Milky stork  (Mycteria cinerea)

Classified as Vulnerable (VU) on the IUCN Red List 2007 (1) and listed on Appendix I of CITES (3).

The milky stork is a very large bird named for its creamy-white plumage (4) (5). The black flight feathers on the wing provide a dramatic contrast to the bird’s pale colouring, as does the thick yellow bill and dark facial skin (4) (5). During the breeding season, the bill becomes brighter orange while the facial skin and legs turn a vivid red (5).

This Southeast Asian species is known historically from Cambodia, Thailand, Vietnam, Malaysia and Indonesia, with the vast majority concentrated in Indonesia. Now, just 100 birds are thought to remain in Malaysia and only 50 in Cambodia, while populations in Thailand and Vietnam are believed to be locally extinct (6).

A primarily coastal resident, favouring tidal mudflats for foraging, and bordering mangroves or freshwater/peat swamp forest for nesting (2). This species has also been recorded from saline pools, freshwater marshes, fishponds and rice-fields, up to 50 kilometres inland (2) (4).

These storks can often be observed feeding in aggregations with other wading birds, such as lesser adjutant (Leptoptilos javanicus) and egrets (Ardeidae) (7). The bulk of the diet at Sungai Burong, Malaysia, is apparently large mudskippers (Periophthalmus), although the species has also been recorded feeding on small fish, snakes and frogs (2) (7).

The milky stork breeds colonially, often in multi-species aggregations that may sometimes contain up to several hundred milky stork nests, although more commonly 10 to 20 (7). Breeding appears to peak during the dry season, in January and February in Cambodia and in July and August in Indonesia (2) (7). Dry-season breeding probably coincides with maximum fish stocks, following the rainy season (7). Nests are typically built between 6 and 12 metres up large trees (2), and are fairly bulky structures of sticks, lined with fresh leafy twigs (7). Clutches generally contain one to four eggs, which are thought to be incubated for 27 to 30 days. Young are able to leave the nest and fly poorly at six to seven weeks, and can fly well by eight weeks, but are still dependent on food from their parents (7). Both male and female take part in incubating the eggs and caring for and feeding the young until they are ready to leave the nest (8).

The milky stork has experienced rapid declines in the face of habitat destruction, hunting and trade (4). Throughout the species’ range, mangrove forests are being destroyed by logging operations and for conversion to agriculture, human settlements and development schemes, particularly large-scale fish farms and tidal rice cultivation (in Indonesia) (4) (7). Hunting of eggs, chicks and adults for food and trade poses a serious threat across the species’ range, while poisoning, persecution and disturbance may pose a significant threat, although this has yet to be quantified (4).

The milky stork occurs in a number of protected areas across its range. In Cambodia, books and posters depicting the species, produced and distributed by the Wildlife Protection Office, have been used in a public environmental awareness campaign aimed at reducing the exploitation and hunting of large waterbirds (4) (7). The milky stork’s listing on Appendix I of CITES since 1987 prohibits all international trade in the species, although does nothing to prevent domestic trade (3). However, the species is also legally protected in Malaysia and Indonesia (7). As the wild population of milky stork has declined, the captive population has grown, but re-introduction attempts have so far been unsuccessful (6).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the milky stork see:

• del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World – Ostrich to Ducks. Vol. 1. Lynx Edicions, Barcelona.
• BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.