Australian Crake

Identificazione

The Australian crake measures 19–23 cm (7.5–9.1 in) in length, weighs 55–70 g (1.9–2.5 oz) and has a wingspan of 27–33 cm (11–13 in). It is similar in appearance and behaviour to Baillon's crake (Porzana pusilla), but the Australian crake is stockier and darker overall and lacks the distinctive barred undertail of the Baillon's crake (Porzana pusilla). The Australian crake has a sooty face with steel-blue/dark grey breast, belly and throat. Brown upperparts, including the crown, are streaked black and white, with barred black and white flanks. Shorter undertail coverts are black and longer undertail coverts are white, forming a distinctive upside down V when tail is cocked. The outermost primaries have a distinctly white leading edge that is visible during flight. The bill is yellow-green with red base to upper mandible and measures 1.8–2.1 cm (0.71–0.83 in). Legs and feet are also yellow-green and the iris is red. While Gould asserted in The Birds of Australia (Gould) that "the sexes present so little difference in colour, that they are only to be distinguished by dissection", it can be noted that the female is slightly smaller and paler than male with a brown stripe across upper lores and more defined white spots on breast and neck. Immature birds are paler again with white fringed plumage on belly and breast appearing like muted barring. Juveniles are similar to adults but lack the steel-blue/dark grey plumage and instead have brown and white speckled underparts, as well as a brown iris and no red on bill. Chicks have very plumulaceous black feathers with a deep green hue and a distinctive, red blaze to base of upper mandible.

Tassonomia

The Australian crake was formally described in 1843 by the English ornithologist John Gould and given the binomial name Porzana fluminea. He specified the type locality as New South Wales. The specific epithet is from Latin flumineus meaning "riverine" (from flumen meaning "river"). The species is monotypic: no subspecies are recognised.

Nome scientifico

Porzana fluminea

Autorità

Gould, 1843

Ordine

Gruiformi

Famiglia

Rallidae

Genere

Porzana

Areale e habitat

Endemic to Australia, the Australian crake can be found throughout southeast and Western Australia. It is less common in Tasmania and tropical areas of northern Australia. The Australian crake lives in both coastal and inland habitats in freshwater, brackish, marine and terrestrial environments where it prefers densely vegetated areas of marshes, swamps, estuaries and saltmarshes that support lignum, chenopods, rushes and sedges. Distribution and movement is dependent on water conditions, so following periods of high rainfall, range can extend inland to areas like Alice Springs/Mparntwe.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Sebbene la schiribilla australiana sia classificata a rischio minimo, la perdita dell'habitat, gli animali invasivi e quelli domestici inselvatichiti, l'agricoltura, il pascolo del bestiame e i cambiamenti climatici rappresentano minacce per la specie. La conservazione delle zone umide è fondamentale per la sua sopravvivenza.

Tendenza della popolazione

unknown