Justification of Red List Category
This species has been downlisted to Least Concern, because the total population, and three of the four subpopulations, are now not thought to approach the thresholds for classification as Vulnerable based on small, declining population size. This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The current overall population trend is unknown, but it is likely to be fluctuating locally owing to the impacts of wildfires, hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations).
The combined total for the populations of each subspecies given in Garnett et al. (2011) is 13,500 mature individuals.
The population is likely to be fluctuating locally owing to the impacts of wildfires (Garnett et al. 2011), and may be decreasing overall.
Psophodes nigrogularis is found in four isolated sub-populations in south-west and southern Australia. Nominate nigrogularis is restricted to a small area east of Albany where the population is c.500 mature individuals and decreasing (Garnett et al. 2011). Subspecies oberon is found in scattered localities in southern Western Australia and numbers c.5,000 mature individuals, and is probably declining. Subspecies lashmari on Kangaroo Island has a stable population of c.2,000 mature individuals. The fourth, leucogaster, has a declining population of c.6,000 mature individuals, and is restricted to a small number of widely scattered localities in southern South Australia and north-western Victoria. Following a series of fires in the Two Peoples Bay-Manypeaks area between December 2000 and December 2004, the number of singing males detected in censuses dropped from over 400 in 2001 to about 200 in 2005 (A. Burbidge in litt. 2007). There was a further decrease in the number detected in 2006 (about 175) but, while it is clear that fire had a major impact, it is not clear how much of the variation between years is attributable to survey technique or other causes (A. Burbidge in litt. 2007). In Fitzgerald River National Park, oberon is subject to population fluctuations in response to wildfire (A. Burbidge in litt. 2007).
Overall, the various subspecies occupy mallee eucalyptus, heath, shrubland or acacia vegetation, often near coasts. They feed by foraging on the ground for invertebrates.
Past clearance of mallee and heath vegetation for agriculture has been responsible for the substantial contraction and fragmentation of the species's range. About half of the habitat on Kangaroo Island that was suitable for lashmari has been cleared for agriculture. Over half of the habitat used by oberon has also been cleared for this purpose. Fire is currently the major threat in most areas. Fires are likely to further fragment populations and may have led to local extinctions of nigrogularis. The population increase of nigrogularis at Two Peoples Bay has been attributed to the exclusion of fire from the area since 1970. In 2004-2005, a fire at Mt Manypeaks had a significant impact on the local population of nigrogularis (Danks and Comer 2006). It is not known at what stage post-fire habitat is suitable for the species, but the Manypeaks fire was patchy and left a mosaic of burn intensities that may benefit the species in the future. The species has the ability to recover from this fire, as there are established populations nearby, and the recovery of vegetation had already begun in the winter of 2005, aided by high rainfall (Danks and Comer 2006). Many of the relatively widespread populations of oberon are likely to become extinct over time as a result of random processes from which they can no longer recover because they cannot recolonise.
Conservation Actions Underway
Following a fire at Mt Manypeaks in 2004-2005, a monitoring project was started in March 2005, which aimed to complete base-line post fire surveys of the species (Danks and Comer 2006). The project also involved increased fox control, cat trapping and improvements to fire management capabilities. Most of the remaining habitat on Kangaroo Island is protected. The population of nigrogularis has been surveyed, and all sub-populations are actively protected from fire, particularly those at Two People's Bay. The recovery of this subspecies is being managed by the South Coast Threatened Birds Recovery Team. Samples for analysis of the genetic relationship of the subspecies were being collected in 2007 and it was anticipated that analysis would occur in 2007-2008 (A. Burbidge in litt. 2007).
Text account compilers
Benstead, P., Garnett, S., McClellan, R., Symes, A., Taylor, J.
BirdLife International (2019) Species factsheet: Psophodes nigrogularis. Downloaded from http://www.birdlife.org on 22/05/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/05/2019.