The Mascarene grey parakeet, Mauritius grey parrot, or Thirioux's grey parrot (Psittacula bensoni), is an extinct species of parrot which was endemic to the Mascarene Islands of Mauritius and Réunion in the western Indian Ocean. It has been classified as a member of the tribe Psittaculini, along with other parrots from the Islands. Subfossil bones of the Mascarene grey parakeet found on Mauritius were first described in 1973 as belonging to a smaller relative of the broad-billed parrot in the genus Lophopsittacus. Apart from their size, the bones were very similar to those of other Mascarene parrots. The subfossils were later connected with 17th- and 18th-century descriptions of small grey parrots on Mauritius and Réunion, together with a single illustration published in a journal describing a voyage in 1602, and the species was instead reassigned to the genus Psittacula. The Mascarene grey parakeet was grey, had a long tail, and was larger than other species of the genus Psittacula, which are usually green. The grey parrots were said to be easy to hunt, as the capture of one would result in its calling out to summon the whole flock. They were also considered to be crop pests, and being such easy prey meant that they were extensively hunted. Coupled with deforestation, this pushed them into extinction. This had happened by the 1730s on Réunion and by the 1760s on Mauritius.
Taxonomy In 1973, English ornithologist Daniel T. Holyoak described some small parrot bones that he had discovered among a collection of broad-billed parrot (Lophopsittacus mauritianus) subfossils in the Zoology Museum of Cambridge University. These remains had been collected in the early 20th century by French amateur naturalist Louis Etienne Thirioux, who had found them in a cave on Le Pouce mountain, on the Mascarene Island of Mauritius. They were placed in the zoology museum by 1908. Apart from their size and robustness, Holyoak did not find the bones to be distinct from those of the Mascarene parrot genera Lophopsittacus, Mascarinus (the Mascarene parrot), Necropsittacus (the Rodrigues parrot), and Psittacula (which had two or three other species inhabiting the Mascarene Islands). Because of their similarities, Holyoak considered all these genera to be closely related.
Holyoak provisionally placed the new species in the same genus as the broad-billed parrot, naming it Lophopsittacus bensoni; the name honours English ornithologist Constantine W. Benson, for his work on birds from the Indian Ocean, and in classifying bird collections at Cambridge. Holyoak also mentioned the possibility that the remains could represent a small subspecies of Necropsittacus or a wide-beaked form of Mascarinus, but maintained that they were best considered as belonging to a distinct species. The holotype specimen is a mandibular symphysis, with the specimen number UMZC 577a. Other known remains include upper mandibles, a palatine bone, and tarsometatarsi. The species has since been excavated from the Mare aux Songes swamp on Mauritius, from which subfossils of most of the other endemic bird species have been identified as well. Old, vague accounts of several different now-extinct Mascarene parrots have created much confusion for the scientists who subsequently examined them. In 1967, American ornithologist James Greenway speculated that 17th- and 18th-century reports of then-unidentified grey parrots on Mauritius referred to the broad-billed parrot. In 1987, English ecologist Anthony S. Cheke correlated the L. bensoni subfossils with the grey parrots reported from Mauritius and Réunion, which had previously been ignored, or considered references to broad-billed parrots. Further study of contemporary accounts indicates that the broad-billed parrot was not grey, but had multiple colours. In 2007, the English palaeontologist Julian P. Hume reclassified L. bensoni as a member of the genus Psittacula, as he found it to be generically distinct from Lophopsittacus, but morphologically similar to the Alexandrine parakeet (Psittacula eupatria). Hume also pointed out that an engraving accompanying the 1648 published version of Dutch captain Willem van West-Zanen's journal may be the only definite depiction of this species. The engraving shows the killing of dodos (depicted as penguin-like), a dugong, and parrots on Mauritius in 1602; the depicted method of catching parrots matches that used on Mascarene grey parakeets according to contemporary accounts. That the parrots were grey was mentioned in the journal's text but not in the caption of the engraving. Hume coined the new common name "Thirioux's grey parrot" in honour of the original collector. The IOC World Bird List instead used the common name "Mascarene grey parakeet". The population of grey parrots described from the island of Réunion (referred to as Psittacula cf. bensoni by Hume) is thought to have been conspecific with that on Mauritius. Until subfossils of P. bensoni are found on Réunion, it cannot be confirmed whether the grey parrots of the two islands belonged to the same species. In the 1860s, French naturalists Charles Coquerel and Auguste Vinson suggested these could have been parrots of the genus Coracopsis, but fossils of neither that genus nor Psittacula have ever been found on Réunion. Whilst Coracopsis parrots are known to have been introduced to that island in the 1700s, a population did not become established. While no live or dead Mascarene grey parakeets are known with certainty to have been exported, Hume has suggested that a brown parrot specimen—once housed in Cabinet du Roi but now lost—may have been a discoloured old Mascarene grey parakeet, or perhaps a lesser vasa parrot (Coracopsis nigra). This specimen was described by French naturalist Comte de Buffon in 1779. Cheke and Hume suggested in 2008 that Mascarene grey parakeets did not reach Europe because they were considered unimpressive or had too specialised a diet.
Evolution
… excerpt ends here. Continue reading the full article.
