Species

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.

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls.
Cramp, S.; Perrins, C. M. 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Taxonomic note
Ardea purpurea (Sibley and Monroe 1990, 1993) was split into A. purpurea and A. bournei by Hazevoet (1995). This treatment is not followed by the BirdLife Taxonomic Working Group although we do recognise consistent behavioural differences and that bournei is paler overall in colouration.

Population justification
The global population is estimated to number c.270,000-570,000 individuals (Wetlands International 2006), while national population estimates include: c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in China; < c.1,000 individuals on migration and < c.1,000 wintering individuals in Taiwan; < c.100 breeding pairs and c.50-1,000 individuals on migration in Japan and possibly < c.50 individuals on migration in Russia (Brazil 2009).

Trend justification
The overall population trend is decreasing, although some populations may be stable and others have unknown trends (Wetlands International 2006).

Ecology
Behaviour Populations breeding in the western Palearctic are migratory (del Hoyo et al. 1992) and travel on a broad front between breeding and wintering grounds (Kushlan and Hancock 2005). African and tropical-Asian populations are largely sedentary however, occasionally making local dispersive movements (del Hoyo et al. 1992). The species breeds from April to June in the western Palearctic, during the rains in Africa, and from June to October in the north of India or November to March in the south of India (del Hoyo et al. 1992). It is a colonial breeder (Hancock and Kushlan 1984, del Hoyo et al. 1992, Turner 2000, Kushlan and Hancock 2005) and although nesting group sizes are usually small (e.g. 2-3 pairs per colony in Africa) and rarely exceed 50 pairs (Turner 2000), colonies of up to 1,000 pairs have been recorded in some areas (Hancock and Kushlan 1984, del Hoyo et al. 1992). It often also nests on the periphery of colonies of other heron species such as Grey Heron Ardea cinerea (Kushlan and Hancock 2005). In migratory populations the autumn migration occurs from August to October (Hancock and Kushlan 1984), with the return passage in the spring beginning in March (Hancock and Kushlan 1984). On migration the species commonly occurs in small groups (the maximum recorded migratory groups sizes being 300-400 individuals) (del Hoyo et al. 1992) and throughout the year it will roost communally by day and by night (Hancock and Kushlan 1984) in groups of up to 100 individuals (Brown et al. 1982) although it generally feeds solitarily (Hancock and Kushlan 1984, del Hoyo et al. 1992). The species is mainly crepuscular, but may also feed diurnally (del Hoyo et al. 1992). Habitat The species inhabits wetlands from sea level to 1,800 m (Madagascar) (del Hoyo et al. 1992), showing a preference for dense, flooded, freshwater reedbeds (Phragmites spp.) in temperate areas (occupying Typha, Scirpus and Papyrus swamps elsewhere) (Kushlan and Hancock 2005). It also utilises lake shores, river margins (del Hoyo et al. 1992), ditches, canals, brackish water lagoons (Kushlan and Hancock 2005), rice-fields, mangroves and coastal mudflats (del Hoyo et al. 1992). Diet Its diet consists of fish 5-15 cm long (del Hoyo et al. 1992) (occasionally up to 55 cm), salamanders (Kushlan and Hancock 2005), frogs, insects (del Hoyo et al. 1992) (e.g. beetles, dragonflies, hemiptera (Kushlan and Hancock 2005) and locusts (Hancock and Kushlan 1984)), crustaceans (del Hoyo et al. 1992), spiders (Kushlan and Hancock 2005) and molluscs (Hancock and Kushlan 1984) as well as small birds and mammals, snakes and lizards (del Hoyo et al. 1992). Breeding site The nest is a platform of reeds stems or sticks (Kushlan and Hancock 2005) positioned over or beside water up to 3 m high in flooded reedbeds (del Hoyo et al. 1992), 3-4 m high in thickets or mangroves (Kushlan and Hancock 2005) or up to 25 m high in trees (del Hoyo et al. 1992). The species usually nests in loose single- or mixed-species colonies with Grey Heron Ardea cinerea, and although colony sizes are usually small, large groups of up to 1,000 pairs have been recorded (Hancock and Kushlan 1984, del Hoyo et al. 1992) (the colony size depends on the size of the area of marshland) (Kushlan and Hancock 2005). Management information Studies in southern France have shown that the overall conservation of this species in Europe is favoured by maintaining large uncut reedbeds with relatively high spring water levels (Barbraud et al. 2002).

Threats
The main threat to this species in Europe is the loss of reedbeds though direct elimination (to reduce sedimentation) (Kushlan and Hancock 2005), agricultural encroachment (Hockey et al. 2005), water management practices (Kushlan and Hancock 2005) (e.g. drainage) (Hockey et al. 2005) and reed cane harvesting (Kushlan and Hancock 2005).

Related state of the world's birds case studies

• Large dams threaten one of Africa's most important wetland ecosystems

References
Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, London.

Hancock, J.; Kushlan, J. 1984. The herons handbook. Croom Helm, London.

del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

Kushlan, J. A.; Hancock, J. A. 2005. The herons. Oxford University Press, Oxford, U.K.

Hockey, P. A. R.; Dean, W. R. J.; Ryan, P. G. 2005. Roberts birds of southern Africa. Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa.

Barbraud, C.; Lepley, M.; Mathevet, R.; Mauchamp, A. 2000. Reedbed selection and colony size of breeding purple herons Ardea purpurea in southern France. Ibis 144(2): 227-235.

Turner, D. 2000. Herons in Africa and the Malagasy Region. In: Kushlan, J. A.; Hafner, H. (ed.), Heron Conservation, pp. 99-122. Academic Press, San Diego.

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

Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.

Species factsheet from HeronConservation - The IUCN-SSC Heron Specialist Group

View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Butchart, S., Ekstrom, J., Malpas, L.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Ardea purpurea. Downloaded from http://www.birdlife.org on 19/06/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/06/2013.

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

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

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