Metopidius Indicus

The bronze-winged jacana (''Metopidius indicus'') is a wader in the family Jacanidae. It is found across South and Southeast Asia and is the sole species in the genus ''Metopidius''. Like other jacanas it forages on lilies and other floating aquatic vegetation, the long feet spreading out its weight and preventing sinking. The sexes are alike but females are slightly larger and are polyandrous, maintaining a harem of males during the breeding season in the monsoon rains. Males maintain territories, with one male in the harem chosen to incubate the eggs and take care of the young. When threatened, young chicks may be carried to safety by the male under his wings.

Taxonomy and systematics

The bronze-winged jacana was formally described by the English ornithologist John Latham in 1790 and given the binomial name ''Parra indica''. He placed it in the genus ''Parra'' along with all the other jacanas. Latham had earlier included the species in a supplement to his ''A General Synopsis of Birds'' but had not coined a scientific name. The present genus ''Metopidius'' was introduced by the German zoologist Johann Georg Wagler in 1832. The bronze-winged jacana is the only species within the genus. The name ''Metopidius'' is from the Ancient Greek word ''metōpidios'' meaning "on the forehead", referring to the frontal lappet. The specific epithet ''indicus'' is the Latin word for "Indian". There are no recognised subspecies.

Like other jacanas it has 10 tail feathers and the oil gland is tufted. Many jacana species have a carpal spur that is used in territorial fights. In some species the spur is reduced but the wing bones are modified. The carpal spur is reduced to a tubercle in the bronze-winged jacana. In the genera '' Actophilornis'', and ''Irediparra'' the radius bone is flattened and blade-like (and associated with a reduced spur) and is thought to be an adaptation either for territorial combat, or for brooding eggs and carrying young under the wings. In ''Metopidius'', the radius curves and diverges to form a broad gap between the radius and ulna. Male jacanas, based on observations in the African jacana, incubate eggs and move their forewings under the eggs so as to hold them between the body and the wing. This behaviour known as wing-brooding may be aided by the flattened radius bone.

Description

Bronze-winged jacanas are rail-like, large, short tailed birds that appear dark at a distance except for the supercilium. They are in length. The sexes are similar but the females are slightly larger than the males. The wings are bronzy brown with a green sheen and have a reduced tubercular carpal spur. The head, neck and breast are black and contrast with the broad white supercilium that runs from over the eye to the back of the neck. The lower back and tail coverts are chestnut. The tail is stubby and reddish brown with black terminal band. The greenish yellow bill has a red-base to the upper mandible. A lappet or frontal shield extends up over the forehead and is reddish purple. The legs are greenish. The toes are long and the straight and the elongated nail on the hind toe is longer than the toe. Downy chicks are light brown with a dark stripe running down the nape. Young birds have brown upperparts, a rufous crown, white underparts, a buff foreneck, an undeveloped frontal shield, and may have a dull supercilium. Adults can be confused at a distance with the common moorhen (which is found in similar habitat) and with the watercock and while young can appear similar to the young of the pheasant-tailed jacana, they lack the black necklace seen in that species.

Distribution and habitat

The species is widely distributed across the Indian Subcontinent (but not Sri Lanka or western Pakistan) and Southeast Asia mainly in low elevations. Both this species and the pheasant-tailed jacana can occur in the same habitat. It is sedentary apart from seasonal dispersal in response to drought and rains. They are able to use wetlands covered in introduced weeds such as water hyacinth

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