Petroica de Tasmania

Identificación

Measuring from 14-16.5 centimetres in length, and weight around 27 grams, the dusky robin lacks the bright colours of its robin relatives. The bird has short, slender bill and a moderately long tail, and it is much larger than other Petroicidae that occur in Tasmania. It is almost impossible to differentiate male from female in the field. They have no seasonal variation nor sexual dimorphism. <p>However, there are large, noticeable differences between adults and juvenile dusky robins.<p>The juvenile dusky robin is black-brown on the top of its head and side of its neck, the side of the head is dark-brown in colour and heavily streaked off-white. Its chin and throat are mostly light grey-brown. The upper body is dark brown and heavily streaked off-white. The upper tail is also dark brown with indistinct pale pinkish-buff tip and edges. The wings are mostly dark brown, with prominent white or off-white to brownish-white tips or drosethorns to most coverts. There're also narrow and indistinct off-white strips along leading edges of the wings and an inconspicuous off-white to brownish-white central wing-bar across the bases of the remiges. The under body is mostly light grey-brown, diffusely streaked or mottled off-white and black-brown. The under-tail cover is light grey-brown with narrow off-white streaks. The bill is grey-black, the gape is yellow and puffy, iris are dark brown, with pale brown-grey legs and feet.<p>The adult dusky robin has brown feathers on the top of its head and on the sides of its neck. The distinctive lore and narrow dark-brown line extending from behind the eye to the ear-coverts, forming a dark eye-stripe, bordered above by cream supercilious that extends from the base of the bill and peters out above the rear ear-coverts. Below the eye-stripe, ear-coverts, dark brown streaked cream which are more coarsely below the lore, grading to off-white to very pale grey-brown chin and throat. The upper body is uniformly brown. The upper tail is dark brown with fine white sides and tip, folded wings are dark brown with narrow and indistinct white strip along the leading edge of the wings. The underbody is mostly light grey-brown, with greyish suffusion at the breast and diffuse off-white tips to undertail-coverts. The under tail is brown with fine white sides and tip. The underwing is mostly dark brown, with brown remiges but patterned similar to upper wing.

Taxonomía

The dusky robin was described by the French zoologists Jean Quoy and Joseph Gaimard in 1832 based on a specimen that the authors mistakenly believed had been collected in "le port du Roi-Georges, à la Nouvelle-Hollande", but that had actually come from Tasmania. <p>They coined the binomial name, Muscicapa vittata. It was known for many years as Petroica vittata before being placed in its current genus Melanodryas. Two subspecies are recognised, one on the Tasmanian mainland and the other on King Island. 'Stump robin' was a name given to it by early settlers from its habit of sitting on stumps or posts. Other local names include 'wood robin' and 'sad robin'.<p>The Australian robins were classified for a time in the Old World flycatcher family Muscicapidae or the whistler family Pachycephalidae, before being placed in their own family Petroicidae, which is a compact built, rounded head, a short, straight bill and rounded wingtips robin. Sibley and Ahlquist's DNA-DNA hybridisation studies placed the robins in a Corvida parvorder comprising many tropical and Australian passerines, including pardalotes, fairy-wrens, honeyeaters, and crows. However, subsequent molecular research (and current consensus) places the robins as a very early offshoot of the Passerida, or "advanced" songbirds, within the songbird lineage.

Nombre científico

Melanodryas vittata

Autoridad

(Quoy & Gaimard, 1832)

Orden

Passeriformes

Familia

Petroicidae

Género

Melanodryas

Distribución y hábitat

The dusky robin is endemic to Tasmania, where it is widespread. They have an open habitat, ranging from sea level to 1,200m above sea level. They usually occur in dry sclerophyll forest, but can also be found in coastal heathland, sedge land and Button Grass plains. They, however, favour ecotones, between forests and clearings or recently burnt area.

Migración

Especie residente

Comportamiento

Patrón migratorio: Especie residente.

Conservación

Tendencia poblacional: en declive.

Tendencia poblacional

en declive