Tuesday 10 August 2021

Newton’s Parakeet "Psittacula exsul" (A. Newton)

 OTHER NAME - Rodrigues Parakeet.

DESCRIPTION Length 40 cm.

Newton’s Parakeet Presumably green and blue morphs existed, and mention is made in an early account by Julien Tafforet of a red alar patch being present in the adult male of the green morph. Only two specimens survive, and both are of the blue morph. ADULT MALE General plumage greenish-blue with a greyish cast, paler on underparts; head noticeably darker and without greyish suffusion; fine black line from cere to eyes; chin black; broad black stripe across lower cheeks to sides of the neck, then becoming narrow and continuing up to nape; lower back and rump paler, lighter blue; primaries deep greenish-blue; tail dark greenish-blue above, greyish underside; upper mandible red, lower mandible black; iris yellow (Vandorous); legs grey. 1 specimen: wing 199 mm, tail 207 mm (abraded); exp. cul. 25 mm, tars. 22 mm. ADULT FEMALE Very faint black line on the forehead; black stripes not extending beyond sides of neck; crown suffused grey; upper mandible black. 1 specimen (type): wing 192 mm, tail 212 mm, exp. cul. 24 mm, tars. 23 mm. JUVENILES Undescribed. DISTRIBUTION Formerly occurred on Rodrigues, in the The Mascarene Islands.

 

STATUS The last records of Newton’s Parakeet were made in the 1870s, and presumably, it became extinct at about that time. Only two specimens were collected, the first being a female, which was collected in 1871 by George Jenner, the then magistrate on the island. This specimen was preserved in alcohol and given to Edward Newton, a colonial administrator on Mauritius, who in turn sent it to his brother, and it was used by Alfred Newton to describe the species (Newton and Newton 1876). The second specimen, a male, was shot by a local resident William Vandorous on 14 August 1875 and given to the assistant colonial secretary William Caldwell, who in turn forwarded it to Edward Newton. Caldwell remarked that he had seen several birds but could not get near one. Henry Slater, a naturalist who stayed on the island for three months in 1874, reported to Newton that on 30 September in that year he saw a single bird in a forest towards the southwestern end of the island (in Newton 1875).

It has been postulated that the male collected by Vandorous may have been the same bird seen by Slater in the previous year.

Hume (2007) documents account from early visitors to Rodrigues and note that although Newton’s Parakeets survived until the 1870s, they were in decline from the 1760s. François Leguat reported that they were abundant at the time of his stay on the island between 1691 and 1692: There is an abundance of green and blew Parrot's, they are of a middling and equal bigness; when they are young, their Flesh is as good as young Pigeons. Hunting and fishing were so easy for us, that it took away from the Pleasure. We often delighted ourselves in teaching the Parrots to speak, there being vast numbers of them. We carried one to Maurice Isle, which talked French and Flemish. A live bird was received by the naturalist Philibert Commersen on Mauritius during the 1770s, where it was described as a long-tailed, greyish-blue parrot with a black collar (in Oustalet 1897).

Hume notes that the parrots were still common when Julien Tafforet was on Rodrigues in 1726 but had become rare by the time of a visit in 1761 by Abbé Alexandre Pingré, a French astronomer who had come to monitor the transit of Venus, and he referred to their continued presence on the southern islets (translation by Hume): On the 19th at Isle Mombrani, the multitude of grey terns on our side served exactly as a parasol; they fly about our heads, in the manner more or less to ease the heat of the sun. In an additional premium to this, there were tropic birds and their eggs. There are also some frigates, some tratras, some perruches. After the visit by Pingré, there was severe deforestation on the island and an increase in numbers of free-roaming livestock. In 1843, a government surveyor Thomas Corby was sent to Rodrigues to ascertain the suitability of the land to support cattle and he noted that the western side of the island, although severely deforested, contained the best stands of palms and Pandanus screwpines. Corby also referred to the presence of many wild bullocks, pigs, great flights of guinea fowl and green parrots, indicating that Newton’s Parakeets remained fairly numerous, but they had become extremely scarce by 1871 when the first the specimen was received by Alfred Newton.

There were no records after the second specimen was collected in 1875, and Hume suggests that the last few survivors may have been wiped out by a devastating series of cyclones in the following year. HABITATS Newton’s Parakeets presumably frequented native forest, and extensive destruction of this habitat was a major factor in their decline and subsequent extinction. HABITS Leguat commented on the partiality of Newton’s Parakeets to the nuts of bois d’olive Cassine orientale and made mention of the bois du buis Fernelia buxifolia being a food tree for Newton’s Parakeets and for Leguat’s Parrot Necropsittacus rodericanus (in Hume 2007). Nothing is known of habits of Newton’s Parakeets, though they probably were similar to the habits of Mauritius Parakeets. SPECIMENS AVAILABLE Both specimens (18/Psi/67/h/1


 type and 18/Psi/67/h/2 [1]) are held in the Museum of Zoology at Cambridge University, UK. Mascarinus Lesson, Traité d’Orn., livr. 3, 1830, p. 188. Type, by tautonymy, Mascarinus madagascarensis Lesson = Psittacus mascarin Linnaeus.

The extinct species belonging to this monotypic genus was a midsized parrot with a large red bill and a moderately long, broadly rounded tail. Traditionally, it has been associated with the Psittaculini and, apart from plumage coloration, it resembles the Tanygnathus parrots from Southeast Asia. Alternatively, it has at times been linked with Coracopsis from Madagascar and the Comoros Archipelago, probably because of a the similarity in the brown plumage coloration, and it has been noted that Coracopsis and Mascarinus are the only parrots that naturally lack psittacin in their plumage (in Hume and van Grouw 2014). An extraordinary finding from molecular analyses that a cytochrome b sequence from mitochondrial DNA of Mascarinus is embedded in Coracopsis has been questioned on the basis that the mitochondrial DNA was extracted from the damaged type specimen (MNHN 211) and alternative hypotheses concerning the placement of Mascarinus were not considered (see Kundu et al. 2012; Joseph et al. 2012).

Molecular analyses of DNA extracted from the only other specimen (NMW 50.688) indicates that the previously obtained cytochrome b sequence probably is an artificial composite of partial sequences from two other parrot species and that Mascarinus is indeed part of the Psittacula diversification, placed close to P. eupatria and P. wardi (Podsiadlowski et al. 2017). I strongly support this finding and am of the opinion that all three extinct monotypic genera from the Mascarene Islands – Mascarinus, Necropsittacus, and Lophopsittacus – can be placed in Psittaculini. Mascarinus formerly occurred on Réunion, and possibly on Mauritius, in the Mascarene Islands. 


No comments:

Post a Comment