Réunion ibis
Réunion ibis | |
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Hypothetical subfossil remains, and extant relatives
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Pelecaniformes |
Family: | Threskiornithidae |
Genus: | Threskiornis |
Species: | †T. solitarius
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Binomial name | |
†Threskiornis solitarius (de Sélys-Longchamps, 1848)
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Location of Réunion (encircled) | |
Synonyms | |
List
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The Réunion ibis or Réunion sacred ibis (Threskiornis solitarius) is an
In the mid 19th century, the old travellers' accounts were incorrectly assumed to refer to white relatives of the
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
Taxonomy
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.[2]
The English Chief Officer John Tatton was the first to mention a specifically white bird on Réunion, in 1625. The French occupied the island from 1646 and onwards, and referred to this bird as the "solitaire". M. Carré of the French East India Company described the "solitaire" in 1699, explaining the reason for its name:[2]
I saw a kind of bird in this place which I have not found elsewhere; it is that which the inhabitants call the Oiseaux Solitaire for to be sure, it loves solitude and only frequents the most secluded places; one never sees two or more together; it is always alone. It is not unlike a turkey, if it did not have longer legs. The beauty of its plumage is a delight to see. It is of changeable colour which verges upon yellow. The flesh is exquisite; it forms one of the best dishes in this country, and might form a dainty at our tables. We wished to keep two of these birds to send to France and present them to His Majesty, but as soon as they were on board ship, they died of melancholy, having refused to eat or drink.[3]
The
The two individuals Carré attempted to send to the royal menagerie in France did not survive in captivity. Billiard claimed that the French administrator Bertrand-François Mahé de La Bourdonnais sent a "solitaire" to France from Réunion around 1740. Since the Réunion ibis is believed to have gone extinct by this date, the bird may actually have been a Rodrigues solitaire.[5]
The only contemporary writer who referred specifically to "dodos" inhabiting
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.[3]
When his journal was published in 1646, it was accompanied by an engraving which is now known to have been copied after one of the dodos in the Flemish painter Roelant Savery's "Crocker Art Gallery sketch".[5] 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.[2] He may have concluded in hindsight that it was a dodo, finding what he saw similar to accounts of that bird.[7]
Early interpretation
In the 1770s, the French naturalist
The Belgian scientist
In 1856, William Coker announced the discovery of a 17th-century "
Newton's words particularly cemented the validity of this connection among contemporary peers, and several of them expanded on his views.
By the early 20th century, many other paintings and even physical remains were claimed to be of white dodos, amid much speculation.
Modern interpretation
Until the late 1980s, belief in the existence of a white dodo on Réunion was the orthodox view, and only a few researchers doubted the connection between the "solitaire" accounts and the dodo paintings. The American ornithologist
The first subfossil bird remains on Réunion, the lower part of a
In 1994, Cowles concluded that the "stork" remains he had reported belonged to Borbonibis, since their tarsometatarsi were similar.
The possible origin of the 17th-century white dodo paintings was examined, by the Spanish biologist Arturo Valledor de Lozoya in 2003, and independently by experts of Mascarene fauna Cheke and
Savery's several later dodo images all show greyish birds, possibly because he had by then seen a normal specimen. Cheke and Hume concluded the painted specimen was white due to albinism, and that this peculiar feature was the reason it was collected from Mauritius and brought to Europe.[2] 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.[16] 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.[25]
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.[9] A few later sources have taken issue with the proposed ibis-identity of the "solitaire", and have even regarded the "white dodo" as a valid species.[5] The British writer Errol Fuller agrees that the 17th-century paintings do not depict Réunion birds, but has questioned whether the ibis subfossils are necessarily connected to the "solitaire" accounts. He notes that no evidence indicates the extinct ibis survived until the time Europeans reached Réunion.[26][27] Cheke and Hume have dismissed such sentiments as being mere "belief" and "hope" in the existence of a dodo on the island.[2]
Evolution
The volcanic island of Réunion is only three million years old, whereas Mauritius and Rodrigues, with each of their flightless Raphine species, are eight to ten million years old, and according to Cheke and Hume it is unlikely that either bird would have been capable of flying after five or more million years of adapting to the islands. Therefore, it is unlikely that Réunion could have been colonised by flightless birds from these islands, and only flighted species on the island have relatives there.[2] Three million years is enough time for flightless and weak flying abilities to have evolved in bird species on Réunion itself, but Mourer-Chauviré and colleagues pointed out that such species would have been wiped out by the eruption of the volcano Piton des Neiges between 300,000 and 180,000 years ago. Most recent species would therefore likely be descendants of animals which had recolonised the island from Africa or Madagascar after this event, which is not enough time for a bird to become flightless.[9]
In 1995, a morphological study by Mourer-Chauviré and colleagues suggested the closest extant relatives of the Réunion ibis are the African sacred ibis (T. aethiopicus) of Africa and the straw-necked ibis (T. spinicollis) of Australia.[24] Cheke and Hume instead suggested that it was closest to the Malagasy sacred ibis (T. bernieri), and therefore of ultimately African origin.[5]
Description
Contemporary accounts described the species as having white and grey plumage merging into yellow, black wing tips and tail feathers, a long neck and legs, and limited flight capabilities.[26] Dubois' 1674 account is the most detailed contemporary description of the bird,[14] here as translated by Strickland in 1848:
Solitaires. These birds are so called because they always go alone. They are the size of a large Goose, and are white, with the tips of the wings and tail black. The tail feathers resemble those of an Ostrich; the neck is long, and the beak is like that of a Woodcock, but larger; the legs and feet like those of Turkeys. This bird has recourse to running, as it flies but very little.[3]
According to Mourer-Chauviré and colleagues, the plumage colouration mentioned is similar to that of the related African sacred ibis and straw-necked ibis, which are also mainly white and glossy black. In the reproductive season, the ornamental feathers on the back and wing tips of the African sacred ibis look similar to the feathers of an ostrich, which echoes Dubois' description. Likewise, a subfossil lower jaw found in 1994 showed that the bill of the Réunion ibis was relatively short and straight for an ibis, which corresponds with Dubois' woodcock comparison.[24] Cheke and Hume have suggested that the French word (bécasse) from Dubois' original description, usually translated to "woodcock", could also mean oystercatcher, another bird with a long, straight, but slightly more robust, bill. They have also pointed out that the last sentence is mistranslated, and actually means the bird could be caught by running after it.[2] The bright colouration of the plumage mentioned by some authors may refer to iridescence, as seen in the straw-necked ibis.[7]
Subfossils of the Réunion ibis show that it was more robust, likely much heavier, and had a larger head than the African sacred and straw-necked ibises. It was nonetheless similar to them in most features. According to Hume, it would have been no longer than 65 cm (25 in) in length, the size of the African sacred ibis. Rough protuberances on the wing bones of the Réunion ibis are similar to those of birds that use their wings in combat. It was perhaps flightless, but this has not left significant
Behaviour and ecology
As contemporary accounts are inconsistent on whether the "solitaire" was flightless or had some flight capability, Mourer-Chauvire and colleagues suggested that this was dependent on seasonal fat-cycles, meaning that individuals fattened themselves during cool seasons, but were slim during hot seasons; perhaps it could not fly when it was fat, but could when it was not.[24] However, Dubois specifically stated the "solitaires" did not have fat-cycles, unlike most other Réunion birds.[2] The only mention of its diet and exact habitat is the account of the French cartographer Jean Feuilley from 1708, which is also the last record of a living individual:
The solitaires are the size of an average turkey cock, grey and white in colour. They inhabit the tops of mountains. Their food is only worms and filth, taken on or in the soil.[5]
The diet and mode of
The Réunion ibis appears to have lived in high altitudes, and perhaps had a limited distribution.[4] 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.[5]
Many other
Extinction
As Réunion was populated by settlers, the Réunion ibis appears to have become confined to the tops of mountains. Introduced predators such as cats and rats took a toll. Overhunting also contributed and several contemporary accounts state the bird was widely hunted for food.[4] In 1625, John Tatton described the tameness of the bird and how easy it was to hunt, as well as the large quantity consumed:
There is store of land fowle both small and great, plenty of Doves, great Parrats, and such like; and a great fowle of the bignesse of a Turkie, very fat, and so short winged, that they cannot fly, being white, and in a manner tame: and so be all other fowles, as having not been troubled nor feared with shot. Our men did beat them down with sticks and stones. Ten men may take fowle enough to serve fortie men a day.[14]
In 1671, Melet mentioned the culinary quality of this species, and described the slaughter of several types of birds on the island:
(A)nother sort of bird called solitaires which are very good (to eat) and the beauty of their plumage is most fascinating for the diversity of bright colours that shine on their wing and around their necks... There are birds in such great confusion and so tame that it is not necessary to go hunting with firearms, they can so easily be killed with a little stick or rod. During the five or six days that we were allowed to go into the woods, so many were killed that our General [de La Haye] was constrained to forbid anyone going beyond a hundred paces from the camp for fear the whole quarter would be destroyed, for one needed only to catch one bird alive and make it cry out, to have in a moment whole flocks coming to perch on people, so that often without moving from one spot one could kill hundreds. But, seeing that it would have been impossible to wipe out such a huge quantity, permission was again given to kill, which gave great joy to everyone, because very good fare was had at no expense.[4]
The last definite account of the "solitaire" of Réunion was Feuilley's from 1708, indicating that the species probably became extinct sometime early in the century.
References
- . Retrieved 12 November 2021.
- ^ .
- ^ a b c d Strickland, H. E.; Melville, A. G. (1848). The Dodo and Its Kindred; or the History, Affinities, and Osteology of the Dodo, Solitaire, and Other Extinct Birds of the Islands Mauritius, Rodriguez, and Bourbon. London: Reeve, Benham and Reeve. pp. 57–62.
- ^ ISBN 978-1-4081-5725-1.
- ^ ISBN 978-0-7136-6544-4.)
{{cite book}}
: CS1 maint: location missing publisher (link - ^ Bontekoe van Hoorn, W. (1646). Journael ofte Gedenk waerdige beschrijvinghe van de Oost-Indische Reyse van Willem Ysbrantz. Bontekoe van Hoorn (in Dutch). Amsterdam: Jooft Hartgers. p. 76.
- ^ a b Mourer-Chauviré, C.; Bour, S.; Ribes, R. (2006). "Recent avian extinctions on Réunion (Mascarene islands) from paleontological and historical sources". Bulletin of the British Ornithologists' Club (126): 40–48.
- ISBN 978-0-87474-804-8.
- ^ hdl:10088/2005.
- ^ Schlegel, H. (1854). "Ook een Woordje over den Dodo (Didus ineptus) en zijne Verwanten". Verslagen en Mededeelingen der Koninklijke Akademie van Wetenschappen (in Dutch). 2: 232–256.
- ^ ISBN 978-0-253-00099-6.
- .
- .
- ^ a b c d Rothschild, W. (1907). Extinct Birds. London: Hutchinson & Co. pp. 171–176.
- ^ a b Hachisuka, M. (1937). "Revisional note on the didine birds of Réunion". Proceedings of the Biological Society of Washington. 50: 69–71.
- ^ .
- .
- ISBN 978-0-486-21869-4.
- JSTOR 4083934.
- ISBN 978-0-511-73576-9.)
{{cite book}}
: CS1 maint: location missing publisher (link - Comptes Rendus de l'Académie des Sciences(in French). 305 (5): 419–423.
- .
- ^ Probst, J.-M. (1995). "Découverte d'un bec appartenant au Solitaire de Bourbon?". Bulletin Phaethon. 1: 44–45.
- ^ S2CID 4304082.
- S2CID 89661119.
- ^ ISBN 978-0-00-714572-0.
- ISBN 978-0-8014-3954-4.
- S2CID 198258434.
External links
- Media related to Threskiornis solitarius at Wikimedia Commons
- Data related to Threskiornis solitarius at Wikispecies