Jerdon's Courser

Identificazione

It is an unmistakable compact courser, with two brown breast-bands. It has a yellow base to the black bill, a blackish crown, broad buff supercilium, and an orange-chestnut throat patch. A narrow white crown stripe runs on top of the head. In-flight it shows a mostly black tail and a prominent white wing bar. It is crepuscular and vocal at dawn and dusk with a series of staccato Twick-too...Twick-too... Twick-too or yak-wak.. yak-wak calls. The notes are repeated at the rate of about 1 per second and uttered 2 to 16 times and several birds in the vicinity may join in the calling.<p>Jerdon described the Telugu name of the species as Adavi wuta-titti meaning "Jungle empty-purse". This name may however have been in error since Salim Ali and Hugh Whistler found villagers mystified by the name when they searched for the species near Borgampad and Nelipaka during the Hyderabad state survey of 1931. Recent researchers have noted the local name as Kalivi kodi.<p>The only known egg of the bird is preserved at the Zoology Museum, University of Aberdeen. The egg was collected by Ernest Gilbert Meaton, a vet working at Kolar Gold Fields, in the year 1917.

Tassonomia

The species was first collected by Thomas C. Jerdon from somewhere in the Eastern Ghats. The specimen was presented to the Asiatic Society of Bengal where the curator, Edward Blyth described it, naming it as Macrotarsius rhinoptilus. These collections were moved to the Indian Museum in 1866 following a financial crisis. Some specimens had been mounted and exhibited for the public but John Anderson moved the type specimens for safe storage in 1872. The type specimens used by Blyth were catalogued but the specimen used by Blyth was already missing. A second catalogue by W.L. Sclater in 1892 also failed to list the specimen. The type specimen is therefore presumed lost. A second specimen collected by Jerdon was obtained by Strickland and is now in the collection of the Cambridge University. This specimen was examined by Strickland who used the new genus and combination, Rhinoptilus bitorquatus. The label written by Alfred Newton notes the location as "Madras" and date as 1846. During this period Jerdon is thought to have received specimens from near Nellore or Cuddapah. A third specimen in Jerdon's collection was acquired by Thomas Campbell Eyton and then to Henry Baker Tristram, and the specimen is now at National Museums Liverpool. Several other specimens exist in collections but a neotype, replacement for the type specimen, has not been suggested.

Nome scientifico

Rhinoptilus bitorquatus

Autorità

(Blyth, 1848)

Ordine

Caradriformi

Famiglia

Glareolidae

Genere

Rhinoptilus

Areale e habitat

It is endemic to southern India, where it is principally known from southern Andhra Pradesh. It has an extremely limited geographical range being known from the Godaveri river valley near Sironcha and Bhadrachalam, and from the Cuddapah and Anantpur areas in the valley of the Pennar River. An egg, probably collected within 100 km of Kolar in 1917, was positively identified as belonging to this species using DNA sequence comparison. It is mostly active at dusk and during the night. It was first recorded in the mid 19th century; it was then considered to be extinct for more than 80 years, until it was rediscovered in 1986 at Cuddapah District, Andhra Pradesh. In Maharashtra it was reported at “24 km east of Sironcha, near the Godavari river, three birds, undated (Blanford 1867, 1869), and sometime in the 20-year period before 1935 (D’Abreu, 1935)”. The species was known from specimens collected at a few locations in eastern peninsular India and the currently known population is extremely restricted in range. Studies in this region using sand strips to detect footprints suggest that their preferred habitat has tall bushes at a density of 300 to 700 per hectare.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione