Esacus magnirostris 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Charadriiformes Burhinidae

Scientific Name: Esacus magnirostris (Vieillot, 1818)
Common Name(s):
English Beach Thick-knee, Beach Stone-curlew
Burhinus giganteus giganteus Sibley and Monroe (1990, 1993)
Esacus giganteus
Esacus magnirostris magnirostris Christidis and Boles (2008)
Esacus neglectus neglectus Christidis and Boles (1994)
Taxonomic Source(s): Christidis, L. and Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. CSIRO Publishing, Collingwood, Australia.
Taxonomic Notes: Esacus magnirostris (del Hoyo and Collar 2014) was previously listed as E. giganteus; the name magnirostris has priority.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Barré, N., Freeman, A., Chartendrault, V. & Baudat-Franceschi, J.
Facilitator/Compiler(s): Benstead, P., Garnett, S., Harding, M., Pilgrim, J., Symes, A., Taylor, J., North, A.
This species qualifies as Near Threatened because it has a small population. If the population is found to be in decline it might qualify for uplisting to a higher threat category.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Esacus magnirostris is widespread around coasts from the Andaman Islands, India, Mergui Archipelago, Myanmar, islands off peninsular Thailand, and Peninsular Malaysia through Indonesia, Brunei, the Philippines, Papua New Guinea, the Solomon Islands, Vanuatu, New Caledonia (to France) and Australia. Its population in Australia may number c.5,000 birds and is probably stable (Garnett and Crowley 2000). Its density in Australia may have decreased locally on islands and in areas of the mainland where there are high levels of human disturbance and coastal development, especially around inhabited islands of the Great Barrier Reef and Torres Strait, and the wet tropical coast (Freeman 2003). Despite this, between the 1920s and 1970s the eastern part of the species' range appears to have extended south into New South Wales (Garnett and Crowley 2000). It is very rare on and around Sumatra and Vanuatu, where it has not been seen for six years (N. Barre in litt. 2003). Despite observation effort on many islets of the southern lagoon (“Ilots du lagon sud” IBA) and outside (Loyalty islands, remote islands IBAs) of New Caledonia, it has only been seen in the north (Chartendrault in litt. 2007). Even if probably partly underestimated because of remaining unexplored areas, the New Caledonian population seems very small and may be a relic, even if there is no visible trend (Chartendrault in litt. 2007).

Countries occurrence:
Australia; Brunei Darussalam; India; Indonesia; Malaysia; Myanmar; New Caledonia; Papua New Guinea; Philippines; Singapore; Solomon Islands; Thailand; Timor-Leste; Vanuatu
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:29800000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The population is thought to number c.5,000 individuals in Australia, 1,000 individuals in the Melanesian islands (G. Dutson in litt. 2002), and 10-20 individuals in New Caledonia. This totals at least 6,000 individuals, roughly equivalent to 4,000 mature individuals.

Trend Justification:  The population is suspected to be in decline owing to human disturbance and predation by invasive mammals.
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:4000Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Pairs may be found on most beaches within its range; in Australia these include short stretches of muddy sand among mangroves, coralline sands on atolls and prime surf beaches (Garnett and Crowley 2000). Beaches associated with estuaries and mangroves are particularly favoured. In New Caledonia, it is breeding on coral islets inside the lagoon, mainly on dead coral beaches near fringing reef, on upper shaded areas (Chartendrault in litt. 2007).  Adults are sedentary, although the species has a tendency for wide-ranging vagrancy. It lays a single egg in a scrape in the sand at the landward edge of the beach, often using the same area repeatedly. It forages mainly in the intertidal zone on crustaceans and other invertebrates (Garnett and Crowley 2000).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):10.5
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): The species appears to be threatened by extensive human disturbance of beach habitats in many areas (Garnett and Crowley 2000). It is also thought to be sensitive to predation by introduced mammals. Much of the species' habitat in Australia, particularly on islands, is secure. This species occurs at low densities and occupies linear habitats, increasing the potential for local extinctions to become regional ones; however, its apparent range expansion southwards in eastern Australia suggests that such extinctions do not represent genetic barriers (Garnett and Crowley 2000).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
No targeted conservation actions are known for this species.

Conservation Actions Proposed
Maintain a register of inhabited beaches. Monitor population trends, especially where human disturbance is prevalent. If necessary, control the use of beaches by humans and their dogs, particularly during breeding. Determine the relationship between human disturbance and breeding success.

Citation: BirdLife International. 2016. Esacus magnirostris. The IUCN Red List of Threatened Species 2016: e.T22728621A94992570. . Downloaded on 23 June 2018.
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