Giant Ibis and White-shouldered Ibis
White-shouldered Ibis Pseudibis davisoni and Giant Ibis Thaumatibis gigantea are large wading birds now found almost exclusively in the forests of Cambodia. Both are Critically Endangered, and are ‘flagship species’ in Cambodia; Giant Ibis is the country’s national bird. Their successful conservation will set a significant precedent for the protection of the other forest species there facing similar threats.
The key site for conservation of these species is Western Siem Pang: one of the last remnants of a huge forest ecosystem that once covered most of central Indochina, and a BirdLife Forest of Hope. The forests here are still extensive and, within them, BirdLife has identified a key site covering around 150,000 ha, with 90% intact forest and populations of no fewer than five Critically Endangered bird species: the two ibises, and three species of vulture.
The Giant Ibis has an extremely small population, which has undergone rapid decline as a result of forest loss, driven primarily by clearing of land in order to develop industrial scale agriculture, small scale agricultural encroachment and infrastructure developments. It is now extinct in Vietnam and Thailand, and nearly so in Laos. Its survival depends on its conservation in Cambodia.
Singles, pairs or small parties occur in open deciduous dipterocarp forests, often observed feeding at forest pools (trapeangs) and grasslands (veals). The species’s diet comprises a variety of invertebrates, crustaceans, eels, small fish and amphibians, which it often searches for in the soft mud around or in deeper water within trapaengs. Nests are in large trees during the wet season, generally more than 4 km from human habitation.
The White-shouldered Ibis also has a very small and fragmented declining population as a result of habitat loss, hunting and disturbance; again, Cambodia holds the key to its survival.
Deciduous dipterocarp forest with wetlands and grassland, such as pools, marshes, open grasslands or watercourses are typical habitat. In contrast to Giant Ibis, the White-shouldered Ibis breeds during the dry season and roosts communally during the wet season. As for Giant Ibis, trapaengs are particularly favoured foraging habitats. The diet is mainly amphibians, invertebrates and occasionally eels, all found in trapaengs. The species is often associated with large ungulates, which may help to create and maintain seasonal pools. Large wild ungulates have now all but disappeared from the region, so the White-shouldered Ibis may now be more closely associated with domestic water buffalo and cattle, which have replaced this ecological role once played by wild ungulates.
Actions being implemented
- Establishing new Protected Forests covering core deciduous dipterocarp habitats of the species
- Supporting effective protected area management including law enforcement and sustainable development initiatives to enhance the economic value of conservation for local communities
- Increased communal roost site protection and roost site creation within Protected Forest habitat in Western Siem Pang.
- Establishment of the Cambodian Ibis working group to coordinate conservation activities at priority sites.
- Determining and regularly monitoring the Giant Ibis and White‐shouldered Ibis population size and trend
- Improving understanding of the causes of nest failure and promoting measures to increase nesting success in both species
- Improving understanding of Giant Ibis and White-shouldered Ibis ecology and promoting habitat management that benefits these species
- Promoting the conservation of Western Siem Pang Forest and other sites that support Giant Ibis and White-shouldered Ibis
Results are presented in (and used to update) the species factsheets in the BirdLife/IUCN Red List of Birds annually.