Black Ibis

An ibiz skoazioù gwenn^{(Daveoù a vank)} a zo ur spesad evned, Pseudibis davisoni an anv skiantel anezhañ.

Anvet e voe Geronticus Davisoni (kentanv) da gentañ-penn (e 1875) gant ar skiantour breizhveuriat Allan Octavian Hume (1829-1912) da zougen bri d'an evnoniour breizhveuriat William Ruxton Davison (?-1893).

Doareoù pennañ

Boued

Annez

Kavout a reer ar spesad e kreisteiz Indez-Sina hag e Borneo^[1] ma plij dezhañ bevañ nepell diouzh al lec'hioù dour (geunioù, gwernioù, lennoù, stêrioù).

Liammoù diavaez

• (en) Pseudibis davisoni el lec'hienn BirdLife International.
• (en) Pseudibis davisoni e lec'hienn an International Union for Conservation of Nature (IUCN).
• (en) Pseudibis davisoni el lec'hienn Avibase.

Notennoù ha daveennoù

L'ibis de clatell blau (Pseudibis davisoni) és un ocell de la família dels tresquiornítids (Threskiornithidae). El nom comú en algunes llengües, com ara en francès, ibis de Davison,i també el nom específic, és un homenatge a l'ornitòleg britànic William Ruxton Davison.

Morfologia

• Fa 75-85 cm de llarg.
• Plomatge fosc, amb un collaret distintiu clar que a curta distància apareix blavós. Taca blanquinosa al bordell anterior de les ales.
• Cap sense plomes, amb la pell negra.
• Potes vermelles.

Hàbitat i distribució

Habita llacs, rius, aiguamolls i terres de conreu del Sud-est asiàtic. Actualment només es pot trobar, i en petit nombre, al nord de Cambotja i zona limítrofa de Laos, sud de Vietnam i zona central de Borneo.

Referències

The white-shouldered ibis (Pseudibis davisoni) is a large species of bird in the family Threskiornithidae. It is native to small regions of Southeast Asia, and is considered to be one of the most threatened bird species on this part of the continent.^[2]

Taxonomy and systematics

The white-shouldered ibis was first described by Hume (1875), who originally named the species Geronticus davisoni after his bird collector William Ruxton Davison.^[3] Based on this species’ observed similarity with the black ibis (Elliot, 1877), the two species were placed in the same genus.^[3] In the more recent past, this ibis has often been classified as a subspecies of the black ibis;^[4][5][6] but is currently recognised as a separate species.^[2]

Description

The adult stands 60–85 cm tall,^[7][8] with males being slightly larger and having slightly longer bills than females.^[9][6] Its only available biometrics are measurements from a single unsexed specimen originating from the 19th century,^[5] which include a wing length of 419mm, culmen length of 197mm, tarsus length of 83mm and tail length of 229mm.^[10] The plumage is brownish-black, with glossy blue-black wings and tail, and a bare slate-black head^[7][8] which has also been reported as blue^[11][12] or white.^[3] A conspicuous neck collar comprising a bluish-white band of bare skin which is broader at the back and narrower at the front extends from the chin around to the nape at the base of the skull.^[7][8][6] The pale blue is most easily detectable at close range,^[2] although this collar may sometimes be completely white.^[3] The legs are dull red, the iris is orange-red, and the large de-curved bill is yellowish-grey.^[7]

The white-shouldered ibis owes its name to the clear white patch visible on the upper part of the neck and chin in some individuals. These white patches may appear as “white shoulders” in flight.^[13] In flight, it is also identified by its conspicuous white wing patch, which is visible only as a thin white line when the wings are closed.^[3] The white-shouldered ibis is morphologically similar to its Indian congener the black or red-naped ibis Pseudibis papillosa, but lacks the red tubercles on the nape;^[4] and is slightly larger, more robust and has a longer neck and legs.^[3] The tail also appears shorter and spreads downwards, not straight as in the black ibis.^[3]

The juvenile has dull-brown plumage with a tuft of brown feathers on the bluish-white nape, a grey-brown iris, pale yellow legs and dull white feet.^[6][7]

Vocalizations generally consist of loud, mournful calls that have been described as “weird and unearthly screams”.^[7] The hoarse calls of territorial individuals have been described as “errrrh” or “errrrrroh”.^[7][6] It also utters honking screams of “errrrh owk owk owk owk owk” and more subdued “ohhaaa ohhaaa” and “errrrrah”.^[7][6] It makes a loud, harsh “klioh klioh” call during copulation, resembling that of the black woodpecker.^[6]

Distribution and habitat

This southeast Asian ibis was once much more widespread than presently. It used to extend throughout Southeast Asia from Myanmar to Thailand, Malaysia, Cambodia, Laos, Vietnam and north into Yuman in China.^[5] The current population is very small and its distribution highly fragmented, being restricted to northern and eastern Cambodia, southern Vietnam, extreme southern Laos and East Kalimantan.^[12]

Cambodia, the species' largest stronghold, holds an estimated 85-95% of the global population.^[14][15] The largest known Cambodian white-shouldered ibis subpopulation resides in Western Siem Pang Important Bird Area (minimally 346 individuals).^[16] Other sites in Cambodia that hold considerable numbers of white-shouldered ibis include Kulen Promtep Wildlife Sanctuary, Lomphat Wildlife Sanctuary and the central section of the Mekong River.^[17] It is now functionally extinct from Thailand, Myanmar, and southern China; and very scarce in Indonesian Borneo and southern Laos.^[18] Thailand was once the stronghold for this species, but no official records of its occurrence have been made here since 1937.^[19]

The white-shouldered ibis is a lowland specialist and has been observed in various habitats including dry dipterocarp forest, margins of seasonal pools (these pools are known locally as “trapaengs”) interspersed within forest, fallow rice fields, shrubby grasslands, forested lakesides and river margins, gravel and shingle banks at low river levels, sandbanks at wide rivers and, on the Sekong river, sandy islands.^{[3][7][20][14][6]} At least in Indochina, dry dipterocarp forest seems to be the most important habitat.^[2] However, one field study of the local population around the Mekong River in Cambodia found that the ibises nested both in flooded riverine forest and dry inland dipterocarp forest; which was a combination of utilised habitats not observed for any other population.^[3][14]

This species appears to capitalize on traditional local agricultural practices that create and maintain its preferred microhabitats, specifically through grazing and trampling of forest vegetation by livestock such as domestic cattle and water buffalo to create clearings as space for preferential foraging habitat;^[21][20][15] and through wallowing of ungulates in mud to create seasonal pools.^[22] This ibis's reliance on human-mediated activity may be especially strong considering both the marked local population declines of many wild ungulates in the white-shouldered ibis's range in the past few decades and the local extinction of many other species such as the Asian elephant;^[15] although wild boar may still be important contributors to creating seasonal pools through wallowing.^[16] These anthropogenic processes of creating and nurturing suitable habitats may be especially important in the early dry season when such habitat conditions are limited.^[20] Anthropogenic burning practices in dipterocarp forest may also have a similar role to grazing for creating suitable clearings.^[15]

Ecology

Feeding

Pseudibis davisoni on a 2014 stamp of Indonesia

Unlike other sympatric wading birds, the white-shouldered ibis is largely terrestrial in its foraging strategy and has not been seen foraging in open water.^[20] It preferentially forages in muddy seasonal pools covered with short vegetation less than 25 cm high,^[23] on the ground in dry dipterocarp forest preferentially with bare underlying substrate,^[23] in fallow rice fields,^[23] and more occasionally in river channels with large extents of mud and sand.^[9] However, it forages almost exclusively at seasonal pools during the breeding season,^[9] probably due to high densities of refuge-seeking prey residing between the frequent cracks in the dry mud and hence high availability of food to feed to chicks.^[23] With its highly maneuverable, penetrative downcurved bill,^[15] the white-shouldered ibis is well adapted to probing into the cracks potentially harbouring concealed prey.^[22] This specific bill morphology gives the ibis an adaptive feeding advantage over other sympatric waders with straight bills, and is therefore commonly followed and by kleptoparasitic species such as cattle egrets and Chinese pond herons.^[15] Individuals feed singly, in pairs, or in family groups (flocks of up to 14 being reported). Flock size is much larger in the wet (non-breeding) than the dry (non-breeding) season.^[6]

Its diet comprises small invertebrates such as large worms, mole crickets, leeches, insect and beetle larvae; amphibians such as Paddy Frogs Fejervarya limnocharis and frogs of Microhyla species; and eels.^[20][23][6] Although amphibians appear to form the bulk of the diet, the main prey taken at a given place or time may depend on the texture of the underlying substrate^[22] For example, intake rate of invertebrate prey has been found to be significantly higher in saturated than moist or dry grounds; and amphibian intake rate significantly greater in dry than moist, and moist than saturated grounds.^[22] However, dry substrate appears to be most favourable, probably because of the high level of available biomass constituted by large amphibians^[22] (Wright et al. 2013b). Incidentally, there are also unsubstantiated claims of this ibis feeding on fruit.^[6]

After rainfall during the wet season, individuals increasingly use forests and fields as foraging ground instead of pools, probably because of dilution of prey density in the water at pool margins.^[23] Additionally, swamp eels and crabs which are primarily aquatic and occur in saturated substrate have not been identified in white shouldered-ibis diet because these potential prey could easily evade predation by burrowing or swimming away.^[22]

Breeding pairs are demanding in their food requirements, with each pair in Cambodia estimated to utilise nearly two thirds of the total amphibian biomass at a given time for a water hole over an entire breeding season.^[22] Therefore, breeding pairs would need to use multiple waterholes for adequate sustenance over the breeding season to avoid prey depletion at one pool, and the supposedly high resultant intraspecific competition would lead to large dispersion of the breeding population.^[16] Therefore, any conservation recommendations for this species would need to consider a landscape scale approach.^[16]

Breeding

The white-shouldered ibis is a solitary breeder. In its Cambodian stronghold, it nests December–April during the mid- to late dry season November – May^[23][6] in dipterocarp tree canopies.^[9] This breeding strategy contrasts with those in other sympatric water bird species which nest during the wet season or from the late wet to mid- dry seasons.^[15] However, the dry-season breeding in Cambodia is probably synchronized with water drawdown in seasonal pools because of high density of amphibian prey taking refuge in the cracks in the dry mud at pool margins; thereby increasing the potential food availability for chicks and breeding adults.^[6] Different breeding seasons have been reported elsewhere in its range; with February–March in Myanmar when it still persisted here,^[5] September–December in East Kalimantan,^[12] and late August–December in Borneo; with copulation observed in February in this region.^[6]

It builds large nests 10-25m aboveground, composed of twigs and fresh leaves, usually in emergent trees such as Koompasia excels as in Borneo.^[12][24] Both partners continue to add nesting material throughout the breeding season^[12][6] and the same nests may be used in successive years.^[24] It also more occasionally uses abandoned raptor nests.^[12] The clutch contains 2-4 eggs, which are pale blue and hatch asynchronously.^[6] The eggs are incubated for 28–31 days by the female.^[22][6] Available reported egg measurements are 61.0-68.2mm in length and 43.9-46.7mm in width.^[25] The nestling period from hatching to fledging lasts 26–40 days.^[22][6]

Other behaviour

In contrast to their solitary breeding during the dry season, white-shouldered ibises become gregarious in the wet season July–October (non-breeding season); when they roost communally in trees.^[17] During the wet season, large congregations of white-shouldered ibis (up to 185 individuals at a time have been noted) have also been observed foraging on open terrestrial habitats such as abandoned paddy fields^[9] and less frequently at seasonal pools with higher water levels than during the dry season (during breeding).^[23]

The white-shouldered ibis is considered sedentary, but some small movements of just over 5 km between roosting and foraging grounds may occur during the wet season.^[16] During the wet season in Cambodia, there is considerable movement from pools and wet ground in the dipterocarp forest towards drier forest ground, probably due to easy accessibility of terrestrial invertebrate prey compared to evasive amphibians at the pools.^[23] On Borneo, white-shouldered ibises move along large rivers such as the Mahakam in response to large fluctuations in water levels and hence spatiotemporal variations of exposed river banks that serve as suitable feeding grounds.^[6] Additionally, large-scale forest fires in East Kalimantan induced by the El Nino Southern Oscillation in the mid-1990s caused large-scale habitat destruction, leading to appreciable movements of individuals into unburnt forest stretches and thereby resulting in a more aggregated local population distribution.^[26]

Threats and survival

Aspects of the head, by Arnoul in G. Masson (1878)

The white-shouldered ibis is considered one of the most threatened birds of SE Asia.^[2] The largest threats to populations of this species are habitat conversion such as wetland drainage for agricultural developments such as plantations, unsustainable rural development, changing land management through land concessions, and infrastructural developments.^[23][15][6] In the last case for example, the relatively large subpopulations in Lomphat Wildlife Sanctuary and at the unprotected section of the Mekong River could be threatened with proposed dams and encroaching human settlement.^[6] Lomphat Wildlife Sanctuary is also an example region particularly threatened by economic land concessions, through which extensive development could substantially reduce suitable habitat.^[27]

The majority of roosting individuals censused in Cambodia (where the largest known populations occur) during the wet season (about three quarters) have been found to occur outside protected areas, revealing an unfortunate spatial mismatch between important roosting sites and these protected areas.^[17] This may be because most protected areas are situated far from human settlement; and given the ibis's synanthropic nature (reliant on humans for creating suitable microhabitats),^[15] this bird is likely to occur relatively close to settlements;^[15][9] whereby its association with humans may also make it more vulnerable to hunting.^[9] Roosting of white shouldered ibises near to or within Economic Land Concessions will likely be severely affected by loss of foraging habitat and human exploitation.^[16]

Further, the population at the Mekong River may be particularly vulnerable to human exploitation because the ibis's use of both riverine and dryland forest in this region,^[14] thereby potentially exposing it to more human nest exploiters (various workers in the inland forest, and fishers on the river).^[14] This ibis may also be in potential competition with humans during amphibian and swamp eel harvesting during the dry season.^[15]

Alongside direct habitat loss through land development, the white-shouldered ibis's habitat could also be threatened indirectly through modern agricultural mechanization to replace traditional keeping of domestic ungulates that graze and trample on underlying vegetation and wallow in mud to maintain forest clearings and seasonal pools as important foraging ground for ibis.^[23][15] The potentially adverse agricultural changes may be driven by the increasing profitability of mechanised farming.^[15] The hypothesis concerning the importance of ungulates to ibises in creating suitable habitats^[20] has been supported in exclosure experiments which show increased vegetation height and cover in exclosures fenced to bar ungulates compared to unfenced controls.^[20][15] Therefore, the marked decline of traditional farming livelihood practices potentially beneficial to white-shouldered ibis could lead to increased vegetation growth beside pools in clearings, and thereby render these sites unsuitable foraging ground for this ibis.^[15] This may be especially likely considering the local extinction or dramatic decline of many wild ungulate species whose role in ibis habitat creation and maintenance has been largely taken over by human-reared ungulates with equivalent functions.^[15]

Opportunistic exploitation of nests by humans for food through taking eggs and chicks presents another potential threat.^[24] Although human exploitation has been identified as a cause of nest failure, humans are more likely to exploit nests in the late nestling stage; and given that most nest failures have been noted to occur in egg and early nestling stages, natural predation is a more likely cause.^[24] Nest guarding schemes in Western Siem Pang have been implemented to investigate chief causes of nest failure, and no significant difference in nest failure has been found between guarded and unguarded control nests; suggesting that natural causes of mortality are more likely.^[16] Counterintuitively, conservation interventions to protect nests may disturb the nests so as to increase egg and nestling mortality. Such nest guarding schemes have also faced societal problems.^[24]

A potential natural predator of white-shouldered ibis young is the southern jungle crow Corvus macrorhynchos, one individual of which was once observed to remove all eggs of a clutch in the absence of parents, and another of which predated a newly hatched chick.^[24] The ibis may also be threatened by mammalian predators such as civets and yellow-throated marten Martes flavigula, although such predators may be more abundant farther from human settlement due to hunting pressure on these mammals.^[24] Despite increased likelihood of exploitation of nests closer to settlement, these nests may therefore receive increased indirect protection from predators.^[24] Weather poses another potential threat, with some chicks in Cambodia reported as being blown from nests by high winds.^[14]

The white-shouldered population on the Mahakam River in East Kalimantan was severely affected by fire damage to forest during an El Nino Southern Oscillation during the mid-1990s.^[26] Alongside the primary implication of loss of suitable habitat, the fire may have also led to increased riverbank erosion due to fewer trees, decreased water clarity, and changes in water temperature patterns through fewer overhanging branches; all of which may have affected the birds’ ability to successfully forage on riverbanks and gravel beds.^[26]

In relation with humans

Given this species' large apparent reliance on human agricultural activity (both traditional arable and pastoral) to maintain its habitats, it live closer to human habitation than do similar sympatric species such as the giant ibis;^[9] and may even roost and nest in trees near to rice paddies even when in use by people.^[9] However, this ibis is more likely more attracted to the agricultural foraging grounds close to human habitation rather than humans per se.^[9] Although the white-shouldered ibis is exploited opportunistically by humans for food, it is not commercially valued for trade.^[24]

The only captive record for this species is for one specimen that was imported into Thailand from Cambodia in 1989, and held at the Queen's Bird Park at Ayuthhaya near Bangkok in 1990.^[28]

Status

Populations of the white-shouldered ibis declined severely in the late 20th century. Given the scarcity of recorded sightings in the past few decades, the small population size and persistent habitat loss, it has been classified as Critically Endangered by the IUCN.^[6][2] The global population is estimated at 1000 individuals, an estimated 670 of which are mature.^[2] A total of 973 individuals were counted in a nationwide population census in Cambodia in 2013, whereas 30-100 individuals are estimated for the Indonesian portion of the species’ range.^[2]

Etymology

The binomial commemorates William Ruxton Davison.

References

La Blankanuka ibiso, Blankaŝultra ibiso aŭ Davisona ibiso (Pseudibis davisoni) estas specio de vadbirdo de la familio de ibisoj nome Treskiornitedoj. Ĝi loĝas nur ĉe kelkaj lokoj en norda Kamboĝo, suda Vjetnamio, plej suda Laoso kaj Orienta Kalimantano en Indonezio.

La Blankanuka ibiso loĝas en lagoj, lagetoj aŭ flakoj, marĉoj kaj malrapidaj riveroj en malfermaj arbaroj de malaltaj teroj. Ili loĝas ankaŭ en disarbaroj, sekaj aŭ malsekaj herbejoj kaj larĝaj riveroj kun sablecaj aŭ gruzecaj bordoj.

Plenkreskulo estas tipe 75–85 cm longa, kun malhela plumaro, kun distinga hela kolumo kiu deproksime ŝajnas blueca kaj facile kontraste rimarkindas dum ripozo aŭ manĝa piedirado. La kalva kapo estas nigra, la kruroj estas ruĝaj, kaj ĝi havas blankecan makulon en interna flugilo, kiu videblas nur dumfluge aŭ havante malfermajn flugilojn. Ambaŭ blankecaj karakteroj estas tialoj por ambaŭ alternativoj de komuna nomo.

Pro malgranda populacio kaj pliiĝanta habitatoperdo pro lignoproduktado el arbaroj de malaltaj teroj kaj sekigado de humidejoj por agrikulturo, la Blankanuka ibiso estas taksata kiel Draste Endanĝerita ĉe la IUCN Ruĝa Listo de Minacataj Specioj. La nuna monda populacio estis ĉirkaŭkalkulata je malpli da 250, eble tiom malmulte kiom nur ĝis 49, kvankam enketo de 2009 pri la specio kalkulis 310 individuojn.^[1] En 2010 rekordo de 429 estis atingita en Kamboĝo, el kiuj pli da 170 birdoj en la Naturrezervejo Lomphat. Tiu loko estas nune la dua plej grava en la mondo por tiu specio. Kun konata populacio de ĉirkaŭ 200 ekzempleroj okcidento de Siem Pang IBA estus la unua.

La latina scienca nomo estas rememoro al William Ruxton Davison.

Referencoj

• BirdLife International (2004). Pseudibis davisoni. Internacia Ruĝa Listo de Endanĝeritaj Specioj, eldono de 2006. IUCN 2006. Elŝutita 11a Majo 2006. Mapo kaj kriterioj kial tiu specio estas draste endanĝerita.

El ibis de Davison^[1]​ (Pseudibis davisoni) es una especie de ave pelecaniforme de la familia Threskiornithidae^[2]​^[3]​ en gravísimo peligro de extinción.^[4]​ Sus últimas poblaciones (menos de 250 ejemplares) ocupan varias áreas de Laos, Camboya, Vietnam y la parte indonesia de Borneo. No se reconocen subespecies.

Referencias

Pseudibis davisoni Pseudibis generoko animalia da. Hegaztien barruko Threskiornithidae familian sailkatua dago.

Erreferentziak

• World Bird Names

Ikus, gainera

• Pseudibis
• Threskiornithidae

Sininiskaiibis (Pseudibis davisoni) on äärimmäisen uhanalainen iibislintu. Sen kannan pelätään supistuneen muutamiin satoihin yksilöihin.^[1] Hume nimesi lajin William Ruxton Davisonin kunniaksi.

Koko ja ulkonäkö

Sininiskaiibis kasvaa 75–85 senttimetriä pitkäksi. Niskassa on sinisävyinen kaulus. Sen höyhenpeite on kiiltävän musta, niskassa töyhtömäinen harja. Kasvot ovat kaljut ja jalat punertavat.^[2]

Levinneisyys

Sininiskaiibiksiä elää Kambodžassa, Vietnamissa, Laosissa, Indonesiassa.

Lähteet

Pseudibis davisoni

L’Ibis de Davison (Pseudibis davisoni), également appelé ibis à tache blanche ou ibis noir oriental, est une espèce d’oiseaux de la famille des Threskiornithidae.

Nomenclature

Le nom vernaculaire rend hommage à l'ornithologue britannique William Ruxton Davison.

Description

Cet oiseau mesure de 75 à 85 cm de long. Il a un plumage foncé, avec un collier pâle distinctif, d'un beige clair aux tons bleuâtres sur la nuque. La tête est chauve et noire, les pattes sont rouges. La marque blanchâtre qui orne son épaule, cachée quand l'aile est repliée, a donné à l'espèce son nom anglais de White-shouldered Ibis, Ibis à épaule blanchequelquefois francisé en Ibis à tache blanche. On retrouve également l'appellation Ibis noir oriental.

Répartition et habitat

Cet oiseau vit au Cambodge, dans le sud du Vietnam, extrême sud du Laos et dans le Kalimantan oriental en Indonésie.

Il vit près des étendues d'eau, les lacs, les marais et les rivières des forêts dégagées. Il habite également les prairies peu boisées, sèches ou humides et les grands fleuves avec des bancs de sable et de gravier.

Menaces et protection

En raison de la petite taille de la population et de la perte incessante de son habitat, par la coupe des forêts et le drainage des marécages pour l'agriculture, l’Ibis de Davison est considéré comme en en danger critique d'extinction (CR) sur la liste rouge de l'UICN. La population mondiale était estimée par l'UICN à 249 individus adultes, mais un comptage en 2009 a recensé 310, un effectif record pour l'espèce^[1].

Voir aussi

Références taxinomiques

• (en) Référence Congrès ornithologique international : (consulté le 21 mai 2015)
• (en) Référence Zoonomen Nomenclature Resource (Alan P. Peterson) : Pseudibis davisoni dans Pelecaniformes
• (en) Référence Tree of Life Web Project : Pseudibis davisoni
• (en) Référence Catalogue of Life : Pseudibis davisoni (Hume, 1875) (consulté le 18 décembre 2020)
• (fr+en) Référence ITIS : Pseudibis davisoni (Hume, 1875)
• (en) Référence Animal Diversity Web : Pseudibis davisoni
• (en) Référence UICN : espèce Pseudibis davisoni (Hume, 1875) (consulté le 21 mai 2015)

Notes et références

1. ↑ (en) « First coordinated White-shouldered Ibis count dramatically increases known population », sur BirdLife International

L'ibis spallebianche (Pseudibis davisoni (Hume, 1875)) è un uccello della famiglia dei Treschiornitidi.^[2]

Descrizione

Questo uccello è lungo 60–85 cm.^[3] Il piumaggio è prevalentemente bruno nerastro, con un caratteristico collare bianco con sfumature bluastre. Come suggerito dal suo nome comune, le penne copritrici interne presentano una contrastante macchia bianca, spesso non visibile nell'uccello in posizione di riposo. La testa è nera e glabra, con un lungo becco ricurvo verso il basso. Le zampe sono rosse.^[1][4]

Gli immaturi hanno un piumaggio bruno e, a differenza degli adulti, la testa è ricoperta di piume.^[4]

Distribuzione e habitat

Questa specie nidifica in ristrette aree della Cambogia, del Laos e del Kalimantan orientale (Indonesia). In passato nidificava anche nel Vietnam meridionale, dove attualmente è presente solo come visitatore occasionale. In Thailandia è andato incontro ad estinzione locale.^[1]

Popola differenti habitat tra cui le foreste di Dipterocarpaceae, gli stagni stagionali noti localmente come "trapaengs", le risaie abbandonate, le praterie arbustive, i margini boschivi di laghi e fiumi, gli affioramenti di ghiaie, ciottoli e sabbia all'interno dei fiumi.^[5]

Conservazione

La IUCN Red List classifica Pseudibis davisoni come specie in pericolo critico di estinzione (Critically Endangered).^[1] La popolazione attuale è stimata in circa un migliaio di individui.

Note

Baltapilvis ibis (lot. Pseudibis davisoni, angl. White-shouldered Ibis) – ibinių (Threskiornithidae) šeimos paukštis.

Išvaizda

Mažesnis už baltąjį gandrą. Kūno ilgis 75 – 85 cm. Patinai stambesni už pateles, jų snapai ilgesni. Plunksnų danga rudai juodos spalvos. Sparnai ir uodega mėlynai juodos spalvos, žvilgantys. Galva plika, tamsi. Aplink smakrą ir sprandą plikos žydrai baltos odos „apykaklė“. Kojos raudonos. Rainelė oranžiniai raudona. Snapas ilgas, šiek tiek išlenktas į apačią, gelsvai pilkos spalvos. Jauniklių plunksnų danga pilkai ruda. Ant melsvai balto pakaušio yra rudų plunksnų kuokštas. Rainelė pilkai ruda, kojos šviesiai gelsvos, pėdos baltos.

Paplitimas

Aptinkamas Kambodžos šiaurėje ir rytose, Vietnamo ir Laoso pietuose ir Kalimantano rytuose.

Biologija

Biotopas – ežerai, tvenkiniai, pelkės, lėtai tekantys upeliai, šlapynės ir ryžių laukai. Aktyvus dieną. Minta vabzdžiais, sraigėmis, kirmėlėmis, lervomis, buožgalviais, smulkiais vėžiagyviais, driežais, smulkiais žinduoliais ir paukščiais. Grobio ieško pavieniai arba nedidelėmis grupėmis.

Veisiasi pavieniai. Lizdą krauna medžiuose, 5 – 10 metrų aukštyje. Dėtyje 2- 4 kiaušiniai.

Apsaugos būklė

Pasaulinės gamtos apsaugos organizacijos duomenimis yra grėsmingai nykstanti rūšis. populiacijoje yra 670 suaugusių individų. Populiacijos mažėjimo priežastys: miškų kirtimas, šlapynių sausinimas ir medžioklė. Rūšies apsaugos priemonės:

• Indonezijoje, Mianmare, Rytų Malaizijoje yra paskelbtas saugomu paukščiu.
• Kambodžos ornitologai, kartu su vyriausybe, remia paukščio populiacijos (70 individų) Vakarų Siem Pange apsaugą.
• Laoso ir Vietnamo vyriausybės kontroliuoja ginklų savininkus.

Šaltiniai

Nuorodos

• Wildscreen Arkive. White-shouldered ibis (Pseudibis davisoni) anglų k.
• Edge of existence. White-shouldered Ibis. anglų k.

Vikiteka

De witschouderibis (Pseudibis davisoni) is een vogel uit de familie Threskiornithidae (Ibissen en lepelaars). Het is een ernstig bedreigde, endemische vogelsoort die nog voorkomt op twee locaties: zuidelijk Indochina en op Borneo.

Kenmerken

Deze soort ibis is 75 tot 85 cm lang, het is een grote watervogel met een grote brede snavel, een bleke vleeskleurige tot lichtblauw gekleurde naakte huid op de kop en nek, verder witte veren op de borst en buik en zwart van boven en in vlucht een witte vlek op de verder zwarte bovenvleugel (van daar de naam).^[2][3]

Verspreiding en leefgebied

De witschouderibis had een veel grotere verspreiding binnen Indochina en Borneo, maar is in de loop van de twintigste eeuw terug gedrongen tot nog een paar gebieden. Rond 2012 komt deze ibis nog voor in zuidelijk Indochina in Zuid-Laos en vooral Cambodja waar het belangrijkste leefgebied ligt in een draslandnatuurgebied in de provincie Ratanakiri. Een kleiner deel van de wereldpopulatie bevindt zich op Borneo op Oost-Kalimantan aan de bovenloop van de Mahakam. Het leefgebied bestaat uit draslanden langs grote rivieren in combinatie met ongerept regenwoud.

Status

De witschouderibis heeft een versnipperd verspreidingsgebied en daardoor is de kans op uitsterven aanwezig. De grootte van de populatie werd in 2013 door BirdLife International geschat op minstens 970 individuen. Het leefgebied van deze ibis wordt bedreigd door de aanleg van dammen, drooglegging van moerassen, ontbossing, jacht, verstoring en factoren die nog niet geheel duidelijk zijn. Om deze redenen staat deze soort als ernstig bedreigd (kritiek) op de Rode Lijst van de IUCN.^[1]

Davisonibis^[2] (Pseudibis davisoni) är en utrotningshotad fågel i familjen ibisar inom ordningen pelikanfåglar.^[3]

Utseende

Davisonibisen är en stor (75-85 centimeter) och mör ibis med ett distinkt halsband, blåaktigt på nära håll ock blekt på håll. Den har ett svartaktigt naket huvud, dovt röda ben och en vitaktig fläck på inre delen av framvingen. Liknande brahminibisen har en röd fläck i nacken och saknar halsbandet, medan den likaledes utrotningshotade jätteibisen är mycket större, med enfärgat blekare mörkbandat på huvud, övre delen av halsen, vingtäckarna och armpennorna.^[1]

Utbredning och status

IUCN kategoriserar arten som akut hotad.^[1] Fågeln har under 1900-talet försvunnit från många områden där den tidigare förekom. I 2010 års rödlista uppges arten förekomma främst i norra och östra Kambodja. Därtill förekommer den i allra sydligaste Laos och på Borneo, samt sällsynt i södra Vietnam (ej häckande). Den antas vara utdöd i Thailand och har troligen försvunnit även från Myanmar (Burma). Andra områden som arten historiskt rapporterats från är Sarawak, sydvästra Yunnan i Kina och centrala Vietnam. En orsak till att arten gått tillbaka är habitatförlust.^[1]

Namn

Fågelns svenska och vetenskapliga artnamn hedrar den brittiske fältornitologen William Ruxton Davison (d. 1893) som arbetade som samlare för Allan Octavian Hume som beskrev arten.^[4] Han var även curator för Raffles Museum i Singapore 1887-1893.^[4]

Noter

1. ^ [a b c d] Birdlife International 2015 Pseudibis davisoni Från: IUCN 2015. IUCN Red List of Threatened Species. Version 2015.4 www.iucnredlist.org. Läst 2016-02-01.
2. ^ Sveriges ornitologiska förening (2018) Officiella listan över svenska namn på världens fågelarter, läst 2018-02-14
3. ^ Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood (2015) The eBird/Clements checklist of birds of the world: Version 2015 http://www.birds.cornell.edu/clementschecklist/download, läst 2016-02-11
4. ^ [a b] Jobling, J. A. (2016). Key to Scientific Names in Ornithology. Ur del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2016). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. Hämtad från www.hbw.com.

Externa länkar

• Wikimedia Commons har media som rör davisonibis.
  Bilder & media
• Wikispecies har information om Pseudibis davisoni.
  Artförteckning
• Bilder och filmer på Internet Bird Collection
• Läten på xeno-canto.org

* Pseudibis papillosa davisoni

Pseudibis davisoni, Threskiornithidae familyasında yer alan bir aynak türüdür. Kamboçya'nın kuzeyinde, Vietnam'ın güneyinde, Laos'un en güneyinde ve Endonezya'da Doğu Kalimantan'da çok az yerde bulunur. Epitet adı Britanyalı ornitolog William Ruxton Davison'a ithafen verilmiştir.

Fiziksel özellikleri

Erişkinlerin boyu 75 ila 85 cm. arasındadır. Tüyleri koyu renklidir. Boyunlarında yakın mesafeden mavimsi görünen soluk şerit ayırt edici özelliğidir. Tüysüz başı siyah renklidir. Bacakları kırmızıdır. Kanadının ön iç tarafında beyaz leke bulunur.

Dağılımı ve yaşam alanı

Göllerde, bataklıklarda, yavaş akan akarsu kıyılarında ve açık ormanlıklarda yaşar. Günümüzde küresel popülasyonunun 250'den az olduğu ve muhtemelen 49 civarı olduğu tahmin edilmektedir ancak 2009 yılında yapılan bir saha araştırmasında 310 birey sayılmıştır.^[1] 2010 yılında ise Kamboçya'da 429 kuş bulunmuştur.

Notlar

Cò quăm cánh xanh hoặc cò quăm vai trắng là một loài chim trong họ Threskiornithidae.^[2] Loài này xuất hiện ở một vài nơi thuộc miền bắc Campuchia, đồng bằng Nam Bộ, miền nam Lào và Đông Kalimantan của Indonesia.

Chúng sống gần các ao, hồ, đầm lầy và các dòng sông có nước chảy chậm trong các khu rừng đất thấp trống trải. Nó cũng sống trong các vùng đồng cỏ ẩm hoặc không, rừng cây thưa và các con sông rộng có cát dãi cát và sạn.

Chú thích

Tham khảo

Bài viết liên quan đến chim này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn.

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