Thaumatibis gigantea


Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA AVES Ciconiiformes Threskiornithidae

Scientific Name: Thaumatibis gigantea
Species Authority: (Oustalet, 1877)
Common Name/s:
English Giant Ibis
Pseudibis gigantea

Assessment Information [top]

Red List Category & Criteria: Critically Endangered   A2cd+3cd+4cd; C2a(i)   ver 3.1
Year Assessed: 2008
Assessor/s BirdLife International
Evaluator/s: Butchart, S. & Mahood, S. (BirdLife International Red List Authority)
This ibis has an extremely small, declining population as a result of hunting, disturbance and lowland deforestation. It is likely to continue to decline owing to deforestation and human disturbance. It therefore qualifies as Critically Endangered.

Geographic Range [top]

Range Description: Pseudibis gigantea is confined to northern Cambodia, where it is probably still fairly widespread but extremely rare, with a few birds surviving in extreme southern Laos, and a recent record from Yok Don National Park, Vietnam1. Its historical range spanned southern Vietnam and south-east and peninsular Thailand, where it is now extinct. Available data suggests that it has a patchy distribution across Cambodia2. Some areas of high density exist (Preah Vihear Protected Forest and probably Siem Pang), whilst other areas appear to have relatively low density populations, which may be clustered in some cases (Kulen Promtep Wildlife Sanctuary, Seima Biodiversity Conservation Area and probably Phnom Prich Wildlife Sanctuary)2. Systematic surveys have yet to be done in the Mondulkiri Protected Forest and Lomphat Wildlife Sanctuary - the latter in particular may support higher densities2. Together, this data suggests a minimum estimate of 100 pairs (20-30 at each of the two high density sites, 5-10 at each of seven low density sites)2. Further surveys might be expected to confirm other localities in suitable habitat areas, particularly in Lomphat Wildlife Sanctuary, the O Te lowlands and adjacent deciduous dipterocarp forest2.

Cambodia; Lao People's Democratic Republic; Viet Nam
Regionally extinct:
Range Map:
(click map to view full version)

Population [top]

Population: T. Clements in litt. (2007) has compiled all recent records of this species and has commented "Together, this data suggests a minimum estimate of 100 pairs (20-30 at each of the two high density sites, 5-10 at each of seven low density sites)"

Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Singles, pairs or small parties occur in marshes, pools, wide rivers and seasonal water-meadows in open, predominantly deciduous, dipterocarp lowland forest, although it seems to be dependant on soft mud around seasonal pools (trapeang). Its diet comprises a variety of invertebrates, crustaceans, small amphibians and reptiles. It frequently feeds in soft mud, but also forages on dry substrates. It nests in trees, almost always more than 5 km from human habitation2. It appears to be largely resident, but apparently wanders widely in response to local disturbance and seasonal water-levels.

Systems: Freshwater

Threats [top]

Major Threat(s): It has declined as a result of hunting, wetland drainage for agriculture, and deforestation. It relies on seasonal pools, which in the past were created by the now much depleted mega-fauna. The species appears to be very sensitve to human disturbance, particularly during the dry season when birds are concentrated around available waterholes, and this is almost certainly the greatest threat, rendering much apparantly suitable habitat unusable. There are plans to clear large areas of lowland dry forests, including Western Siem Pang IBA where the species occurs, for teak plantations.

Conservation Actions [top]

Conservation Actions: Conservation actions underway:

It occurs at least seasonally in Xe Pian National Biodiversity Conservation Area (NBCA) and Dong Khanthung proposed NBCA, Laos, and Lomphat Wildlife Sanctuary, Cambodia. It is depicted on public-awareness material in Laos and Cambodia as part of an ongoing campaign to reduce hunting of large waterbirds.

Conservation actions proposed:

Conduct further surveys to locate and quantify remaining populations in Laos and Cambodia. Investigate its breeding requirements, demography and seasonal movements. Establish further protected areas encompassing large tracts of habitat found to support populations of the species, including strict protection of suitable permanent wetlands, especially in the dry season. Consolidate and promote further public-awareness initiatives to reduce hunting of large waterbirds and wetland disturbance. At key sites, designate some suitable pools as for use only by ibises.

Citation: BirdLife International 2008. Thaumatibis gigantea. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.1. <www.iucnredlist.org>. Downloaded on 30 May 2009.
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