Broad-billed parrot: Difference between revisions
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The Broad-billed Parrot possessed a distinct frontal [[crest (feathers)|crest]] of feathers. Ridges on the skull indicate that this crest was firmly attached, and that the bird, unlike [[cockatoo]]s, could not raise or lower it.<ref name=4to17Hume2007/> The 1601 ''Gelderland'' sketch was examined in 2003 by Julian Hume, who compared the ink finish with the underlying pencil sketch and found that the latter showed several additional details. The pencil sketch depicts the crest as a tuft of rounded feathers attached to the front of the head at the base of the beak, and shows long primary [[covert feathers]], large [[secondary feathers]], and a slightly bifurcated tail.<ref name="Gelderland"/> |
The Broad-billed Parrot possessed a distinct frontal [[crest (feathers)|crest]] of feathers. Ridges on the skull indicate that this crest was firmly attached, and that the bird, unlike [[cockatoo]]s, could not raise or lower it.<ref name=4to17Hume2007/> The 1601 ''Gelderland'' sketch was examined in 2003 by Julian Hume, who compared the ink finish with the underlying pencil sketch and found that the latter showed several additional details. The pencil sketch depicts the crest as a tuft of rounded feathers attached to the front of the head at the base of the beak, and shows long primary [[covert feathers]], large [[secondary feathers]], and a slightly bifurcated tail.<ref name="Gelderland"/> |
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A 1602 account by Reyer Cornelisz contains the only contemporary mention of size differences among Broad-billed Parrots, listing "large and small Indian Crows" among the animals of the island. This observation may indicate [[sexual dimorphism]], as may the size differences between the two birds in the 1601 sketch and among subfossil specimens. Subfossils show that the males were larger, measuring 55–65 cm (22.6–25.5 in) to the females' 45–55 cm (18.7–22.6 in) and that both sexes had disproportionately large heads and beaks. The size difference between male and female skulls is the largest among parrots.<ref name=4to17Hume2007/> Differences in the bones of the rest of the body and limbs are less pronounced; nevertheless, it had greater sexual dimorphism in overall size than any living parrot.<ref name= |
A 1602 account by Reyer Cornelisz contains the only contemporary mention of size differences among Broad-billed Parrots, listing "large and small Indian Crows" among the animals of the island. This observation may indicate [[sexual dimorphism]], as may the size differences between the two birds in the 1601 sketch and among subfossil specimens. Subfossils show that the males were larger, measuring 55–65 cm (22.6–25.5 in) to the females' 45–55 cm (18.7–22.6 in) and that both sexes had disproportionately large heads and beaks. The size difference between male and female skulls is the largest among parrots.<ref name=4to17Hume2007/> Differences in the bones of the rest of the body and limbs are less pronounced; nevertheless, it had greater sexual dimorphism in overall size than any living parrot.<ref name=4to17Hume2007/> Unlike other Mascarene parrots, it had a flattened skull.<ref name=4to17Hume2007/> |
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[[File:Lophopsittacus.jpg|left|thumb|alt=Painting of a blue Broad-billed Parrot|Restoration by [[Henrik Grönvold]], 1907, based on a tracing of the ''Gelderland'' sketch, showing the bird as entirely blue]] |
[[File:Lophopsittacus.jpg|left|thumb|alt=Painting of a blue Broad-billed Parrot|Restoration by [[Henrik Grönvold]], 1907, based on a tracing of the ''Gelderland'' sketch, showing the bird as entirely blue]] |
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There has been some confusion over its colouration.<ref name="Fuller Extinct">{{cite book |
There has been some confusion over its colouration.<ref name="Fuller Extinct">{{cite book |
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Revision as of 07:51, 29 December 2012
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| Genus: | Lophopsittacus Newton, 1875
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| Species: | L. mauritianus
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| Lophopsittacus mauritianus (Owen, 1866)
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The Broad-billed Parrot or Raven Parrot (Lophopsittacus mauritianus) is a large extinct parrot in the family Psittaculidae. It was endemic to the Mascarene island of Mauritius in the Indian Ocean east of Madagascar. It is unclear what species it is most closely related to, but it has been classified as a member of the tribe Psittaculini, along with other Mascarene parrots.
The Broad-billed Parrot's head was large in proportion to its body, and there was a distinct crest of feathers on the front of the head. The bird had a very large beak, comparable in size to that of the Hyacinth Macaw, which would have enabled it to crack hard seeds. Subfossil bones indicate that the species exhibited greater sexual dimorphism in overall size and head size than any living parrot. The exact colouration is unknown, but a contemporary description indicates that it had a blue head, a greyish or blackish body, and perhaps a red beak. It is believed to have been a weak flier, but not flightless.
The Broad-billed Parrot was first referred to as the "Indian Raven" in Dutch ships' journals from 1598 onwards. Only a handful of brief contemporary descriptions and three depictions are known. It was first scientifically described from a subfossil mandible in 1866, but this was not linked to the old accounts until the rediscovery of a detailed 1601 sketch that matched both descriptions. The bird became extinct in the 17th century owing to a combination of deforestation, predation by introduced invasive species, and probably also because of hunting by humans.
Taxonomy
The earliest known descriptions of the Broad-billed Parrot were provided by Dutch travellers during the Second Dutch Expedition to Indonesia, led by Admiral Jacob Cornelis van Neck in 1598. They appear in reports published in 1601, which also contain the first illustration of the bird, along with the first of a Dodo. The Dutch sailors who visited Mauritius categorised the Broad-billed Parrots separately from parrots, and referred to them as "Indische Ravens" (translated as either "Indian Ravens" or "Indian Crows"), which caused confusion when their journals were studied. The English naturalist Hugh Edwin Strickland assigned them to the hornbill genus Buceros, because he interpreted the projection on the forehead in a basic illustration as a horn.[2] The Dutch and the French also referred to South American macaws as "Indian Ravens" during the 17th century, and the name was even used for hornbills by Dutch, French, and English speakers in the East Indies.[3] Sir Thomas Herbert referred to the Broad-billed Parrot as "Cacatoes" (Cockatoo) in 1634, with the description "birds like Parrats [sic], fierce and indomitable", but naturalists did not realise that he was referring to the same bird.[2] Even after subfossils of a parrot matching the descriptions were found, French zoologist Emile Oustalet argued that the "Indian Raven" was a hornbill whose remains awaited discovery. France Staub was in favour of this idea as late as 1993. No remains of hornbills have ever been found on the island, and apart from an extinct species from New Caledonia, hornbills are not found on any oceanic islands.[3]
The first known physical remains of the Broad-billed Parrot were a subfossil mandible collected along with the first batch of Dodo bones found in the Mare aux Songes swamp.[4] Richard Owen described the mandible in 1866 and identified it as belonging to a large parrot species, to which he gave the binomial name Psittacus mauritianus and the common name "Broad-billed Parrot".[5] In 1868, shortly after the 1601 journal of the Dutch East India Company ship Gelderland had been rediscovered, Hermann Schlegel examined an unlabelled pen-and-ink sketch in it. Realising that the drawing, which is attributed to the artist Joris Joostensz Laerle, depicted the parrot described by Owen, Schlegel made the connection with the old journal descriptions. In 1875, because its bones and crest are significantly different from those of Psittacus species, Alfred Newton assigned it to its own genus, which he called Lophopsittacus.[6] Lophos is the Ancient Greek word for crest, referring here to the bird's frontal crest, and psittakos is Ancient Greek for parrot.[3][7]
Evolution
The taxonomic affinities of the Broad-billed Parrot are undetermined. Considering its large jaws and other osteological features, Edward Newton and Hans Gadow thought it to be closely related to the Rodrigues Parrot, but they kept the two species in separate genera because of the distinct crest of the former.[8]
Many endemic Mascarene birds, including the Dodo, are derived from South Asian ancestors, and the English palaeontologist Julian Hume has proposed that this may be the case for the parrots as well. Sea levels were lower during the Pleistocene, so it was possible for species to "island hop" to some of the then less isolated islands. Of the approximately eight endemic Mascarene parrot species, all but the Mauritius Parakeet have become extinct. Although many of them are poorly known, subfossil remains show that they shared features such as enlarged heads and jaws, reduced pectoral elements, and robust leg elements. Hume has suggested that they have a common origin in the radiation of the Psittaculini tribe, basing his theory on morphological features and the fact that Psittacula parrots have managed to colonise many isolated islands in the Indian Ocean.[3] The Psittaculini may have invaded the area several times, as many of the species were so specialised that they may have evolved significantly on hotspot islands before the Mascarenes emerged from the sea.[2] A 2012 genetic study, however, shows that the Mascarene Parrot is most closely related to the Lesser Vasa Parrot from Madagascar and nearby islands, and is therefore unrelated to the Psittacula parrots.[9] This is surprising, considering its anatomical similarities to other Mascarene parrots that are believed to be Psittaculines.[4]
In 1973, based on remains collected by Louis Etienne Thirioux in the early 20th century, D. T. Holyoak placed a small subfossil Mauritian parrot in the same genus as the Broad-billed Parrot and named it Lophopsittacus bensoni.[10] In 2007, on the basis of a comparison of subfossils together with 17th and 18th century descriptions, Hume reclassified it as a species in the genus Psittacula and called it Thirioux's Grey Parrot.[3]
Description
The Broad-billed Parrot possessed a distinct frontal crest of feathers. Ridges on the skull indicate that this crest was firmly attached, and that the bird, unlike cockatoos, could not raise or lower it.[3] The 1601 Gelderland sketch was examined in 2003 by Julian Hume, who compared the ink finish with the underlying pencil sketch and found that the latter showed several additional details. The pencil sketch depicts the crest as a tuft of rounded feathers attached to the front of the head at the base of the beak, and shows long primary covert feathers, large secondary feathers, and a slightly bifurcated tail.[11]
A 1602 account by Reyer Cornelisz contains the only contemporary mention of size differences among Broad-billed Parrots, listing "large and small Indian Crows" among the animals of the island. This observation may indicate sexual dimorphism, as may the size differences between the two birds in the 1601 sketch and among subfossil specimens. Subfossils show that the males were larger, measuring 55–65 cm (22.6–25.5 in) to the females' 45–55 cm (18.7–22.6 in) and that both sexes had disproportionately large heads and beaks. The size difference between male and female skulls is the largest among parrots.[3] Differences in the bones of the rest of the body and limbs are less pronounced; nevertheless, it had greater sexual dimorphism in overall size than any living parrot.[3] Unlike other Mascarene parrots, it had a flattened skull.[3]
There has been some confusion over its colouration.[12] The report of van Neck's 1589 voyage, published in 1601, contained the first illustration of the parrot, captioned with the following description:
5* Is a bird which we called the Indian Crow, more than twice as big as the parroquets, of two or three colours.[13]
The last account, and the only mention of specific colours, is by Johann Christian Hoffman in 1673–75:
There are also geese, flamingos, three species of pigeon of varied colours, mottled and green perroquets, red crows with recurved beaks and with blue heads, which fly with difficulty and have received from the Dutch the name of ‘Indian crow’.[13]
The head was evidently blue, and the beak may have been red, as is characteristic of Psittaculini. The rest of the plumage may have been greyish or blackish, which also occurs in other members of Psittaculini.[3] In spite of the mention of several colours, authors such as Walter Rothschild claimed that the Gelderland journal described the bird as entirely blue-grey, and it was restored this way in Rothschild's 1907 book Extinct Birds. Later examination of the journal has revealed only a description of the Dodo. The distinctively drawn facial mask may represent a separate colour.[11][14]
Behaviour and ecology
Little is known about the behaviour of the Broad-billed Parrot. The terms Raven or Crow may have been suggested by the bird's harsh call, its behavioural traits, or just its dark plumage. It may have nested in tree cavities or rocks, like the Cuban Amazon. The Broad-billed Parrot was recorded on the dry leeward side of Mauritius, which was the most accessible for people, and it was noted that birds were more abundant near the coast, which may indicate that the fauna of such areas was more diverse.[3]
Sexual dimorphism in beak size may have affected behaviour. Such dimorphism is common in other parrots, for example in the Palm Cockatoo and the New Zealand Kaka,[3][15] and in species where it occurs, the sexes prefer food of different sizes, the males use their beaks in rituals, or the sexes have specialised roles in nesting and rearing. Similarly, the large difference between male and female head size may have been reflected in the ecology of each sex, though it is impossible to determine how.
The following description by Jacob Granaet from 1666 identifies its forest habitat and might indicate its demeanour:
Within the forest dwell parrots, turtle and other wild doves, mischievous and unusually large ravens [Broad-billed Parrots], falcons, bats and other birds whose name I do not know, never having seen before.[13]
Though the Broad-billed Parrot may have fed on the ground and been a weak flier, its tarsometatarsus was short and stout, implying some arboreal characteristics. The Newton brothers and many authors after them inferred that it was flightless, due to the apparent short wings and large size shown in the 1601 Gelderland sketch. According to Julian Hume, the underlying pencil sketch actually shows that the wings are not particularly short. They appear broad, as they commonly are in forest-adapted species, and the alula appears large, a feature of slow-flying birds. Its sternal keel was reduced, but not enough to prevent flight, as the adept flying Cyanoramphus parrots also have reduced keels, and even the flightless Kakapo, with its vestigial keel, is capable of gliding.[3] Furthermore, Hoffman's account states that it could fly, albeit with difficulty, and the first published illustration shows the bird on top of a tree, an improbable position for a flightless bird.[11]
Masauji Hachisuka suggested the Broad-billed Parrot was nocturnal, like the Kakapo and the Night Parrot, two extant ground-dwelling parrots. Contemporary accounts do not corroborate this, and the orbits are of similar size to those of other large diurnal parrots.[3]
Many other endemic species of Mauritius were lost after the arrival of man, so the ecosystem of the island is severely damaged and hard to reconstruct. Before humans arrived, Mauritius was entirely covered in forests, of which very little remains today, because of deforestation.[16] The surviving endemic fauna is still seriously threatened.[17] The Broad-billed Parrot lived alongside other recently extinct Mauritian birds such as the Dodo, the Red Rail, Thirioux's Grey Parrot, the Mauritius Blue Pigeon, the Mauritius Owl, the Mascarene Coot, the Mauritian Shelduck, the Mauritian Duck, and the Mauritius Night Heron. Extinct Mauritian reptiles include the saddle-backed Mauritius giant tortoise, the domed Mauritius giant tortoise, the Mauritian giant skink, and the Round Island burrowing boa. The small Mauritian flying fox and the snail Tropidophora carinata lived on Mauritius and Réunion but became extinct in both islands. Some plants, such as Casearia tinifolia and the Palm Orchid, have also become extinct.[2]
Diet
Species that are morphologically similar to the Broad-billed Parrot, such as the Hyacinth Macaw and the Palm Cockatoo, may provide insight into its ecology. Anodorhynchus macaws, which are habitual ground dwellers, eat very hard palm nuts.[3] Carlos Yamashita has suggested that these macaws once depended on now-extinct South American megafauna to eat fruits and excrete the seeds, and that they later relied on domesticated cattle to do this. Similarly, in Australasia the Palm Cockatoo feeds on undigested seeds from cassowary droppings.[3] Yamashita suggests that the abundant Cylindraspis tortoises and Dodos performed the same function on Mauritius, and that the Broad-Billed Parrot, with its macaw-like beak, depended on them to obtain cleaned seeds.[18] Many types of palms and palm-like plants on Mauritius produce hard seeds that the Broad-billed Parrot may have eaten, including Latania loddigesii, Mimusops maxima, Sideroxylon grandiflorum, Diospyros egrettorium, and Pandanus utilis.[3]
On the basis of radiographs, D. T. Holyoak claimed that the mandible of the Broad-billed Parrot was weakly constructed and suggested that it would have fed on soft fruits rather than hard seeds.[19] As evidence, he pointed out that the internal trabeculae were widely spaced, that the upper bill was broad whereas the palatines were narrow, and the fact that no preserved upper rostrum had been discovered, which he attributed to its delicateness.[20] G. A. Smith, however, pointed out that the four genera Holyoak used as examples of "strong jawed" parrots based on radiographs, Cyanorhamphus, Melopsittacus, Neophema and Psephotus, actually have weak jaws in life, and that the morphologies cited by Holyoak do not indicate strength.[21] Julian Hume has since pointed out that the mandible morphology of the Broad-billed Parrot is comparable to that of the largest living parrot, the Hyacinth Macaw, which cracks open palm nuts with ease. It is therefore probable that the Broad-billed Parrot fed in the same manner.[22]
Extinction
Because of its poor flying ability, large size and possibly confiding nature, the Broad-billed Parrot was easy prey for sailors who visited Mauritius, and their nests would have been extremely vulnerable to predation by introduced crab-eating macaques and rats. The bird is believed to have become extinct by the 1680s, when the palms it may have specialised in were harvested on a large scale. Unlike other parrot species, which were often taken as pets by sailors, there are no records of Broad-billed Parrots being transported from Mauritius, perhaps because of the stigma associated with ravens.[3] The birds would not in any case have survived such a journey if they refused to eat anything but seeds.[18]
References
- ^ Template:IUCN
- ^ a b c d Cheke, A. S.; Hume, J. P. (2008). Lost Land of the Dodo: an Ecological History of Mauritius, Réunion & Rodrigues. New Haven and London: T. & A. D. Poyser. pp. 23–25. ISBN 978-0-7136-6544-4. Cite error: The named reference "Lost Land" was defined multiple times with different content (see the help page).
- ^ a b c d e f g h i j k l m n o p q r Hume, J. P. (2007). "Reappraisal of the parrots (Aves: Psittacidae) from the Mascarene Islands, with comments on their ecology, morphology, and affinities" (PDF). Zootaxa. 1513: 4–17.
- ^ a b Hume, J. P.; Walters, M. (2012). Extinct Birds. London: A & C Black. pp. 180–181. ISBN 140815725X.
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1111/j.1474-919X.1866.tb06084.x, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1111/j.1474-919X.1866.tb06084.xinstead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1111/j.1474-919X.1876.tb06925.x, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1111/j.1474-919X.1876.tb06925.xinstead. - ^ Jobling, J. A (2012). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 230. ISBN 978-1-4081-2501-4.
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1111/j.1469-7998.1893.tb00001.x, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1111/j.1469-7998.1893.tb00001.xinstead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1016/j.ympev.2011.09.025, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1016/j.ympev.2011.09.025instead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1111/j.1474-919X.1973.tb01980.x, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1111/j.1474-919X.1973.tb01980.xinstead. - ^ a b c Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.3366/anh.2003.30.1.13, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.3366/anh.2003.30.1.13instead. - ^ Fuller, E. (2001). Extinct Birds (revised ed.). New York: Comstock. pp. 230–231. ISBN 0-8014-3954-X.
- ^ a b c Cheke and Hume (2008), p. 172.
- ^ Rothschild, W. (1907). Extinct Birds (PDF). London: Hutchinson & Co. p. 49.
- ^ Forshaw, J. M. (2006). Parrots of the World; an Identification Guide. Illustrated by Frank Knight. Princeton University Press. plate 23. ISBN 0-691-09251-6.
{{cite book}}: Unknown parameter|nopp=ignored (|no-pp=suggested) (help) - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1017/S0030605300020457, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1017/S0030605300020457instead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1017/S0030605300012643, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1017/S0030605300012643instead. - ^ a b Cheke and Hume (2008), p. 38.
- ^ Holyoak, D. T. (1971). "Comments on the extinct parrot Lophopsittacus mauritianus". Ardea. 59: 50–51.
- ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1071/MU973157, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1071/MU973157instead. - ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1111/j.1474-919X.1975.tb04187.x, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi=10.1111/j.1474-919X.1975.tb04187.xinstead. - ^ Hume, J. P.; R. P. Prys-Jones, R. P. (2005). "New discoveries from old sources, with reference to the original bird and mammal fauna of the Mascarene Islands, Indian Ocean" (PDF). Zoologische Mededelingen. 79 (3): 85–95.
{{cite journal}}: CS1 maint: multiple names: authors list (link)