Noisy Scrub-bird Atrichornis clamosus Scientific name definitions

Male c. 23 cm, 50–60 g; female c. 19·5 cm, 34 g. Rather small  , with short  rounded wings, long graduated tail  . Male  is mid-brown above, with fine, dark vermicu­lations on head, becoming broader barring on back  and extending to tail; wings faintly barred (variable); chin white or off-white; broad dark band (with prominent white feather tips in fresh plumage) extends from centre of throat  , sometimes from central chin, to upper breast, bordered by very broad white malar stripe  ; breast side dark greyish-brown; belly light buffish, flanks cinnamon with dusky barring, becoming more rufous towards rear, ventral area deep rufous  ; large eye dark brown; upper mandible dark grey, central ridge extends (sometimes with small hump) into forehead feathers, lower mandible pinkish and curving markedly down at gape; legs light brown or greyish. Female is noticeably smaller than male, lacks dark throatband, chin creamy, generally more buff below, grading to rufous posteriorly. Juvenile is more uniform, dark rufous-brown, greyer posteriorly.

Introduced on Bald I.

Western Australia in coastal and near-coastal areas between Two Peoples Bay and Cheyne Beach; reintroduced at several sites, including near Waroona (in Darling Range, S of Perth).

Dense scrub and the shrubby understorey of low forest; frequents gulleys, swamps, watercourses, and dense thickets on sides of hills, often around rocky outcrops. Sometimes also found in dense low heath. Most occupied sites have not been burned in more than a decade, sometimes for over a century. From near sea-level to 500 m.

Generally sedentary. Some males disperse up to 10 km from natal area, but many appear to remain in or near natal territory until they establish a new territory or successfully challenge another territorial male.

Eats a wide range of invertebrates  , but seems to prefer ants (Formicidae), beetles, spiders, orthopterans and various larvae. Vertebrates sometimes taken; small frogs (e.g. Crinia georgiana), skinks (Scincidae) and geckos (e.g. Phyllodactylus marmoratus) recorded as fed to nestling. Forages  mainly among deep leaf litter on the ground, also in rotting logs and debris and among stems and leaves of understorey plants. Pokes the bill into crevices and beneath leaves; lifts leaves with the head. Relies on flushing prey from litter and debris; does not scratch substrate.

Season Apr–Oct, during austral winter, most eggs laid in Jun. Male probably polygynous, plays no role in nest-building, incubation of eggs or brood-rearing, occupies permanent territory of c. 5 ha. Nest  dome-shaped, typically c. 18 cm high, 12·5 cm wide and 14 cm deep, with side entrance, constructed from grasses (mostly Lepidosperma and Anarthria, less commonly Gahnia, Agonis, Dryandra), inner layers quite tightly bound, outer layers looser, walls and floor up to 5 cm thick, bottom half of chamber lined with cardboard-like material made from wood pulp, often a small “hood” above entrance, usually also a loosely woven runway up to 20 cm long sloping up to entrance; typically c. 80 cm above ground, sometimes lower, and well hidden in clump of sedge or debris, occasionally in dense shrub or pile of debris. Clutch 1 egg; incubation period 5–6 weeks; chick brooded after each feed in early stages, daytime brooding ceases after c. 10 days but continues at night until fledging, chick fed with relatively large items (including small vertebrates) as it grows, female removes faecal sacs directly from cloaca of nestling; fledging period 3–4 weeks; after leaving nest, young remains close to its mother for up to 6 months. Success rates up to 90% in some populations; nests possibly preyed on by yellow-footed antechinus (Antechinus flavipes), possibly also by southern bush-rat (Rattus fuscipes). Female capable of breeding in first year, male at 2–3 years.

ENDANGERED. CITES I. Considered Vulnerable until uplisted to Endangered in 2012. Restricted-range species: present in South-west Australia EBA. Was considered extinct, but small population, of fewer than 100 individuals, rediscovered in 1961 at Mt Gardner, at Two Peoples Bay; latter area was soon thereafter designated a nature reserve. Was apparently reasonably common in 19th century, but by beginning of 20th century had become extremely rare; activities associated with European settlers (e.g. logging of forest, grazing by domestic stock, wholesale clearing of native vegetation for agriculture, and large-scale, intense wildfires) almost certainly responsible for the species’ rapid decline. Changes in fire regime following the disruption of Aboriginal fire management practice before the 1880s may have been a major factor. Over next 50 years, many comprehensive searches by ornithologists failed to find the scrub-bird, and it was believed to be extinct. Following its unexpected rediscovery in 1961, population at Two Peoples Bay increased steadily as a result of careful management, especially fire control, and from 1983 onwards individuals were captured there for reintroduction attempts elsewhere (after failure of captive-breeding programme in late 1970s); these were successful at four sites, and in 1990s resulted in major growth of the species’ population. Reintroduced at three sites near type locality in the Darling Range, S of Perth, at end of 1990s. Total population estimated at 1900–2000 individuals in 2001, by which year birds translocated in 1983 and 1985 to Mt Manypeaks, E of Two Peoples Bay, had produced a subpopulation four times the size of original Mt Gardner one. Population of Albany management area increased from 588 singing males in 1999 to 765 in 2001, in spite of fires during 2000. However, a series of lightning-induced fires during 2000–2004 severely affected Two Peoples Bay and Mt Maypeaks areas, reducing the number of singing males there to c. 278 in 2005 and 370 in 2006 External link . Total population now 950 mature individuals, split into two subpopulations occupying just 140 km² (1 Garnett, S. T., J. K. Szabo, and G. Dutson (2011). The Action Plan for Australian Birds 2010. CSIRO Publishing, Collingwood, Victoria, Australia. Close ). Currently distributed at five sites along almost 50 km of coast, mostly in protected areas, and including introduced population on Bald I; locally common within this tiny range. The decrease in population caused by recent wildfires, together with additional unexplained smaller-scale declines, a probable continuing reduction in habitat quality and number of mature individuals, a tiny range and the fact that this species is restricted to just five locations have led to it being uplisted to Endangered. However, without several decades of conservation interventions, particularly translocations, it would likely be Critically Endangered (2 Szabo, J.K., Butchart, S.H.M., Possingham, H.P. and Garnett, S.T. (2012). Adapting global biodiversity indicators to the national scale: a Red List Index for Australian birds. Biological Conservation. 148(1): 61–68. Close ).