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LC
Bush Thick-knee Burhinus grallarius

Justification

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.

Taxonomic source(s)
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Identification
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.

Distribution and population
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).


Population justification
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.

Trend justification

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.

Ecology
It is a resident of open forest and woodland, preferring a scattering of fallen timber and ground carpeted with dead leaves. The species feeds nocturnally on insects taken from the ground and is thought to forage primarily in open country, including paddocks and stubble in agricultural areas (D. Watson in litt. 2006, D. Harley in litt. 2007) (in urban coastal areas birds forage on ovals, mudflats and saltmarsh) (C. Price in litt. 2007). Pairs occupy stable territories and display long-term site fidelity (D. Harley in litt. 2007). During the non-breeding season, individuals may gather in small flocks (D. Harley in litt. 2007).

Threats
Its decline in its southern range has been attributed to predation by the introduced Red Fox Vulpes vulpes, habitat clearance for agriculture and urban development, habitat degradation by pastoralism, and removal of fallen timber from habitat remnants. Other threats include poisoning from pesticides or insecticides and in urban areas, road mortalities and predation by cats and domestic dogs (T. Holmes in litt. 2006, D. Harley in litt. 2007). Population monitoring in south-eastern South Australia suggests that poor nesting success and a lack of juvenile recruitment are significant factors limiting populations (D. Harley in litt. 2007). Nestling mortality, probably owing to predation, appears to be the main cause of nesting failure (D. Harley in litt. 2007). Hunting of the species is illegal.

Conservation Actions Underway
Fox control has been trialled in Victoria in an attempt to reduce predation of adults and chicks (D. Robinson and G. Johnson in litt. 2006, D. Harley in litt. 2007). A post-graduate study into the demography and ecology of the species in New South Wales and Victoria has been completed (E. Tack in litt. 2006). A number of conservation projects for the species have been implemented in south-eastern Australia, in Victoria (3), South Australia (2) and New South Wales (4) (D. Harley in litt. 2006, D. Harley in litt. 2007, C. Price in litt. 2007). Habitat requirements of the species in different areas are becoming better understood. Community involvement and support for projects are increasing, and the profile of the species has been raised in many areas (C. Price in litt. 2007). Molecular studies at the Australian Museum were underway and expected to be completed in 2007, with the aim of clarifying whether genetic differentiation is evident between populations in northern and southern Australia (D. Harley in litt. 2007, C. Price in litt. 2007).
Conservation Actions Proposed
Improve fox control. Improve understanding of threatening processes, particularly pertaining to juvenile recruitment (C. Price in litt. 2007). Increase the rate of juvenile recruitment (which may necessitate large-scale fox control) (D. Harley in litt. 2007). Develop standardised techniques for surveying distribution and monitoring abundance (D. Harley in litt. 2007). Develop agreement with landholders to maintain litter layer and fallen timber in remnant woodland. Determine the minimum area of woodland needed to maintain sub-populations and incorporate where necessary into land-clearing guidelines. Promote the iconic status of the species amongst regional farming communities (D. Harley in litt. 2007). Increase understanding about its habitat requirements (D. Harley in litt. 2007).

References
Garnett, S. T.; Crowley, G. M. 2000. The action plan for Australian birds 2000. Environment Australia, Canberra.

Garnett, S.T., Szabo, J.K. and Dutson, G. 2011. The Action Plan for Australian Birds 2010. CSIRO Publishing, Collingwood.

Marchant, S.; Higgins, P. J. 1993. Handbook of Australian, New Zealand and Antarctic birds, 2: raptors to lapwings. Oxford University Press, Melbourne.

Watkins, D. 1993. A national plan for shorebird conservation in Australia. Australasian Wader Studies Group, Royal Australasian Ornithologists Union and World Wide Fund for Nature, Canberra.

Further web sources of information
Australian Govt - Action Plan for Australian Birds 2000 - Recovery Outline

Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Bird, J., Butchart, S., Garnett, S., Symes, A., Taylor, J.

Contributors
Carter, A., Christidis, L., Ford, H., Garnett, S., Harley, D., Holmes, T., Price, C., Tack, E., Weston, M., Woinarski, J.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Burhinus grallarius. Downloaded from http://www.birdlife.org on 29/08/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 29/08/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Least Concern
Family Burhinidae (Thick-knees)
Species name author (Latham, 1801)
Population size 10000-15000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 2,570,000 km2
Country endemic? No
Links to further information
- Additional Information on this species