White-shouldered Ibis (Pseudibis davisoni)

White-shouldered Ibis

[order] CICONIIFORMES | [family] Threskiornithidae | [latin] Pseudibis davisoni | [authority] Hume, 1875 | [UK] White-shouldered Ibis | [FR] Ibis de Davison | [DE] Weissschulteribis | [ES] Ibis de Davison | [NL] Witschouderibis

Subspecies

Genus Species subspecies Region Range
Pseudibis davisoni OR s Indochina, Borneo

Genus

The bird genus Pseudibis consists of two South-East Asian species in the ibis subfamily, Threskiornithinae. The Giant Ibis is also sometimes placed in this genus, as it is on PoB. It is closely related to the genus Geronticus.

Physical charateristics

Large, dark ibis with distinctive pale collar, bluish-tinged at close range. Dark overall, blackish, naked head, dull red legs and whitish patch on inner forewing. Similar species Red-naped Ibis Thaumatibis papillosa has red patch on hind crown and nape and lacks white collar. Giant Ibis Thaumatibis gigantea is much larger with uniformly paler, dark-barred head, upper neck, wing-coverts and secondaries

Listen to the sound of White-shouldered Ibis

[audio:http://www.planetofbirds.com/MASTER/CICONIIFORMES/Threskiornithidae/sounds/White-shouldered Ibis.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 75 cm size max.: 85 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 2  
      eggs max.: 4  

Range

Oriental Region : South Indochina, Borneo. This species now occurs in northern and eastern Cambodia (at least 90% of the global population), extreme southern Laos and East Kalimantan, Indonesia

Habitat

Wetlands and grassland, such as pools, marshes, open grasslands or watercourses including wide rivers with sand and gravel bars were formerly important for the species, however at least in Indochina deciduous dipterocarp forest (which is usually inundated during the wet season) now appears to be of major importanc

Reproduction

White-shouldered ibis are canopy-nesting solitary breeders, raising 1-3 chicks in the tropical dry season. Nests are built in trees at a height of five to ten meter above ground, and two to four eggs per clutch is thought to be normal

Feeding habits

It has been observed feeding in soft substrates on the forest floor as well as at small waterbodies; also in sediment formations in river channels. Amphibians were the most common prey type consumed by White shouldered Ibis. Also important were molecrickets, which during the dry season occur in the mud at trapaengs. The other prey such as invertebrate, leeches, snails, and eels.

Video White-shouldered Ibis

httpv://www.youtube.com/watch?v=T7VzRPtXSSY

copyright: J. del Hoyo


Conservation

This species has an extremely small and fragmented population as a result of deforestation, drainage of wetlands, hunting, disturbance and potentially a number of unknown factors, and is projected to undergo an extremely rapid population decline over the next three generations (25 years). It therefore qualifies as Critically Endangered. If conservation efforts succeed in bringing the largest remaining populations, in north-eastern Cambodia and along the Mekong channel, under effective protection, the species may warrant downlisting.
It has declined as a result of habitat loss, through logging, widespread piecemeal clearance of lowland forest, conversion of wetlands for agriculture (most of the Mekong floodplain in southern Laos has been converted to rice-paddy) and agro-industrial and infrastructure development (such as the proposed dams on the River Srepok). Habitat loss has been compounded by hunting of adult birds, eggs and chicks for food, and disturbance, leading to the loss of secure feeding, roosting and nesting areas. The hunting pressure is exacerbated by the fact that their primary habitats appear to be also a focus of people: large rivers and grassland/field complexes with high densities of ungulates and domestic livestock, however hunting may now be less of a threat in Cambodia following education initiatives and the confiscation of weapons. The Indonesian population was estimated at 30-100 individuals (BirdLife International 2001) but has apparently declined. A nationwide coordinated count of the species in Cambodia in 2009 recorded at total of 310 individuals and is thought to be even larger (BirdLife International 2009). Based on this survey data, a minimum population of 330 individuals seems appropriate
White-shouldered Ibis status Critically Endangered

Migration

Available evidence gives no suggestion that the species undertakes major seasonal movements.

Distribution map

White-shouldered Ibis distribution range map

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