stymphalia in Arcadia of these creatures was one of the twelve labours of Heracles. These mythical birds are sometimes considered to be based on the northern bald ibis, but since they were described as marsh birds, and usually depicted without crests, the legendary species is more likely to be derived from the sacred ibis. Some depictions, such as the 6th-century BC Athenian black-figure amphora in the British Museum, clearly show the black head and white body of the sacred ibis. After the bald ibis became extinct in Central Europe, some later writers thought that Gesner's description was one of several in his book depicting mythical creatures.
The bird painted in 1490 in one of the Gothic frescoes in the Holy Trinity Church in Hrastovlje (now southwestern Slovenia) in the Karst by John of Kastav was most probably the northern bald ibis. A small illustration of the northern bald ibis is found in the illuminated St Galler Handschrift of 1562, a drawing by Joris Hoefnagel in Missale Romanum (1582-1590) and in paintings in the collection of Rudolf II at Vienna. It is believed that it had also been depicted at other places in Istria and Dalmatia, where it was presumably native during the Middle Ages, e.g. in the local church in Gradišče pri Divači and in the coat of arms of the noble family Elio from Koper. The portal of Lukovec Castle in Lukovica pri Brezovici (central Slovenia) also features this species.
In Birecik, Turkey an ancient celebration 'Kelaynak yortusu' held in mid-February to mark the return of the birds from Africa was revived in the 1950s.
Several countries have produced postage stamps which depict the northern bald ibis. They include Algeria, Morocco, Sudan, Syria, Turkey, and Yemen, which are breeding or migration locations; Austria, which is seeking to reintroduce the bird; and Jersey, which has a small captive population.
The northern bald ibis is a large, glossy black bird, 70–80 cm (28–31 in) long with a 125–135 cm (49–53 in) wingspan and an average weight of 1.0–1.3 kg (35–46 oz). The plumage is black, with bronze-green and violet iridescence, and there is a wispy ruff on the bird's hind neck. The face and head are dull red and unfeathered, and the long, curved bill and the legs are red. In flight, this bird has powerful, shallow, and flexible wing beats. It gives guttural hrump and high, hoarse hyoh calls at its breeding colonies, but is otherwise silent.
The sexes are similar in plumage, although males are generally larger than females, and, as with other ibises that breed in colonies, have longer bills. The longer-billed males are more successful in attracting a mate. The downy chick has uniformly pale brown plumage, and the fledged juvenile resembles the adult except that it has a dark head, light grey legs, and a pale bill. The unfeathered areas of the young bird's head and neck gradually become red as it matures. Moroccan birds have a significantly longer bill than Turkish birds of the same sex.
If the eastern and western populations are considered to be separable subspecies, it is unclear which should be considered to be the nominate (first-named) form, since the first description of this species was based on a now-extinct population from Switzerland which is of unknown race.
The northern bald ibis is readily distinguished from its close relative, the southern bald ibis of Southern Africa, by the southern species' whitish face. The northern bald can also be confused with the similarly dark-plumaged glossy ibis, which overlaps its range, but it is larger and stockier than that species. In flight, when the bill and face colouration may not be visible, the bald ibis' less rounded wings and shorter neck give it a different profile from glossy ibis, and its relatively short legs mean that its feet do not project beyond the tail, unlike those of the glossy ibis.
Unlike many other ibises, which nest in trees and feed in wetlands, the northern bald ibis breeds on undisturbed cliff ledges, and forages for food in irregularly cultivated, grazed dry areas such as semi-arid steppes, and fallow fields. The close proximity of adequate steppe feeding areas to breeding cliffs is an important habitat requirement.
The northern bald ibis was once widespread across the Middle East, northern Africa, and southern and central Europe; fossil bones have been found at Solothurn dated to the Mesolithic and Neolithic Periods. It bred along the Danube and Rhone Rivers, and in the mountains of Spain, Italy, Germany, Austria and Switzerland (Gesner's original description was of a Swiss bird), and most probably also in the Upper Adriatic region. It used castle battlements as well as cliff ledges for nesting before vanishing from Europe at least three centuries ago. It is also extinct over most of its former range, and now almost the entirety of the wild breeding population of just over 500 birds is in Morocco, at Souss-Massa National Park, where there are three documented colonies, and near the mouth of the Oued Tamri (north of Agadir), where there is a single colony containing almost half the Moroccan breeding population. There is some movement of birds between these two sites.
Religious traditions helped this species to survive in one Turkish colony long after the species had disappeared from Europe, since it was believed that the ibis migrated each year to guide Hajj pilgrims to Mecca. The ibis was protected by its religious significance, and a festival was held annually to celebrate its return north. The Turkish ibis population was centred near the small town of Birecik in the southeast of the country, and during the first half of the 20th century, the Birecik colony maintained a relatively stable population of about 500 breeding pairs, reaching an estimated total population of about 3,000 around 1930. By the 1970s, numbers had drastically declined and a captive breeding program was initiated in 1977 with one adult pair and nine chicks taken from the wild. This program largely failed to revert the decline; there were 400 birds in 1982, five pairs in 1986, and seven pairs in 1987. Only three birds returned from their wintering grounds in 1989, and just one in 1990. The returning birds died before they could reproduce, thus rendering the species extinct in the wild in Turkey as of 1992. Once the wild Turkish population became non-viable, the colony was maintained as a flock which was free-flying for most of the year but caged in autumn to prevent migration.
After the demise of the migratory Turkish colony, the northern bald ibis was known to survive in the wild only at the Moroccan sites, although occasional sightings of birds in Yemen, Eritrea, Saudi Arabia, and Israel during the 1980s and 1990s suggested that there was still a colony somewhere in the Middle East. Intensive field surveys in spring 2002, based on the knowledge of Bedouin nomads and local hunters, revealed that the species had never become completely extinct on the Syrian desert steppes. Following systematic searches, 15 old nesting sites were found, one, near Palmyra, was still hosting an active breeding colony of seven individuals. Although the ibis had been declared extinct in Syria more than 70 years earlier, the bird appears to have been relatively common in the desert areas until 20 years ago, when a combination of overexploitation of its range lands and increasing hunting pressures initiated a dramatic decline.
The Moroccan breeding birds are resident, dispersing along the coast after the nesting season. It has been suggested that coastal fog provides extra moisture for this population, and enables the ibises to remain year-round. In the rest of its former range, away from the Moroccan coastal locations, the northern bald ibis migrated south for the winter, and formerly occurred as a vagrant to Spain, Iraq, Egypt, the Azores, and Cape Verde.
Satellite tagging of 13 Syrian birds in 2006 showed that the three adults in the group, plus a fourth untagged adult, wintered together from February to July in the highlands of Ethiopia, where the species had not been recorded for nearly 30 years. They travelled south on the eastern side of the Red Sea via Saudi Arabia and Yemen, and returned north through Sudan and Eritrea.
This gregarious species commutes in flocks from the cliff breeding sites or winter roosts to its feeding areas, flying in a V formation. The flocks may contain up to 100 birds in winter. During the breeding season, the ibises regularly forage up to 15 km (9.3 mi) from the colony, and, although steppe not in current cultivation is preferred for feeding, they will also use fallow ground, and occasionally even actively cultivated fields.
The northern bald ibis consumes a very wide variety of mainly animal food; faecal analysis of the Moroccan breeding population has shown that lizards and tenebrionid beetles predominate in the diet, although small mammals, ground-nesting birds, and invertebrates such as snails, scorpions, spiders, and caterpillars are also taken. Males will sometimes "scrounge" food from females. As the flock moves across the ground, the ibis uses its long bill to feel for food items in the loose, sandy soil. Since this bird hunts mainly by probing, a soft surface seems to be vital, and it is important that any vegetation is sparse, and not more than 15–20 cm (6–8 in) high.
The northern bald ibis breeds in loosely spaced colonies, nesting on cliff ledges or amongst boulders on steep slopes, usually on the coast or near a river. Volunteer climbers have created extra ledge spaces in the Souss-Massa colonies to ensure that breeding population is not limited by the availability of nest ledges, and artificial nest boxes are used in the managed colony at Birecik. In the past, the birds also nested in buildings.
This ibis starts breeding at three to five years of age, and pairs for life. The male chooses a nest site, cleans it, and then advertises for a female by waving his crest and giving low rumbling calls. Once the birds have paired, the bond is reinforced through bowing displays and mutual preening. The nest is a loose construction of twigs lined with grass or straw. G. eremita normally lays two to four rough-surfaced eggs, which weigh an average of 50.16 g (1.769 oz), and are initially blue-white with brown spots, becoming brown during incubation. An egg in the collection of the British Museum was marked more thickly at the broad end, with "spots and very small blotches of yellowish brown and pale rufous". It was 0.93 in long and 0.68 in wide (2.37 × 1.73 cm). The clutch is incubated for 24–25 days to hatching, the chicks fledge in another 40–50 days, and the first flight takes place at about two months. Both parents incubate and feed the chicks.
The northern bald ibis lives for an average of 20 to 25 years in captivity (oldest recorded male 37 years, oldest recorded female 30 years). The average age in the wild has been estimated as 10 to 15 years.
Although the northern bald ibis was long extinct in Europe, many colonies in Morocco and Algeria survived until the early 20th century, when they began to decline more rapidly, the last colony in Algeria disappearing in the late 1980s. In Morocco there were about 38 colonies in 1940 and 15 in 1975, but the last migratory populations in the Atlas Mountains had vanished by 1989. The species is endangered according to the IUCN scale, with an estimated population in 2018 of around 147 breeding pairs in the wild and over 1,000 in captivity. It was formerly considered critically endangered until heavy conservation action secured the breeding sites in Morocco and even allowed the birds to expand to other sites, as well as the semi-wild population conserved in Turkey as well as the reintroduction projects in Europe. The northern bald ibis is one of the key species to which the draft Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies, and it has a detailed, internationally agreed conservation action plan under the agreement. As a species that is threatened with extinction, it is listed on Appendix 1 of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora), which means that commercial trade in the species (including parts and derivatives) is prohibited.
The northern bald ibis has declined for several centuries, at least partly as a consequence of unidentified natural causes. The more rapid decline in the past hundred years, with a loss of 98% of the population between 1900 and 2002, is the result of a combination of factors. These include significant human persecution, especially hunting, and also the loss of steppe and non-intensive agricultural areas (particularly in Morocco), pesticide poisoning, disturbance, and dam construction. The discovery in Jordan of three dead adults from the Turkish colony seemed to confirm that the overuse of pesticides is still a cause of death on migration. These birds were tracked by satellite after leaving Birecik; they stopped off briefly at the Syrian colony, and were later found dead in the Jordanian desert. Although the cause of death was initially thought to have been from poison, probably laid by chicken farmers to kill rodents, the autopsy revealed that they had actually beenelectrocuted whilst standing on electricity pylons.
