Broad-billed parrot: Difference between revisions
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Many endemic Mascarene birds are derived from South Asian ancestors, including the [[Dodo]], and it has been proposed that it is true for the parrots as well. Sea levels were lower during the [[Pleistocene]], so it was possible for species to "island hop" to the isolated islands. Of the about eight endemic Mascarene parrot species, all but the [[Mauritius Parakeet]] have gone extinct. In spite of many of them being poorly known, fossil remains show that they shared features such as enlarged heads and jaws, reduced [[pectoral]] elements, and robust leg elements. [[Julian Hume]] has suggested their common origin is within the [[Psittaculini]] [[Evolutionary radiation|radiation]], based on [[morphology (biology)|morphological]] features, and the fact that ''[[Psittacula]]'' parrots have managed to colonise many isolated islands in the Indian Ocean.<ref name="Mascarene Parrots">Hume, Julian Pender (2007): Reappraisal of the parrots (Aves: Psittacidae) from the Mascarene Islands, with comments on their ecology, morphology, and affinities. ''[[Zootaxa]]'' '''1513''': 1–76 [http://www.mapress.com/zootaxa/2007f/z01513p076f.pdf PDF abstract].</ref> This group may have invaded the area several times, as many of the species were so specialised that they may have diverged on [[hot spot islands]] before the Mascarenes emerged form the sea.<ref name="Lost Land"/> However, a 2012 genetic study showed that the [[Mascarene Parrot]] was nested among the subspecies of the [[Lesser Vasa Parrot]] from Madagascar and nearby islands, and was therefore not related to the ''Psittacula'' parrots.<ref>{{Cite doi|10.1016/j.ympev.2011.09.025}}</ref> This is surprising, due to its anatomical similarities with other Mascarene parrots that are believed to be Psittaculines.<ref name="Extinct Birds"/> |
Many endemic Mascarene birds are derived from South Asian ancestors, including the [[Dodo]], and it has been proposed that it is true for the parrots as well. Sea levels were lower during the [[Pleistocene]], so it was possible for species to "island hop" to the isolated islands. Of the about eight endemic Mascarene parrot species, all but the [[Mauritius Parakeet]] have gone extinct. In spite of many of them being poorly known, fossil remains show that they shared features such as enlarged heads and jaws, reduced [[pectoral]] elements, and robust leg elements. [[Julian Hume]] has suggested their common origin is within the [[Psittaculini]] [[Evolutionary radiation|radiation]], based on [[morphology (biology)|morphological]] features, and the fact that ''[[Psittacula]]'' parrots have managed to colonise many isolated islands in the Indian Ocean.<ref name="Mascarene Parrots">Hume, Julian Pender (2007): Reappraisal of the parrots (Aves: Psittacidae) from the Mascarene Islands, with comments on their ecology, morphology, and affinities. ''[[Zootaxa]]'' '''1513''': 1–76 [http://www.mapress.com/zootaxa/2007f/z01513p076f.pdf PDF abstract].</ref> This group may have invaded the area several times, as many of the species were so specialised that they may have diverged on [[hot spot islands]] before the Mascarenes emerged form the sea.<ref name="Lost Land"/> However, a 2012 genetic study showed that the [[Mascarene Parrot]] was nested among the subspecies of the [[Lesser Vasa Parrot]] from Madagascar and nearby islands, and was therefore not related to the ''Psittacula'' parrots.<ref>{{Cite doi|10.1016/j.ympev.2011.09.025}}</ref> This is surprising, due to its anatomical similarities with other Mascarene parrots that are believed to be Psittaculines.<ref name="Extinct Birds"/> |
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In 1973, D. T. Holyoak described a subfossil Mauritian parrot as a smaller species of ''Lophopsittacus'', ''L. |
In 1973, D. T. Holyoak described a subfossil Mauritian parrot as a smaller species of ''Lophopsittacus'', ''L. bensoni'', based on remains collected by Etienne Thirioux in the early 20th century.<ref>{{Cite doi|10.1111/j.1474-919X.1973.tb01980.x}}</ref> In 2007, Julian Hume reclassified it as a species of ''Psittacula'' instead, correlated the fossils with 17th and 18th century descriptions of small grey parrots on Mauritius and [[Réunion]], and named it [[Thirioux's Grey Parrot]].<ref name="Mascarene Parrots"/> |
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===Identification and etymology=== |
===Identification and etymology=== |
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Revision as of 22:49, 25 August 2012
| Broad-billed Parrot | |
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| Sketch of two Broad-billed Parrots in the 1601 journal of the ship Gelderland | |
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| Genus: | Lophopsittacus Newton, 1875
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| Species: | L. mauritianus
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| Binomial name | |
| Lophopsittacus mauritianus (Owen, 1866)
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The Broad-billed Parrot, Raven Parrot or Indian Raven (Lophopsittacus mauritianus) is a large, extinct parrot which was endemic to the Mascarene island of Mauritius east of Madagascar in the Indian Ocean. Its affinities are unclear, but it has been classified as a member of Psittaculini along with other Mascarene parrots.
It had a proportionally large skull and beak, and a distinct crest of feathers on the front of the head. It exhibited the largest cranial sexual dimorphism known in any parrot. It is believed to have been a weak flier, but not flightless. Its exact colouration is unknown, but a contemporary description indicates it had a blue head, a greyish or blackish body, and perhaps a red beak. It had large jaws to crack hard seeds open, comparable to those of the Hyacinth Macaw.
The Broad-billed Parrot was first referred to as "Indian Raven" in a Dutch ship's journals from 1598 onwards, and 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 of the bird, which matched both. It became extinct in the 17th century, due to deforestation and predation by humans and the invasive species they brought.
Taxonomy and evolution
The affinities of the Broad-billed Parrot are undetermined. Edward Newton and Hans Gadow found it to be closely related to the Rodrigues Parrot due to their large jaws and other osteological features, but retained them in separate genera due to the distinct crest of the former.[2]
Many endemic Mascarene birds are derived from South Asian ancestors, including the Dodo, and it has been proposed that it is true for the parrots as well. Sea levels were lower during the Pleistocene, so it was possible for species to "island hop" to the isolated islands. Of the about eight endemic Mascarene parrot species, all but the Mauritius Parakeet have gone extinct. In spite of many of them being poorly known, fossil remains show that they shared features such as enlarged heads and jaws, reduced pectoral elements, and robust leg elements. Julian Hume has suggested their common origin is within the Psittaculini radiation, based on morphological features, and the fact that Psittacula parrots have managed to colonise many isolated islands in the Indian Ocean.[3] This group may have invaded the area several times, as many of the species were so specialised that they may have diverged on hot spot islands before the Mascarenes emerged form the sea.[4] However, a 2012 genetic study showed that the Mascarene Parrot was nested among the subspecies of the Lesser Vasa Parrot from Madagascar and nearby islands, and was therefore not related to the Psittacula parrots.[5] This is surprising, due to its anatomical similarities with other Mascarene parrots that are believed to be Psittaculines.[6]
In 1973, D. T. Holyoak described a subfossil Mauritian parrot as a smaller species of Lophopsittacus, L. bensoni, based on remains collected by Etienne Thirioux in the early 20th century.[7] In 2007, Julian Hume reclassified it as a species of Psittacula instead, correlated the fossils with 17th and 18th century descriptions of small grey parrots on Mauritius and Réunion, and named it Thirioux's Grey Parrot.[3]
Identification and etymology
The earliest known descriptions of the Broad-billed Parrot were made 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 Dodo. The Dutch sailors who visited Mauritius referred the Broad-billed Parrots as "Indian Ravens" or "Indian Crows", which lead to confusion when their journals were subsequently studied by early naturalists.[4] The sailors may have referred to it as "Indian Raven/Crow" due to a harsh call, behavioural traits, or simply dark plumage, which could have reminded them of such birds. Although the Dutch and French also referred to South American macaws as "Indian Ravens" during the 17th century, the name was also used for hornbills by the Dutch, French, and English in the East Indies.[3] Sir Thomas Herbert referred to the bird as "Cacatoes" (Cockatoo) in 1634, and described them as "birds like Parrats, fierce and indomitable", but naturalists did not realise it referred to the same bird.[4] Even after fossils of a parrot matching the descriptions were discovered, some writers continued to argue that the "Indian Raven" was a hornbill, but no such remains have ever been found, and hornbills are not found on any oceanic islands, apart from an extinct species from New Caledonia.[3]
The first known physical remain of the Broad-billed Parrot was a subfossil mandible, collected along with the first batch of Dodo bones found in the Mare aux Songes swamp.[6] Richard Owen, who also coined the vernacular name, described the mandible in 1866 and identified it as belonging to a large parrot, naming it Psittacus mauritianus.[8] In 1868, Hermann Schlegel identified an illustration in the 1601 journal of the Dutch East India Company ship Gelderland (attributed to the artist Joris Laerle) as depicting the parrot described by Owen, and connected them to the old journal descriptions. On this basis, Alfred Newton coined the new genus name Lophopsittacus for the bird.[9] "Lophos" is the Greek word for crest, in reference to its frontal crest, and "psittacus" means parrot.[3]
Description
The Broad-billed Parrot possessed a distinct frontal crest, evidenced by contemporary sketches as well as ridges on the cranium that show it was firmly attached, and, unlike in members of Cacatuinae, unable to be raised and lowered in life.[3] Examination of the 1601 Gelderland sketch shows that the crest was attached to the front of the head at the base of the beak, and depicted as loose, rounded feathers. The sketch also shows long primary covert feathers, large secondary feathers, and a slightly bifurcated tail.[10]
The following account by Reyer Cornelisz from 1602 is the only contemporary mention of size differences, and may refer to the sexes:
In this country occur Tortoises, Wallichvogels [Dodos], Flamingos, Geese, Ducks, Field-hens, large and small Indian Crows [Broad-billed Parrots], Doves, some of which have red tails (by eating which many of the crew were made sick), grey and green Parrots with long tails, some of which were caught.[11]
Furthermore, difference in size of fossil specimens and on the 1601 sketch indicate that the sexes were size dimorphic. The males were largest, measuring approximately 55–65 cm and the females 45–55 cm. The difference between male and female skulls is the largest among parrots, but the differences in the postcranial skeleton are less pronounced. Both sexes had disproportionally large heads and jaws. Unlike other Mascarene parrots, the skull was flattened.[3]
There has been some confusion over its colouration.[12] The report of the 1589 Van Neck 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.[4]
The last account, and the only mention of specific colours, is by Johann Christian Hoffman in 1673–5:
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’.[4]
The head was evidently blue, and the beak may have been red as is diagnostic for 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 the Gelderland journal described the bird as entirely blue-grey, but subsequent examination of the journal has only revealed a description of the Dodo. The distinctively drawn facial mask may represent a colour.[10][13]
Behaviour and ecology
Little is known about the behaviour of the Broad-billed Parrot. In other parrots with large sexual dimorphism in beak size, the sexes prefer food of different sizes, the males use their beaks in rituals, and the sexes have specialised reproductive roles. The large cranial size difference between male and female may therefore have affected the ecology of each sex, but it is impossible to determine how today.[3]
Though it perhaps fed on the ground and was a weak flier, its tarsometatarsus was short and stout, indicating that it had arboreal characteristics. The parrot was recorded on the leeward, dry side of Mauritius, which was 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. The Broad-billed Parrot perhaps nested in tree cavities or rocks, like the Cuban Amazon.[3]
The following description by Jacob Granaet from 1666 states it inhabited the forest, 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.[4]
It has been suggested that the Broad-billed Parrot was flightless, inferred from the apparent short wings and large size shown in the 1601 Gelderland sketch. Examination of the original drawing has shown that the underlying pencil sketch shows the wings are not particularly short. The wings appear broad, which is commonly associated with forest-adapted species, and the alula appears to be large, a feature of slow-flying birds. Its sternal keel was reduced, but not enough to prevent flight, the adept flying Cyanoramphus parrots also have reduced keels, and even the flightless Kakapo, with its nearly obsolete keel, is capable of gliding.[3] Furthermore, one account mentions it could fly, although with difficulty, and the first published illustration shows the bird on top of a tree, unlikely for a flightless bird.[10]
Masauji Hachisuka suggested the Broad-billed Parrot was nocturnal like the Kakapo and the Night Parrot, two extant, ground-dwelling parrots. However, contemporary accounts do not suggest this, and the orbits are of similar size to those of other large, diurnal parrots.[3]
Many other of the endemic species of Mauritius went extinct after the arrival of man, so the ecosystem of the island is heavily damaged, and hard to reconstruct. Before humans arrived, Mauritius was entirely covered in forests, but very little remains today due to deforestation.[14] The surviving endemic fauna is still seriously threatened.[15] 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 went extinct in both islands.[4]
Diet
Species morphologically similar to the Broad-billed Parrot, such as the Hyacinth Macaw and the Palm Cockatoo, may provide insight into its ecology. Anodorhynchus macaws eat very hard palm nuts and are habitual ground dwellers.[3] The macaws are believed to have been depended on the now extinct South American megafauna to eat fruits and excrete their seeds, but have since switched to domesticated cattle performing this function. The Palm Cockatoo also feeds on undigested seeds from Cassowary droppings.[3] It has been suggested 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.[4] There are many types of palms and palm-like plants on Mauritius which produce hard seeds that may have been eaten by the Broad-billed Parrot, including those of Latania loddigesii, Mimusops maxima, Sideroxylon grandiflorum, Diospyros egrettorium, and Pandanus utilis.[3]
D. T. Holyoak claimed the mandible of the Broad-billed Parrot was weakly constructed, based on x-radiographs, and suggested it would have fed on soft fruits rather than hard seeds.[3] However, the "strong jawed" parrot genera he compared it to actually have weak jaws, and 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.[16]
Extinction
The Broad-billed Parrot was ready prey for sailors who visited Mauritius due to its weak flight ability, large size, and possibly confiding nature. The nests would also have been extremely vulnerable to predation by introduced pigs, Crab-eating Macaques, and rats. It is believed to have gone extinct by the 1680s, when the palms it may have specialised in were harvested on a large scale.[3]
Unlike other parrot species, which were often taken as pets by sailors, there are no records of Broad-billed Parrots having been transported from Mauritius, perhaps due to the stigma associated with Ravens.[3] But they would not have survived such a journey, if they refused to eat anything but seeds.[4]
References
- ^ Template:IUCN
- ^ 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. - ^ a b c d e f g h i j k l m n o p q r Hume, Julian Pender (2007): Reappraisal of the parrots (Aves: Psittacidae) from the Mascarene Islands, with comments on their ecology, morphology, and affinities. Zootaxa 1513: 1–76 PDF abstract.
- ^ a b c d e f g h i Cheke, A. S.; Hume, J. P. (2008). Lost Land of the Dodo: an Ecological History of Mauritius, Réunion & Rodrigues. T. & A. D. Poyser. ISBN 978-0-7136-6544-4.
- ^ 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. - ^ a b Hume, J. P.; Walters, M. (2012). Extinct Birds. A & C Black. ISBN 140815725X.
- ^ 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. - ^ 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. - ^ 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. - ^ 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.
- ^ Fuller, Errol (2001). Extinct Birds (revised ed.). Comstock. pp. 96–97. ISBN 0-8014-3954-X.
- ^ Rothschild, Walter (1907). Extinct Birds (PDF). London: Hutchinson & Co.
- ^ 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. - ^ 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)