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Monday 28 November 2016

25-11-2016 INLE LAKE, MYANMAR - PHEASANT TAILED JACANA (Hydrophasianus chirurgus)



This jacana breeds on floating vegetation during the rainy season. In southern India, it breeds in the monsoon season, June–September. It is polyandrous; one female may lay up to ten clutches in a single season that are raised by different males. Female court males with flight displays around the males and with calling. The female builds a nest on floating vegetation made of leaves and stalks of plants with a depression in the centre. A single clutch consists of four glossy black-marked dark-olive-brown eggs (occasionally an egg in a clutch may be an odd pale sea-green in colour which are laid in the mornings at 24 hour intervals. When an egg is removed at the one- or two-egg stage, the nest is torn down and a new one built, whereas a removal at the three-egg stage does not result in replacement. Once the clutch of four is laid, the male begins incubation and the female leaves to court a different male. In a study in Thailand it was found that it took a female 17 to 21 days to lay the next clutch. A study in China found females taking 9–12 days and laying nearly 7 to 10 clutches in a season.[18] Males may move or drag eggs around by holding them between the bill and breast or between the wings and body. They may also push and float the eggs over water and onto nearby vegetation platforms when disturbed. Nests may be moved to distances of about 15 metres.  Males near the nest may perform broken-wing and rodent-run displays to distract predators. The eggs are incubated for 26 to 28 days. During the first few days of incubation, the female defends the nest, chasing other waterbirds that may approach too close by flying at them. In close territorial combat they lock bills and strike simultaneously with both wings. Males actively forage in the morning and afternoon and tend to sit at the nest during the hottest part of the day. The downy nidifugous chicks freeze when threatened or when the male indicates alarm and may lie partly submerged with just the bill out of water.

Eggs may be preyed on by pond herons, while chicks may bet taken by birds of prey such as black-winged kites. The trematode parasite Renicola philippinensis was described from the kidney of a pheasant-tailed jacana in the New York Zoological Garden while Cycloceolum brasilianum was recorded in India. The bird louse species Rallicola sulcatus has been described from this species; it looks very similar to Rallicola indicus from the bronze-winged jacana. Another bird louse known from the species is Pseudomenopon pilosum.








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