Jan 2, 2019

7 pay na pagar ma sudharo thayo see 1/1/2019 no official paripatra

7 pay na pagar ma sudharo thayo see 1/1/2019 no official paripatra


Aaj ka gyan

The Australian raven was first described by Nicholas Aylward Vigors and Thomas Horsfield in 1827, when they reported George Caley's early notes on the species from the Sydney district.[2] Its specific epithet coronoides "crow-shaped" is derived from the Greek corone/κορόνη "crow" and eidos/είδος "shape" or "form".[3] The two naturalists regarded the Australian raven as very similar in appearance to the carrion crow (C. corone) of Europe,[4] though they noted it was larger with a longer bill. They did not give it a common name.[2] The location where the type specimen was collected is not recorded, but thought to be in the Parramatta district.[5]Christian Ludwig Brehm described Corvus affinis in 1845,[6] later determined to be this species.[7] In his 1865 Handbook to the Birds of AustraliaJohn Gould recognised only one species of corvid in Australia, Corvus australis, which he called the white-eyed crow. He used Johann Friedrich Gmelin's 1788 name,[a] which predated Vigors and Horsfield's description.[10] In 1877 Richard Bowdler Sharpe recognised two species, but recorded that the feather bases of the type specimen of C. coronoides were white. He named C. coronoides as the "crow" and C. australis (as Corone australis) the "raven".[5]Scottish naturalist William Robert Ogilvie-Grant corrected this in 1912 after re-examining the type specimen, clarifying the species as C. coronoides (raven, and incorporating little and forest ravens) and C. cecilae (Torresian crow).[11]
Gregory Mathews described the western subspecies perplexus in 1912, naming it the southwestern crow and noting that it was smaller than the nominate subspecies. He called C. coronoides coronoides the eastern crow, listing its range as New South Wales, and described what is now the Australian crow as another subspecies, C. coronoides cecilae, calling it the north-western crow and recording its range as northwestern Australia. In the same work he listed the raven as Corvus marianae, with a type specimen from Gosford and listing its range as New South Wales. He listed the little raven and forest raven as subspecies.[12] Mathews had erected C. marianae in 1911 as the name after declaring Corvus australis Gould to be preoccupied;[13] French-American ornithologist Charles Vaurie acted as First Revisor under Article 24 of the International Code of Zoological Nomenclature (ICZN) Code and discarded C. australis as a junior homonym—in 1788, Gmelin had used the same binomial name to describe the black nunbird—to preserve the stability of the name.[14] This has been followed by later authors.[15]
German ornithologist Erwin Stresemannlumped all Australian corvids plus other species as far as India into a single species, C. coronoides, as he believed there was intergradation between all characteristics such as iris colour, colour of feather bases and plumage. This was hotly disputed by Mathews. The official RAOU checklist listed three species (Australian raven, Torresian crow and little crow), with the little raven recognised as a fourth species in 1967 and forest raven in 1970. Stresemann described C. difficilis in 1943 from a single specimen, now thought to have been an unusual Australian raven or an Australian raven/Torresian crow hybrid.

7 pay na pagar ma sudharo thayo see 1/1/2019 no official paripatra Rating: 4.5 Diposkan Oleh: SUGANITAM MS


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