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). The population trend appears to be fluctuating, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very 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 Laridae

Species name author (Pallas, 1811)

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Christidis and Boles (1994), Christidis and Boles (2008), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), Sibley and Monroe (1990, 1993), Turbott (1990)

Synonyms Chlidonias hybridus Dowsett and Forbes-Watson (1993), Chlidonias hybridus Cramp and Simmons (1977-1994), Chlidonias hybridus Sibley and Monroe (1990, 1993)

Taxonomic note Gender agreement of species name follows David and Gosselin (2002a).

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

300,000 - 1,500,000

unset

10,000,000 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 Northern breeding populations of this species are fully migratory whilst tropical breeders are more nomadic or locally dispersive¹. The species breeds from May to early-June² in monospecific colonies of 10-100 pairs¹. After breeding it departs for the wintering grounds from late-July to September, returning again between April and May². The species sometimes forages singly, but is more common in small groups or larger mixed-species flocks on passage and in the winter³. Habitat The species utilises a variety of wetland habitats but shows a preference for freshwater marshlands with scattered pools, particularly where the surrounding vegetation is grazed by cattle or horses². It frequents inland lakes, rivers, marshes, temporary pans (e.g. in Africa), artificial fish-ponds and drainage-ponds covered with water-lilies (e.g. in Italy)¹, swamps, river pools, reservoirs, large dams, sewage-ponds, flooded saltmarshes, arable fields (e.g. in Australia)^{1, 4} and rice-fields¹. In Australia the species also occurs along the coast on estuaries, coastal lagoons, creeks in mangrove swamps³ and tidal mudflats¹. Diet Its diet consists of terrestrial and aquatic insects¹ (e.g. Dytiscidae, adult and larval Odonata, Orthoptera, flying ants¹ and mosquitoes²), spiders, frogs, tadpoles, small crabs¹, shrimps² and small fish¹. Breeding site The nest is a heap of aquatic vegetation^{1, 2} or dry grass¹, placed either on floating and emergent vegetation over water 60-80 cm deep or resting on the bottom of very shallow water¹. The species nests in colonies, neighbouring pairs spaced between 1 and 5 m apart¹, and may forage up to 9 km away from breeding sites (more usually within 1 km)¹.

Threats The species suffers nest destruction from the invasive rodent species Myocastor coypus in Italy⁵. Utilisation Large numbers of eggs are collected for sale and local consumption in India (this may be causing population declines in some areas)¹, and fishermen collect eggs in Ukraine¹.

References 1. del Hoyo et al. (1996). 2. Richards (1990). 3. Snow and Perrins (1998). 4. Higgins and Davies (1996). 5. Arduin (1997).

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 (2010) Species factsheet: Chlidonias hybrida. Downloaded from http://www.birdlife.org on 6/9/2010

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.

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