Green Billed Coucal
Sri Lanka Green-billed Coucal "Centropus chlororhynchos" (Blyth, 1849)
The Green-billed Coucal is special amongst Sri Lanka’s endemic birds. Its range today, continues to decline. The continuous destruction of lowland wet zone forest, together with the coucals’ avoidance of disturbed habitats, has brought this species close to the brink. It is now confined to a very few localities in the wet zone, below 800 meters altitude.
The Green-billed coucal could be mistaken for the (very) common coucal, but is most easily differentiated from that species by its dark, reddish-brown wings, the pale-green bill (ivory during breeding), and the purple sheen on its head and neck (the sexes are alike). Adults measure up to about 45cm in length. Fledged young have a slate grey iris.
Of all the forest birds, the green-billed is possibly the most difficult to see, invariably confining itself to the undergrowth. Like the common coucal, after heavy rain and in the morning, green-bills come out into open areas to dry out their plumage. The species is most easily identified and located from its loud, booming call, made during the mornings and evenings. The call has been described as ‘similar in character to that of the common coucal but is usually only two or three-syllabled and deeper, with a sonorous, mournful quality. Both sexes call, but the males call more often. The frequency of calls increases during the breeding seas° these birds feed on small animals such as lizards, beetles, butterflies, spiders, snails, and grasshoppers.
Sri Lanka Green-billed Coucal – Centropus chlororhynchos
Little is known of the breeding behaviors of the Green-billed coucal. The nest has been described “as being domed, made of sticks, twigs, roots, and grass, lined with green leaves and supple green twigs”. It is normally placed among the thorny canebrakes, 1.2-1.5 meters from the ground. Two or three chalky white eggs measuring about 34.7×27 mm are thought to be laid, and the breeding season is believed to last from January to July.