Data Zone
Justification of Red List category
This coucal's population and range are small, declining and severely fragmented as a result of the destruction and degradation of humid forest. It therefore qualifies as Vulnerable.
Population justification
The population is unlikely to number more than a few thousand individuals, based on available records and survey results, thus there are assumed to be fewer than 10,000 mature individuals. It is placed in the band 2,500-9,999 mature individuals. This equates to 3,750-14,999 individuals in total, rounded here to 3,500-15,000 individuals.
Trend justification
On-going illegal logging of wet zone forests is the principal threat to this species and is suspected to be driving a continuing, moderate population decline.
Centropus chlorohynchos is endemic to Sri Lanka, where it is confined to the wet zone in the south-west of the island (BirdLife International 2001). Its population is poorly known, but appears to have declined and become increasingly fragmented since the late 19th and early 20th century, and it is absent from some sites where it formerly occurred. It is unlikely that its population exceeds a few thousand individuals.
It is found in high-stature, undisturbed, wet zone forests with a dense understorey (often of bamboo) mainly below 760 m. There are a few records from human-modified habitats surrounded by forest but it appears generally intolerant of habitat modification. It will use forest corridors to move between good quality habitat patches but many of these have been cleared. It feeds on a wide variety of invertebrates and also frogs, lizards and fruit, and is thought to breed from January-July, and possibly at other times of year.
The main threat is the extensive clearance and degradation of forests, particularly in the wet zone, through logging, fuelwood-collection, conversion to agriculture and tree plantations, gem mining, settlement and fire. Some protected forests continue to be degraded and suffer further fragmentation, for example Ingiriya Forest Reseve, where it is declining because of illegal logging. Competition with Greater Coucal C. sinensis, which occurs in logged and disturbed areas, may be contributing to its decline.
Conservation Actions Underway
It is legally protected in Sri Lanka, and a moratorium was passed in 1990 to protect wet zone forests from logging. It occurs in several national parks and forest reserves, most notably Sinharaja National Heritage Wilderness Area. A survey of the biodiversity of 200 forest sites was carried out during 1991-1996.
43 cm. Medium-large coucal with blackish head, body and tail and maroon-brown wings. Green bill can appear ivory. Similar spp. Greater Coucal C. sinensis has black bill and shows more striking contrast between chestnut wings and black body. Voice Sonorous mournful hooo-poop or hooo-poo-poop, the poop lower-pitched than the hooo. Sometimes utters a single note chugh reminiscent of a call given by the endemic Toque macaque Macaque inica.
Text account compilers
Benstead, P., Bird, J., Crosby, M., Peet, N., Taylor, J. & Symes, A.
Contributors
de Silva Wijeyeratne, G.
Recommended citation
BirdLife International (2024) Species factsheet: Green-billed Coucal Centropus chlororhynchos. Downloaded from
https://datazone.birdlife.org/species/factsheet/green-billed-coucal-centropus-chlororhynchos on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/12/2024.