|Scientific Name:||Mesophoyx intermedia|
|Species Authority:||(Wagler, 1829)|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
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.
Native:Angola (Angola); Australia; Bangladesh; Benin; Bhutan; Botswana; Brunei Darussalam; Burkina Faso; Burundi; Cambodia; Cameroon; Cape Verde; Central African Republic; Chad; China; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Eritrea; Ethiopia; Gabon; Gambia; Ghana; Guam; Guinea; Guinea-Bissau; India; Indonesia; Japan; Kenya; Korea, Democratic People's Republic of; Korea, Republic of; Lao People's Democratic Republic; Lesotho; Liberia; Malawi; Malaysia; Mali; Mauritania; Micronesia, Federated States of; Mozambique; Myanmar; Namibia; Nepal; Niger; Nigeria; Northern Mariana Islands; Oman; Pakistan; Palau; Papua New Guinea; Philippines; Russian Federation; Rwanda; Senegal; Sierra Leone; Singapore; Somalia; South Africa; South Sudan; Sri Lanka; Sudan; Swaziland; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Uganda; Viet Nam; Zambia; Zimbabwe
Vagrant:Christmas Island; Jordan; Maldives; New Zealand; Seychelles; United Arab Emirates; United States; Yemen
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The global population is estimated to number c.180,000-1,300,000 individuals (Wetlands International 2006), while national population estimates include: c.10,000-100,000 breeding pairs, c.1,000-10,000 individuals on migration and c.1,000-10,000 wintering individuals in China; < c.100 breeding pairs and c.1,000-10,000 wintering individuals in Taiwan; c.100-10,000 breeding pairs, c.50-1,000 individuals on migration and < c.50 wintering individuals in Korea and c.10,000-100,000 breeding pairs, c.1,000-10,000 individuals on migration and < c.50 wintering individuals in Japan (Brazil 2009).|
|Habitat and Ecology:||Behaviour North-Asian populations of this species are fully migratory, leaving Japan in September-October to winter in the Philippines and Borneo (Kushlan and Hancock 2005), and returning to breeding colonies in April (del hoyo et al. 1992). The majority is predominantly sedentary however, with some populations making limited nomadic or partially migratory movements (Brown et al. 1982) in response to changing water levels (Hockey et al. 2005). The breeding season varies regionally (del hoyo et al. 1992), but is usually centered around the wet season (Kushlan and Hancock 2005), with birds breeding in mixed-species colonies (del hoyo et al. 1992) of between 7, 20 (Hockey et al. 2005) and hundreds of pairs (sometimes up to thousands) (Marchant and Higgins 1990). The species is diurnal (del hoyo et al. 1992, Kushlan and Hancock 2005) and usually feeds singly, but old records suggest (Kushlan and Hancock 2005) that it may form flocks of 15-20 individuals (sometimes up to 250) (Brown et al. 1982, del hoyo et al. 1992), occasionally forming concentrations around permanent water during droughts (Kushlan and Hancock 2005). During the night the species roosts communally in trees over water (del hoyo et al. 1992, Hockey et al. 2005) in groups of 20 or more (Marchant and Higgins 1990). Habitat The species inhabits lowlands from sea-level to 1,000 m in Sumatra, and 1,450 m in Nepal (del hoyo et al. 1992). It shows a preference for sheltered flood-plains and seasonal wetlands with water less than 80 mm deep and emergent grasses, herbs, sedges, reeds or rushes and abundant aquatic vegetation (Marchant and Higgins 1990) (generally avoiding areas where vegetation is too thick for feeding) (Kushlan and Hancock 2005). Such habitats include seasonally flooded marshes, inland deltas (e.g. Okavango Basin, Botswana) (Hockey et al. 2005), ponds, swamp forest (Kushlan and Hancock 2005), freshwater swamps, pools, rivers, streams, rice-fields, the margins of freshwater, brackish and saltwater lakes (Brown et al. 1982, del hoyo et al. 1992, Kushlan and Hancock 2005), wet meadows, and flooded and dry pasture near water (Brown et al. 1982, del hoyo et al. 1992, Hockey et al. 2005, Kushlan and Hancock 2005). It occurs less often in coastal habitats, but may roost in mangrove swamps (Hancock and Kushlan 1984, del hoyo et al. 1992), and frequents mudflats, tidal estuaries (del hoyo et al. 1992), coastal lagoons (Brown et al. 1982), saltmarshes, and tidal streams and rivers (Marchant and Higgins 1990, Kushlan and Hancock 2005). Diet In aquatic habitats the diet of this species consists predominantly of fish less than 10 cm long (del hoyo et al. 1992, Hockey et al. 2005) (including eels, perch Macquaria, gudgeon and mosquitofish Gambusia) (Kushlan and Hancock 2005), as well as frogs, crustaceans (e.g. crayfish) (del hoyo et al. 1992, Hockey et al. 2005, Kushlan and Hancock 2005) and aquatic insects (e.g. leeches, water bugs and dragonfly larvae) (del hoyo et al. 1992, Hockey et al. 2005, Kushlan and Hancock 2005). It will also take terrestrial prey in drier habitats (Kushlan and Hancock 2005) including grasshoppers (del hoyo et al. 1992, Hockey et al. 2005), mole crickets, bugs and beetles, snakes (Kushlan and Hancock 2005), spiders (del hoyo et al. 1992, Hockey et al. 2005, Kushlan and Hancock 2005) lizards (del hoyo et al. 1992, Kushlan and Hancock 2005), and exceptionally birds (del hoyo et al. 1992). Breeding site The species breeds colonially with other species (del hoyo et al. 1992) but does not concentrate into dense groups; individual nests being typically situated 0.5 m away from each other (Marchant and Higgins 1990). The nest is a shallow platform of sticks and other marshland vegetation (Brown et al. 1982, Hockey et al. 2005, Kushlan and Hancock 2005) usually positioned in trees standing in water or over reedbeds (Brown et al. 1982, Marchant and Higgins 1990) (e.g. in inland swamps or mangroves) (Kushlan and Hancock 2005), at heights of 3-6 m and occasionally up to 20 m (del hoyo et al. 1992). The species may also nest on ledges, in reedbeds or in bushes (Brown et al. 1982).|
|Systems:||Terrestrial; Freshwater; Marine|
|Major Threat(s):||This species has declined markedly in Japan since the 1960s due to pollution and the disturbance of nesting colonies (Hancock and Kushlan 1984, del hoyo et al. 1992). The species is also threatened in the Northern Territory of Australia by the degradation of flood-plain habitats owing to grazing, burning, invasion by introduced plants (Marchant and Higgins 1990) (particularly Mimosa pigra and Salvinia molesta (Maddock 2000)), reduced water flows from drainage and water diversion for irrigation (Marchant and Higgins 1990, McKilligan 2005), levee breaking by feral buffalo (Marchant and Higgins 1990, Maddock 2000) (allowing salt intrusion and accumulation of tidal sediment (Marchant and Higgins 1990)), clearing of swamp forest, and pollution from mineral extraction (Maddock 2000). Utilisation This species is hunted and traded at traditional medicine markets in Nigeria (Nikolaus 2001).|
Brazil, M. 2009. Birds of East Asia: eastern China, Taiwan, Korea, Japan, eastern Russia. Christopher Helm, London.
Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, London.
Delany, S.; Scott, D. 2006. Waterbird population estimates. Wetlands International, Wageningen, The Netherlands.
del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.
Hancock, J.; Kushlan, J. 1984. The herons handbook. Croom Helm, London.
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.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: http://www.iucnredlist.org. (Accessed: 19 June 2012).
Kushlan, J. A.; Hancock, J. A. 2005. The herons. Oxford University Press, Oxford, U.K.
Maddock, M. 2000. Herons in Australia and Oceania. In: Kushlan, J. A.; Hafner, H. (ed.), Heron conservation, pp. 123-149. Academic Press, San Diego.
Marchant, S.; Higgins, P. J. 1990. Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Oxford University Press, Melbourne.
McKilligan, N. 2005. CSIRO, Collingwood, Australia.
Nikolaus, G. 2001. Bird exploitation for traditional medicine in Nigeria. Malimbus 23: 45-55.
|Citation:||BirdLife International 2012. Mesophoyx intermedia. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.|
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