Жойылып кеткен Реюньон ибисі

Extinct bird that was endemic to Réunion

The Réunion ibis or Réunion sacred ibis (Threskiornis solitarius) is an extinct species of ibis that was endemic to the volcanic island of Réunion in the Indian Ocean. The first subfossil remains were found in 1974, and the ibis was first scientifically described in 1987. Its closest relatives are the Malagasy sacred ibis, the African sacred ibis, and the straw necked ibis. Travellers' accounts from the 17th and 18th centuries described a white bird on Réunion that flew with difficulty and preferred solitude, which was subsequently referred to as the "Réunion solitaire". In the mid 19th century, the old travellers' accounts were incorrectly assumed to refer to white relatives of the dodo, due to one account specifically mentioning dodos on the island, and because 17th century paintings of white dodos had recently surfaced. However, no fossils referable to dodo like birds were ever found on Réunion, and it was later questioned whether the paintings had anything to do with the island. Other identities were suggested as well, based only on speculations. In the late 20th century, the discovery of ibis subfossils led to the idea that the old accounts actually referred to an ibis species instead. The idea that the "solitaire" and the subfossil ibis are identical was met with limited dissent, but is now widely accepted. Combined, the old descriptions and subfossils show that the Réunion ibis was mainly white, with this colour merging into yellow and grey. The wing tips and plumes of ostrich like feathers on its rear were black. The neck and legs were long, and the beak was relatively straight and short for an ibis. It was more robust in build than its extant relatives, but was otherwise quite similar to them. It would have been no longer than 65 cm (25 in) in length. Subfossil wingbones indicate it had reduced flight capabilities, a feature perhaps linked to seasonal fattening. The diet of the Réunion ibis was worms and other items foraged from the soil. In the 17th century, it lived in mountainous areas, but it may have been confined to these remote heights by heavy hunting by humans and predation by introduced animals in the more accessible areas of the island. Visitors to Réunion praised its flavour, and therefore sought after its flesh. These factors are believed to have driven the Réunion ibis to extinction by the early 18th century.

The taxonomic history of the Réunion ibis is convoluted and complex, due to the ambiguous and meagre evidence that was available to scientists until the late 20th century. The supposed "white dodo" of Réunion is now believed to have been an erroneous conjecture based on the few contemporary reports which described the Réunion ibis, combined with paintings of white dodos from Mauritius by the Dutch painters Pieter Withoos and Pieter Holsteyn II (and derivatives) from the 17th century that surfaced in the 19th century. Blockquote|There were also Dod eersen [old Dutch for dodos], which have small wings, and so far from being able to fly, they were so fat that they could scarcely walk, and when they tried to run, they dragged their under side along the ground. Since Bontekoe was shipwrecked and lost all his belongings after visiting Réunion in 1619, he may not have written his account until he returned to Holland, seven years later, which would put its reliability in question.

In the 1770s, the French naturalist Comte de Buffon stated that the dodo inhabited both Mauritius and Réunion for unclear reasons. He also combined accounts about the Rodrigues solitaire and a bird from Mauritius ("oiseau de Nazareth", now thought to be a dodo), as well as the "solitaire" Carré reported from Réunion under one "solitaire" section, indicating he believed there was both a dodo and "solitaire" on Réunion. The Belgian scientist Edmond de Sélys Longchamps coined the scientific name Apterornis solitarius for the "solitaire" in 1848, apparently making it the type species of the genus, in which he also included two other Mascarene birds only known from contemporary accounts, the red rail and the Réunion swamphen. As the name Apterornis had already been used for a different bird by the English biologist Richard Owen, and the other former names were likewise invalid, Bonaparte coined the new binomial Ornithaptera borbonica in 1854 (Bourbon was the original French name for Réunion). He restored it strictly according to contemporary accounts, which resulted in an ibis or stork like bird instead of a dodo. In 1869, the English ornithologist Alfred Newton argued that the Withoos' painting and engraving in Bontekoe's memoir depicted a living Réunion dodo that had been brought to Holland, while explaining its blunt beak as a result of beak trimming to prevent it from injuring humans. He also brushed aside the inconsistencies between the illustrations and descriptions, especially the long, thin beak implied by one contemporary account. Newton's words particularly cemented the validity of this connection among contemporary peers, and several of them expanded on his views. The British zoologist Walter Rothschild claimed in 1907 that the yellow wings might have been due to albinism in this particular specimen, since the old descriptions described these as black. By the early 20th century, many other paintings and even physical remains were claimed to be of white dodos, amid much speculation. The first subfossil bird remains on Réunion, the lower part of a tarsometatarsus, was found in 1974, and considered a new species of stork in the genus Ciconia by the British ornithologist Graham S. Cowles in 1987. The remains were found in a cave, which indicated it had been brought there and eaten by early settlers. It was speculated that the remains could have belonged to a large, mysterious bird described by Leguat, and called "Leguat's giant" by some ornithologists. "Leguat's giant" is now thought to be based on a locally extinct population of greater flamingos. Also in 1987, a subfossil tarsometatarsus of an ibis found in a cave was described as Borbonibis latipes (the specific name means "wide foot") by the French palaeontologists Cécile Mourer Chauviré and François Moutou, and thought related to the bald ibises of the genus Geronticus. In 1994, Cowles concluded that the "stork" remains he had reported belonged to Borbonibis, since their tarsometatarsi were similar. The 1987 discovery led the English biologist Anthony S. Cheke to suggest to one of the describers of Borbonibis that the subfossils may have been of the "solitaire". In 1995, the describers of Borbonibis latipes suggested that it represented the "Réunion solitaire", and reassigned it to the ibis genus Threskiornis, now combined with the specific name solitarius from de Sélys Longchamps' 1848 binomial for the "solitaire" (making Borbonibis latipes a junior synonym). The authors pointed out that the contemporary descriptions matched the appearance and behaviour of an ibis more than a member of the Raphinae, especially due to its comparatively short and straight mandible, and because ibis remains were abundant in some localities; it would be strange if contemporary writers never mentioned such a relatively common bird, whereas they mentioned most other species subsequently known from fossils. Valledor de Lozoya instead suggested that the light plumage was a juvenile trait, a result of bleaching of old taxidermy specimens, or simply due to artistic license. In 2018, the British ornithologist Jolyon C. Parish and Cheke suggested that the painting was instead executed after 1614, or even after 1626, based on some of the motifs. While many subfossil elements from throughout the skeleton have been assigned to the Réunion ibis, no remains of dodo like birds have ever been found on Réunion. Cheke and Hume have dismissed such sentiments as being mere "belief" and "hope" in the existence of a dodo on the island. Cheke and Hume instead suggested that it was closest to the Malagasy sacred ibis (T. bernieri), and therefore of ultimately African origin. The Réunion ibis appears to have lived in high altitudes, and perhaps had a limited distribution. Accounts by early visitors indicate the species was found near their landing sites, but they were found only in remote places by 1667. The bird may have survived in eastern lowlands until the 1670s. Though many late 17th century accounts state the bird was good food, Feuilley stated it tasted bad. This may be because it changed its diet when it moved to more rugged, higher terrain, to escape pigs that destroyed its nests; since it had limited flight capabilities, it probably nested on the ground. Many other endemic species of Réunion became extinct after the human colonisation and the resulting disruption of the island's ecosystem. The Réunion ibis lived alongside other recently extinct birds such as the hoopoe starling, the Mascarene parrot, the Réunion parakeet, the Réunion swamphen, the Réunion scops owl, the Réunion night heron, and the Réunion pink pigeon. Extinct reptiles include the Réunion giant tortoise and an undescribed Leiolopisma skink. The small Mauritian flying fox and the snail Tropidophora carinata lived on Réunion and Mauritius, but vanished from both islands.