Justification This species has an extremely 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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Family/Sub-family Threskiornithidae

Species name author (Linnaeus, 1766)

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Christidis and Boles (1994), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), SACC (2005 + updates), Sibley and Monroe (1990, 1993), Stotz et al. (1996), Turbott (1990)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

1,200,000 - 3,200,000

unset

19,400,000 km²

No

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Behaviour All populations of this species undergo post-breeding dispersal movements¹ and are considerably nomadic⁴. In addition northern breeding populations are fully migratory¹ and may travel on a broad front (e.g. across the Sahara)³. Northern and southern breeding populations breed during the local spring, whilst breeding elsewhere coincides with the rains¹. The species nests in mixed-species colonies, either in small groups (e.g. 5-100 pairs in Africa)³ or in large aggregations of thousands of pairs^1. Outside of the breeding season flocks of over 100 individuals may occur on migration (Africa)³, and during the winter or dry seasons the species usually forages in small flocks^{1, 2} of up to 30 indivduals³. It often roosts communally at night in large groups (sometimes thousands of individuals) with other species, occasionally in trees far from wetland feeding sites³. Habitat The species feeds in very shallow water² and nests in freshwater or brackish wetlands with tall dense stands of emergent vegetation (e.g. reeds or rushes) and low trees or bushes^{1, 5}. It shows a preference for marshes at the edges of lakes and rivers², as well as lagoons, flood-plains, wet meadows^{1, 5}, swamps¹, reservoirs², sewage ponds, rice-fields and irrigated cultivation^{1, 5}. It less often occurs in coastal locations such as estuaries, deltas, saltmarshes² and coastal lagoons¹. Roosting sites are often large trees that may be far from water^{1, 3}. Diet The diet of the species varies seasonally depending on what is available². It takes adult and larval insects (e.g. aquatic beetles, dragonflies, grasshoppers, crickets, flies and caddisflies), worms, leeches, molluscs (e.g. snails and mussels), crustaceans (e.g. crabs and crayfish) and occasionally fish, frogs, tadpoles, lizards, small snakes and nestling birds¹. Breeding site The nest is a platform of twigs and vegetation usually positioned less than 1 m above water (occasionally up to 7 m) in tall dense stands of emergent vegetation (e.g. reeds or rushes), low trees or bushes over water¹.

Threats The species is threatened by wetland habitat degradation and loss^{1, 4} through drainage^{2, 5} for irrigation and hydroelectric power production⁷, clearing, grazing, burning, increased salinity, groundwater extraction and invasion by exotic plants⁵. It is also threatened locally by hunting^{1, 4}, disturbance and pesticides¹, and is susceptible to avian influenza so may be threatened by future outbreaks of the virus⁶.

References 1. del Hoyo et al. (1992). 2. Hancock et al. (1992). 3. Brown et al. (1982). 4. Snow and Perrins (1998). 5. Marchant and Higgins (1990). 6. Melville and Shortridge (2006). 7. Balian et al. (2002).

Further web sources of information

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Text account compilers Stuart Butchart (BirdLife International), Jonathan Ekstrom (BirdLife International), Lucy Malpas (BirdLife International)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Plegadis falcinellus. Downloaded from http://www.birdlife.org on 10/2/2010

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

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