||Burhinus grallarius (Latham, 1801)
||Bush Thick-knee, Bush Stone-curlew
||Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
||54-59cm. A slim, long-legged and long-tailed thick-knee. Has a grey and rufous morph. Cryptic plumage typical of the genus. Has long wings with rather broad, square, fingered tips. Large pale eyes in its big round head with a relatively fine dark bill. Similar spp. Generally unmistakeable but could be confused with beach thick-knee Esacus magnirostris which has a much larger bill and strictly inhabits coastal areas. Could also be confused with nightjars Caprimulgus but these have a very different flight pattern and are considerably smaller in size. Voice Nocturnal wailing call.
|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Carter, A., Christidis, L., Ford, H., Garnett, S., Harley, D., Holmes, T., Price, C., Tack, E., Weston, M.A. & Woinarski, J.
||Benstead, P., Bird, J., Butchart, S., Garnett, S., Symes, A., Taylor, J.
This widespread species declined historically in the southern parts of its range, primarily owing to the destruction and degradation of its preferred woodland habitat, predation by introduced foxes and interactions with habitat loss, however most of these declines occurred prior to the past three generations (32 years). The species remains common in northern Australia, including in urban areas where there is no evidence of declines despite depredation from feral and domestic cats and dogs. As there is no evidence to suggest the species has undergone a moderately rapid population decline over three generations, and the species’s range and population are both large and do not approach any of the thresholds for classification as Vulnerable, it has therefore been downlisted to Least Concern.
|Previously published Red List assessments:|
- 2012 – Least Concern (LC)
- 2008 – Near Threatened (NT)
- 2007 – Near Threatened (NT)
- 2004 – Near Threatened (NT)
- 2000 – Lower Risk/near threatened (LR/nt)
- 1994 – Lower Risk/least concern (LR/lc)
- 1988 – Lower Risk/least concern (LR/lc)
|Range Description:||Burhinus grallarius has been recorded from all but the most arid parts of mainland Australia, and many offshore islands. A tiny breeding population is also found in southern New Guinea (Papua, formerly Irian Jaya, Indonesia, and Papua New Guinea). In Australia, it is now largely absent south and east of the Great Dividing Range, and is scarce elsewhere in southern Australia. Historic declines led to its disappearance from 90% of its mainland range in South Australia (D. Harley in litt. 2006), however it remains common in northern Australia and on many continental islands, even within towns (S. Garnett in litt. 2006, 2011), although it has declined in southern Queensland. The total Australian population has been estimated at 15,000 individuals (Watkins 1993), and in 2010 the total population was estimated to almost certainly exceed 10,000 mature individuals (S. Garnett. in litt. 2011).|
Australia; Indonesia; Papua New Guinea
|♦ Continuing decline in area of occupancy (AOO):||Yes|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||9350000|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Continuing decline in number of locations:||Yes|
|♦ Extreme fluctuations in the number of locations:||No|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total Australian population has separately been estimated at 15,000 individuals, and to "almost certainly exceed 10,000 mature individuals" (Garnett et al. 2011). The population is therefore placed in the band 10,000-15,000 mature individuals.|
This widespread species declined historically in the southern parts of its range, primarily owing to the destruction and degradation of its preferred woodland habitat, predation by introduced foxes and interactions with habitat loss, however most of these declines occurred prior to the past three generations (32 years). The species remains common in northern Australia, including in urban areas where there is no evidence of declines despite depredation from feral and domestic cats and dogs. It is therefore suspected to have undergone a slow overall population decline during the past three generations.
|Current Population Trend:||Decreasing|
|♦ Number of mature individuals:||10000-15000||♦ Continuing decline of mature individuals:||Yes|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ No. of subpopulations:||1||♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||Yes|
|♦ No. of individuals in largest subpopulation:||100|