Vanikoro spectacle bird

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Vanikoro spectacle bird
Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Sylvioidea
Family : Spectacled birds (Zosteropidae)
Genre : Zosterops
Type : Vanikoro spectacle bird
Scientific name
Zosterops gibbsi
Dutson , 2008

The Vanikoro Spectacled Bird ( Zosterops gibbsi ) is a little researched bird species from the family of the spectacled birds (Zosteropidae). It is endemic to Vanikoro Island in the Santa Cruz Islands . The taxon was only described in 2008. The species epithet honors the British naturalist David Gibbs , who discovered the species in 1994.

features

The Vanikoro Spectacled Bird was described on the basis of three adult specimens (two females and one male), which were collected by Guy Dutson in 1997 and are now in the Walter Rothschild Zoological Museum in Tring . The length of the elongated wing between the wing bow and wing tip is 67 to 69 millimeters. The tail has a length of 42 to 43 millimeters. The barrel length is 19 millimeters. The Vanikoro spectacle bird reaches a beak length of up to 16 millimeters. In addition to the clumsier Lifu-eyeglass bird ( Zosterops inornatus ), whose bill can be up to 18.5 millimeters long, it is one of the Zosterops species with the longest beaks.

The top of the head and the top are monochrome olive-green with a slight bronze-colored wash on the upper tail covers. The beak is pitch black with a light horn colored base of the lower beak. The iris is rich reddish orange. The eyes are surrounded by a powder gray, featherless eye ring. The light gray reins are sparsely feathered. The legs are bright orange. The toes are brightly sand-colored. The flight feathers are gray-brown and the control feathers are dark gray-brown with a slightly lighter olive-green outer border. The umbrella feathers and the arm wings have narrow olive-green outer hems. The wings of the hand have narrow olive-yellow outer hems. The throat, chest and middle of the abdomen are olive yellow with a light yellow wash on the chin. The flanks are a little darker. The under tail-coverts and the inner edges of the wing feather undersides are silvery.

A juvenile specimen observed in the field resembled the adult birds. The legs were washed out lighter pink and orange. The base of the beak was more blunt. The beak was dark horn-colored with a light yellow tip. The featherless skin around the eyes was more prominent and the plumage was generally duller.

The range of sound utterances includes a low , humming vruh , which is sometimes repeated several times in quick succession and varied in length and tone. From its geographically closest relative, the monochrome spectacle bird from the island of Nendo , the song of the Vanikoro spectacle bird differs in the longer, slower phrases with shorter, less melodic but more regular notes.

habitat

The Vanikoro Spectacled Bird was mainly observed in two habitats: in the thicket and in degraded secondary forests in the lowlands and in primary forests at medium altitudes above 350 meters. The species is particularly common at altitudes above 700 meters, where there are no clearings in the forests.

Way of life

The Vanikoro-Spectacled Bird goes in search of food in pairs or in groups of up to seven birds. Its diet consists of small fruits. He examines dead leaves or the underside of branches and uses vertical tree trunks as a seat guard.

Reproduction

Little is known about reproductive behavior. A nest with two nestlings was discovered on November 8, 1997. The young were mainly fed by one, two or three birds in the morning hours. This suggests that a helper is helping the parents with feeding. This form of cooperative young rearing has only been observed so far in the Mahé spectacled bird and in the mascarene spectacled bird . The bowl-shaped nest was made of tightly woven fine grass and other plant fibers in the fork of a small horizontal branch about four meters above the ground in a sparsely leafed tree. On November 19, the nest was already abandoned after it had not been checked for the previous eight days.

Existence and endangerment

The Vanikoro White-eye in 2009 by BirdLife International in the endangered species red list of the IUCN received in the category not compromised classified (least concern). The field observations showed that the species is common above 600 meters. The highland forests have so far been spared from clearing and degradation. Rats are present in the lowlands. However, the risk of endangerment from invasive species is currently difficult to assess.

discovery

When the Whitney South Sea Expedition stopped at Vanikoro in 1925 and 1927, no spectacled birds were detected on the island. In 1994 the British ornithologist David Gibbs visited the area around the village of Lavaka on Vanikoro, where he discovered a new species of spectacled bird. A formal description of the taxon was missing, however, since Gibbs did not succeed in catching a type specimen. During an expedition in November 1997, ornithologist Guy Dutson observed 17 specimens near Lavaka at an altitude of 800 meters. Three copies were collected, which served as the basis for the first scientific description in 2008.

literature

  • Guy Dutson: A new species of White-eye Zosterops and notes on other birds from Vanikoro, Solomon Islands. In: Ibis. 150, 4, 2008, ISSN  0019-1019 , pp. 698-706.
  • Joseph Del Hoyo, Andrew Elliot, David A. Christie (Eds.): Handbook of the Birds of the World. Volume 13: Penduline-Tits to Shrikes. Lynx Edicions, Barcelona 2008, ISBN 978-84-96553-45-3 .

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