The collared bush-robin or Johnstone's robin (''Tarsiger johnstoniae'') is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

in the family

Muscicapidae The Old World flycatchers are a large family, the Muscicapidae, of small passerine birds restricted to the Old World (Europe, Africa and Asia), with the exception of several vagrants and two species, bluethroat (''Luscinia svecica'') and north ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

, living in montane and subalpine forests. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN) has assessed it as a least-concern species.

Taxonomy

This species was described as ''Ianthia johnstoniae'' by William Robert Ogilvie-Grant in 1906: the specimens were collected by Walter Goodfellow on Yushan (Mount Morrison). It has also been included in the genus '' Luscinia''. The species' eponym is named after Marion A. Johnstone, a well-known aviculturist to whom Goodfellow previously sent a specimen of a lorikeet.

Description

The collared bush-robin is about long. The male and female are different. The male has a slate-black head with a white

supercilium The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head.Dunn and Alderfer (2006), p. 10 Also k ...

. The rufous upper breast, mantle and scapulars form a collar. The back is sooty-black, the wings are black and brownish-black, and the tail is black. The lower breast is buffish-yellow, and the belly varies from grey-white to buffish-olive. The beak and legs are black. The female has a less distinct supercilium. The upperparts are mostly dull olive-brown, and the wings and tail are dark brown. The underparts are variable. The throat and breast are warm brown, but the throat is sometimes blackish, and the breast can be pale yellow or yellowish-olive. The juvenile bird can be distinguished from the female by its pale buff streaks and spots.

Distribution and habitat

Endemic to Taiwan, this robin's habitat is montane and subalpine forests, usually at elevations of and sometimes above the

tree line The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low ...

. It descends to lower elevations in winter. It lives in undergrowth of coniferous forests with shrubs and bamboo. It can also be seen in parks and along roads.

Behaviour

The collared bush-robin is often seen in pairs and also singly. It catches insects by striking from perches, and it also forages for invertebrates on the ground and in low plants. Its calls include ''tuc'' notes with ''pi'' notes in between, a low ''grruit'', and a combination of piping and grating notes. It sings from a perch, giving a series of phrases each consisting of two or three high-pitched, sibilant notes. Breeding occurs from March to August, and there are two broods per year. A territory is defended by the male and female. The female builds a cup nest made of plants and lays two to three eggs. The collared bush-robin sometimes hybridises with subspecies ''formosanus'' of the white-browed bush robin.

Status

Suspected to have a stable population, this species has been assessed by the IUCN as being of

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

References