The noisy scrub-bird is a small, solidly built bird measuring 22-26 cm in length. The species has a triangular head profile, strong pointed bill, powerful legs, long graduated tail and short rounded wings. Adults are brown above with rufous wings and faint dark cross barring extending from the head to the tip of the tail. The dark bars are very fine on the head, broader and more obvious on the back and form irregular bands on the tail feathers. The underparts are paler with a buff coloured abdomen grading to bright rufous around the vent. Atrichornis clamosus (noisy scrub-bird) Conservation Advice Page 2 of 12 The species is sexually dimorphic in size and plumage. During the breeding season, females have a mean weight of 34 g while males have a mean weight of 51 g. Adult males have a dark grey band of variable width across the off-white throat and prominent white side flashes. Females have cream coloured throats. Juveniles lack barring and have buff foreneck and breast.
Noisy Scrub-bird |
Status: Endangered on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Atrichornis clamosus
Climate change is an emerging threat due to increased temperature; reduced rainfall and increased storm intensity which are likely to increase the threat of fire (CSIRO BoM 2017 DPaW 2014).
Over time; the threat from bushfires is likely to increase for noisy scrub birds; as fire intensity and frequency are predicted to increase in their primary habitat as a result of climate change (Bradstock 2010 Garnett et al. 2013).
Threats The primary threat to the noisy scrub bird is increasing fire frequency and intensity (Garnett et al. 2011 DPaW 2014); which is likely to be compounded by increased predation; including by cats and foxes; following intense fire events.
Threat factor Threat Evidence base type and status Fire Increased fire known Noisy scrub birds require long unburnt habitat to breed (DPaW frequency present 2014).
Fire is known to lead to increased predation for cover dependent species.
It is inferred from studies on eastern bristlebird that cover dependent birds; such as noisy scrub birds; are likely to be highly susceptible to predation after fire due to loss of dense protective cover and a greater number of individuals in small refuge areas to which feral predators have increased access (Lindenmayer et al. 2009 OEH 2012).
These potential impacts derive from issues including seasonality of burning (i.e. during breeding); removal of key forage support (i.e. seeding species) and the increase in total fire frequency.
The Committee considers that the noisy scrub bird is eligible for listing as Endangered under Criterion 1 (A4a; c) as the population is likely to undergo a severe reduction over three generations (18 years); based on a decline of more than 50 percent since 2001; and a likelihood of further population decline in the future due to significant habitat losses and ongoing threatening processes; particularly increased fire frequency and intensity.
Fire is considered the primary threat to the species; and a large fire has the capacity to burn several sites in a single event.
While the range of the noisy scrub bird has increased since it was re discovered in 1961 through natural dispersal and targeted translocations; significant areas within this newly expanded range have been considerably impacted through large fire events; particularly between 2001 and and more recently in 2015 and 2016 (Comer Burbidge 2016).
Invasive species o Implement a predator control program to reduce the number of cats and foxes at all known noisy scrub bird sites; especially immediately after fire events (planned or unplanned). o Undertake a control program for weeds and introduced herbivores where they are observed to threaten; or pose a threat to; the noisy scrub bird.