Threatened Species of the Northern Territory

ASIAN DOWITCHER Limnodromus semipalmatus

Description

The Asian Dowitcher is a large shorebird with long dark legs and a long straight dark bill that is slightly ‘swollen’ at the tip. In non-breeding plumage (typical of Australian visitors) it has a streaked brown forehead, crown and nape, a dark line from the base of the bill through the eye and a broad white ‘eye-brow’. The upperparts are mottled grayish-brown and the underparts are white with fine darker streaking on the flanks and fine dark barring on the tail and rump. Distribution The Asian Dowitcher breeds in Siberia (Russia) and Mongolia (China). The majority of the global population overwinters on the coasts of Asia, especially Indonesia, and a small number reaches Australia each year, typically between September and April. Most of the visiting Australian population remains in the north-west, but smaller numbers have been reported from coastal areas across northern Australia and down the east.

In the Northern Territory (NT) they have been reported in small numbers in the Darwin region, central coastal Arnhem Land, Blue Mud Bay and the Port McArthur region. They probably occur

Known locations of the Asian Dowitcher at a number of other locations on the NT coast, but never in large numbers. The largest single count was of 70 birds at Port McArthur (Chatto 2003). Conservation reserves where reported: Casuarina Coastal Reserve.

For more information visit nt.gov.au/environment/animals/threatened-animals/birds

Conservation statusAustralia: Not listedNorthern Territory: Vulnerable

Ecology

After the breeding in the northern summer in Siberia and Mongolia, Asian Dowitchers migrate southwards to overwinter in Asia and Australia. During this non-breeding season (the austral summer), birds in the NT are generally solitary or in small flocks and seek out sheltered coasts.They feed on intertidal mudflats on polychaetes, molluscs and insect larvae, often in the soft mud near the sea-edge. During high tides they often roost among flocks of other wader species (Geering et al. 2007). Conservation assessment

The global population size is relatively small (c. 23,000; Birdlife International 2010) and small numbers migrate to Australia. The NT, especially around the Top End coastline, provides important non-breeding and stop-over sites. The status of this species globally and in Australia was reviewed in 2010 (by BirdLife International (2011) and Garnett et al. (2011), respectively). BirdLife International (2011) classifies the species globally as Near Threatened C1, and Garnett et al. (2011) considers it Near Threatened A3c+4c,C2a(ii),D1 in Australia. The Australian population does not exceed 1 000 birds and the NT population is much smaller than this. Since the species is considered in decline globally, IUCN regional assessment guidelines recommend no downgrading of regional threatened species status. This species qualifies as Vulnerable in the NT (under criterion D1), based on: A small migratory population reaching Australia (<1 000); and Global decline due to habitat loss and destruction in northern hemisphere breeding grounds.

Threatening processes

Declines are largely due to draining of wetlands leading to loss of habitat on the breeding grounds, and pollution, habitat loss and human disturbance at Asian overwintering and staging grounds. The non-breeding grounds of the species in northern Australia are considered generally free of such disturbances (Garnett et al. 2011). Conservation objectives and management

In the NT, the primary conservation objective is to maintain stable non-breeding populations by retaining healthy intertidal mudflat habitats. Improved knowledge of the numbers, distribution and movements of shorebirds along our coastline is also needed. Secondarily, the Australian Government should be supported in its international endeavours to promote conservation of shorebirds along the East Asian-Australasian flyway.

Compiled by

Simon Ward [updated December 2012] References Birdlife International (2011). Species factsheet: Limnodromus semipalmatus. Downloaded from http://www.birdlife.org on 04/10/2011.

Chatto, R. (2003). The distribution and status of shorebirds around the coast and coastal wetlands of the Northern Territory. (Technical Report 73, Parks and Wildlife Commission of the Northern Territory, Darwin.) http://www.nt.gov.au/nreta/publications/wildlife/science/pdf/2003_shorebirds_rpt76.pdf

Garnett, S.T., Szabo, J.K., and Dutson, G. (2011). The action plan for Australian Birds 2010. (CSIRO Publishing/Birds Australia, Melbourne.)

Geering

, A., Agnew, L. and Harding, S. (2007). Shorebirds of Australia. (CSIRO Publishing, Melbourne.

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, A., Agnew, L. and Harding, S. (2007). Shorebirds of Australia. (CSIRO Publishing, Melbourne.)

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