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 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 Ardeidae

Species name author (Linnaeus, 1766)

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

Taxonomic note Ixobrychus minutus (Sibley and Monroe 1990, 1993; Christidis and Boles 1994) was split into I. minutus and I. dubius by Christidis and Boles (2008) but this treatment is not followed by the BirdLife Taxonomic Working Group (BTWG) because the authors fail to adequately document their treatment and do not provide valid references to support the argument.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

76,000 - 610,000

unset

29,400,000 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 Palearctic populations of this species undergo extensive post-breeding dispersal movements in all directions and are also fully migratory, travelling southward on a broad front¹ between August and October and returning to the north from March to April². Other populations (e.g. in the tropics) are resident but may make partial migratory movements connected with fluctuations in water-level¹. In the western Palearctic and India the species breeds mainly between May and July, breeding from October to January in Australia, June to February in South Africa, or in relation to the rains in tropical Africa¹. It breeds singly or occasionally in small loose groups in favourable areas¹ (e.g. 2-3 nests were spaced 50 m apart at the same pond, Africa)³. When not breeding the species may be found singly, in pairs (Africa)³, in small flocks of 5-15 individuals⁵ (e.g. on migration)¹, or roosting in groups of 30 individuals (Africa)³. In most areas it is mainly a crepuscular feeder^{1, 2} although it may be diurnal in some regions (e.g. South Africa)². Habitat The species is most common in freshwater marshes with beds of bulrushes Typha spp., reeds Phragmites spp.⁴ or other dense aquatic vegetation, preferably also with deciduous bushes and trees¹ such as willow Salix spp. or alder Alnus spp.^{1, 2}. It may also occupy the margins of lakes, pools and reservoirs¹, wooded and marshy banks of streams and rivers², desert oases, peat bogs¹, wooded swamps, wet grasslands, rice-fields¹, rank vegetation around sewage ponds⁴, and in places mangroves, the margins of saline lagoons¹ and saltmarshes². Diet Its diet varies with region and season¹ but it is essentially insectivorous and takes aquatic adult and larval insects such as crickets, grasshoppers, caterpillars¹ and beetles². Other food items include spiders, molluscs, crustaceans¹ (e.g. shrimp and crayfish)², fish, frogs, tadpoles, small reptiles and birds¹. Breeding site The nest is constructed from reeds and twigs¹ and is normally placed near open pools in thick emergent vegetation² (such as beds of bulrushes Typha spp. or reeds Phragmites spp.)⁴ close to the surface of the water or up to 60 cm above it⁵. Alternatively nests may be placed in low bushes or trees (e.g. alder Alnus spp. or willow Salix spp.) up to 2 m above water^{1, 2}. Preferred nesting sites are usually 5-15 m out from the shore in water 20-30 cm deep⁵. The species usually nests singly but may nest in loose colonies in favourable habitats with neighbouring nests as close as 5 m apart (solitary nests are usually 30-100 m apart)². Nests are often reused in consecutive years².

Threats The species is threatened by habitat degradation and loss⁶ through direct destruction, pollution¹ and hydrological changes (e.g. in rivers)². The species also suffers mortality as a result of drought and desertification on African staging and wintering grounds (degrades wetland habitats needed by the species)⁶.

References 1. del Hoyo et al. (1992). 2. Kushlan and Hancock (2005). 3. Brown et al. (1982). 4. Hockey et al. (2005). 5. Snow and Perrins (1998). 6. Hafner and Kushlan (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 (2010) Species factsheet: Ixobrychus minutus. 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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