Cigogne épiscopale

Identification

The woolly-necked stork is a medium-sized stork at 75–92 cm tall. The iris is deep crimson or wine-red. The stork is glistening black overall with a black "skull cap", a downy white neck which gives it its name. The lower belly and under-tail coverts are white, standing out from the rest of the dark coloured plumage. Feathers on the fore-neck are iridescent with a coppery-purple tinge. These feathers are elongated and can be erected during displays. The tail is deeply forked and is white, usually covered by the black long under tail coverts. It has long red legs and a heavy, blackish bill, though some specimens have largely dark-red bills with only the basal one-third being black. Sexes are alike. Juvenile birds are duller versions of the adult with a feathered forehead that is sometimes streaked black-and-white. The African birds are described as having the edges of the black cap diffused or with a jagged border compared to a sharp and clean border in the Asian birds. Sexes are identical, though males are thought to be larger. When the wings are opened either during displays or for flight, a narrow band of very bright unfeathered skin is visible along the underside of the forearm. This band has been variously described as being "neon, orange-red", "like a red-gold jewel", and "almost glowing" when seen at close range.<p>Small nestlings are pale grey with buffy down on the neck, and a black crown. At fledging age, the immature bird is identical to the adult except for a feathered forehead, much lesser iridescence on feathers, and much longer and fluffier feathers on the neck. Newly fledged young have a prominent white mark in the center of the forehead that can be used to distinguish young of the year.<p>English common names for this species include the white-necked stork, white-headed stork, bishop stork and parson-bird. More recently, the African and Asian populations are considered to be two different species, the African woolly-necked stork and the Asian woolly-necked stork. This is based purely on geographical isolation, but there is no morphological or phylogenetic evidence yet to support this split.

Taxonomie

The woolly-necked stork was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1780 in his Histoire Naturelle des Oiseaux from a specimen collected from the Coromandel Coast of India. The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Ardea episcopus in his catalogue of the Planches Enluminées. The woolly-necked stork is now placed in the genus Ciconia that was erected by the French zoologist Mathurin Jacques Brisson in 1760. The genus name Ciconia is the Latin word for a "stork"; the specific epithet episcopus is Latin for "bishop".<p>Two subspecies are recognised:<p>The online edition of the Handbook of the Birds of the World , the IOC, Clements, and the IUCN have reclassified the African race, C. e. microscelis, as a separate species, the African woolly-necked stork (C. microscelis), with the remaining two subspecies becoming the Asian woolly-necked stork. The Handbook and other sources of taxonomic lists use geographical separation as the sole basis for elevating the three subspecies into two species, and this assumption requires to be tested using more definitive methods such as genetics.

Nom scientifique

Ciconia episcopus

Autorité

(Boddaert, 1783)

Ordre

Ciconiiformes

Famille

Ciconiidae

Genre

Ciconia

Répartition et habitat

It is a widespread tropical species which breeds in Asia, from India to Indonesia. It is a resident breeder building nests on trees located on agricultural fields or wetlands, on natural cliffs, and on cell phone towers. They use a variety of freshwater wetlands including seasonal and perennial reservoirs and marshes, crop lands, irrigation canals and rivers, but are mostly seen in agricultural areas and in wetlands outside protected areas across south Asia and Myanmar. They are attracted to fires in grasslands and crop fields where they capture insects trying to escape the fire. They use ponds and marshes inside forests in Asia, especially in south-east Asia where they use grassy and marshy areas in clearings in several forest types. In India, they are an uncommon species in coastal habitats. They use coastal areas in Asia with birds in Sulawesi observed to be eating sea snakes. In an agricultural landscape in north India, woolly-necked storks preferred fallow fields during the summer and monsoon seasons, and natural freshwater wetlands during the winter. Here, irrigation canals were preferentially used during winters when water levels were low, and birds avoided crop fields in all seasons. Assisted by construction of new irrigation canals, this species is spreading to arid areas like the Thar Desert in Rajasthan, India. Across south Asia, Asian woolly-necked storks largely use agricultural landscapes with more numbers seen using unprotected wetlands relative to the amount of wetlands on the landscape, and a majority of individuals use agricultural crops. In Haryana, north India, they nest on trees planted along crop fields and irrigation canals as part of traditional multifunctional agroforestry and generally avoid trees close to human settlements.<p>Individuals of this species have been sighted at altitudes of 3,790 m above sea level in China (Napahai wetland), and 3,540 m above sea level in Nepal (Annapurna Conservation Area).

Migration

Espèce sédentaire

Comportement

Mode de migration: Espèce sédentaire.

Conservation

Tendance de la population: en déclin.

Tendance de la population

en déclin