African sacred ibis
The African sacred ibis is a species of ibis, a wading bird of the family Threskiornithidae. It is native to much of Africa, as well as small parts of Iraq, Iran and Kuwait. It is especially known for its role in Ancient Egyptian religion, where it was linked to the god Thoth. The species is currently extirpated from Egypt.
Taxonomy
It is very closely related to the black-headed ibis and the Australian white ibis, with which it forms a superspecies complex, so much so that the three species are considered conspecific by some ornithologists. In mixed flocks these ibises often hybridise. The Australian white ibis is often called the sacred ibis colloquially.Although known to the ancient civilisations of Greece, Rome and especially Africa, ibises were unfamiliar to western Europeans from the fall of Rome until the 19th century, and mentions of this bird in the ancient works of these civilisations were supposed to describe some type of curlew or other bird, and were thus translated as such. In 1758, Linnaeus was convinced that the ancient authors were describing a cattle egret, which he thus described as Ardea ibis. Following the work of Mathurin Jacques Brisson, who calls it Ibis candida in 1760, in the 12th edition of his Systema Naturae of 1766 Linnaeus classifies it as Tantalus ibis. These were also unfamiliar birds that did not occur in Europe at the time, in English in these times called the 'Egyptian ibis' by John Latham, and the 'emseesy' or 'ox-bird' by George Shaw.
In 1790, John Latham provided the first unambiguous modern scientific description of the sacred ibis as Tantalus aethiopicus, mentioning James Bruce of Kinnaird who called it 'abou hannes' in his writings describing his travels in Sudan and Ethiopia, and also described Tantalus melanocephalus of India.
Georges Cuvier named it Ibis religiosus in his Le Règne Animal of 1817.
In 1842, George Robert Gray reclassified the bird under the new genus Threskiornis, because the type of the genus Tantalus was designated as to be the wood stork, also formerly known as the wood ibis or wood pelican, and Gray decided these birds could not be classified in the same genus.
In a comprehensive review of plumage patterns by Holyoak in 1970, it was noted that the three taxa were extremely similar and that the Australian birds resembled Threskiornis aethiopicus in adult plumage and T. melanocephalus in juvenile plumage, he thus proposed they all be considered part of a single species T. aethiopicus. At the time, this was generally accepted by the scientific community; however, in 'The Birds of the Western Palearctic' compendium of 1977, Roselaar advocated splitting the group into four species, recognising T. bernieri, based again on the then known geographical morphological differences.
In 1990, Sibley & Monroe, in the general reference 'Distribution and Taxonomy of Birds of the World' followed Roselaar in recognising four species, which they repeated in 'A World Checklist of Birds' of 1993.
This taxon being split from T. melanocephalus and T. molucca was further advocated by another morphological study by Lowe and Richards in 1991, where they looked at plumage, bill and neck sack morphology and used many more skins. They concluded that the differences were such to merit separate species status for the three taxa, especially as they could find no intergradation in morphological characters in possible contact zones in SE Asia. They also cite observed differences in courtship displays between the Australian and African birds. Based on these characteristics they recommended the Madagascan birds T. bernieri and T. abbotti be considered a subspecies of T. aethiopicus.
Description
An adult individual is long with all-white body plumage apart from dark plumes on the rump. Wingspan is and body weight. Males are generally slightly larger than females.The bald head and neck, thick curved bill and legs are black. The white wings show a black rear border in flight. The eyes are brown with a dark red orbital ring. Sexes are similar, but juveniles have dirty white plumage, a smaller bill and some feathering on the neck, greenish-brown scapulars and more black on the primary coverts.
This bird is usually silent, but occasionally makes puppy-like yelping noises, unlike its vocal relative, the hadada ibis.
Distribution
Native
The sacred ibis breeds in Sub-Saharan Africa and southeastern Iraq. A number of populations are migrant with the rains; some of the South African birds migrate 1,500 km as far north as Zambia, the African birds north of the equator migrate in the opposite direction. The Iraqi population usually migrates to southwestern Iran, but wandering vagrants have been seen as far south as Oman and as far north as the Caspian coasts of Kazakhstan and Russia.Africa
It was formerly found in North Africa including Egypt, where it was commonly venerated and mummified as a votive offering to the god Thoth. For many centuries until the Roman period the main temples buried a few dozen of thousands of birds a year, and to sustain sufficient numbers for the demand for sacrifices by pilgrims from all over Egypt, it was for some time believed that ibis breeding farms existed. Aristotle mentions in c. 350 BC that many sacred ibises are found all over Egypt. Strabo, writing around 20 AD, mentions large amounts of the birds in the streets of Alexandria, where he was living at the time; picking through the trash, attacking provisions, and defiling everything with their dung. Pierre Belon notes the many ibises in Egypt during his travels there in the late 1540s. Benoît de Maillet, in his Description de l'Egypte relates that at the turn of the 17th century, when the great caravans travelled yearly to Mecca, great clouds of ibises would follow them from Egypt for over a hundred leagues into the desert to feed on the dung left at the encampments. By 1850, however, the species had disappeared from Egypt both as a breeding and migrant population, with the last, albeit questionable, sighting in 1864. An examination of the genetic diversity among mummified ibises suggested that there was no reduction in genetic diversity as would be caused if they were bred in captivity and further studies on isotopes suggest that the birds were not just wild caught but came from a wide geographic range.The species did not breed in southern Africa before the beginning of the 20th century, but it has benefited from irrigation, dams, and commercial agricultural practices such as dung heaps, carrion and refuse tips. It began to breed in the early 20th century, and in the 1970s the first colonies of ibises were recorded in Zimbabwe and South Africa. Its population for example expanded 2-3-fold during the period between 1972 and 1995 in Orange Free State. It is now found throughout southern Africa. The species is a common resident in most parts of South Africa. Local numbers are swollen in summer by individuals migrating southwards from the equator.
Elsewhere in Africa it occurs throughout the continent south of the Sahara, but it is largely absent in the deserts of southwestern Africa and probably the rainforests of the Congo. In west Africa it is fairly uncommon across the Sahel, except for the major floodplain systems. It can commonly found breeding along the Niger, in the Inner Niger Delta of Mali, the Logone of C.A.R., Lac Fitri in Chad, the Saloum Delta of Senegal, and other localities in relatively small numbers such as in The Gambia. It is common across eastern Africa and southern Africa. Large numbers can be found in the Sudd swamps and Lake Kundi in Sudan in the dry season. It is fairly widespread along the upper Nile River, and is quite common around Mogadishu, Somalia. In Tanzania there are a number of sites with 500 to 1,000+ birds, totalling some 20,000 birds.
Asia
The bird is also native to Yemen; in 2003 it bred in large numbers on small islands near Haramous and along the Red Sea coast near Hodeidah and Aden, where it was often found at waste-water treatment plants. It has been recorded nesting on a shipwreck in the Red Sea. It is also seen as a vagrant on Socotra.With the Yemen Civil War and famine, there have been no new census reports on the species in Yemen, though an estimate of approximately 30 mature individuals was given in 2015.
The species was fairly common in Iraq in the first half of the 20th century, but by the late 1960s it had become very scarce, with the population thought to number no more than 200 birds. The population was thought to have suffered greatly during the draining of the Mesopotamian Marshes of southeastern Iraq starting in the late 1980s, and feared to have disappeared entirely, but it has continuously been observed breeding in a colony in the Hawizeh Marshes as of 2008, numbering up to 27 adults. It is also native to Kuwait, where it occurs as an extremely rare migrant, with only two known sightings, the last being a flock of 17 in 2007.
There are no records of the bird in Iran before the 1970s; however, small numbers were found overwintering in Khuzestan in 1970. Since the 1990s numbers appear to have slowly increased to a few dozen.
Introduced
The first African sacred ibises brought to Europe were two imported from Egypt to France in the mid-1700s. In the 1800s the first escapes were sighted in Europe. In the 1970s it became fashionable for many zoos in Europe and elsewhere to keep their birds in free-flying colonies, which were allowed to forage in the area but would return to roost in the zoo every day. As such feral populations were established in Italy, France, Spain, Portugal, the Netherlands, the Canary Islands, Florida, Taiwan, the United Arab Emirates and possibly Bahrain.Some studies indicate that the introduced populations in Europe have significant economic and ecological impacts, while others suggest that they constitute no substantial threat to native European bird species.