Current view: Data table and detailed info
Taxonomic note
Previously treated as a subspecies of Cuculus saturatus (del Hoyo & Collar 2014), C. optatus is split once more following Xia et al. (2016) who showed that these are two vocally distinct taxa after a previous paper had suggested they were undifferentiated in voice. Score 4 for the difference (3-4 notes vs 2 = a 50-100% increase) in voice, plus 2 for difference in size (optatus male wing mean 218.4, saturatus 183.4: Erritzøe et al. 2012: 469-470), 1 for slightly broader black barring on chest to belly which extends to vent. Name horsfieldi used for Palearctic populations, but this has been shown to be inappropriate and name optatus reinstated (Payne 2005). This taxonomic concept was previously recognised between 2006 and 2014 following Payne (2005). Prior to that treatment, C. lepidus (Payne 2005, del Hoyo & Collar 2014), C. saturatus and C. optatus had been included within C. saturatus following Sibley and Monroe (1990, 1993). Monotypic.
Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2021. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip.
Payne, R. B. 2005. The cuckoos. Oxford University Press, Oxford, U.K.
IUCN Red List criteria met and history
Red List criteria met
Red List history
| Migratory status |
full migrant |
Forest dependency |
medium |
| Land-mass type |
|
Average mass |
- |
Population justification: Densities of 0.1-0.5 singing males/km2 have been recorded in Russia (Hagemeijer and Blair 1997). Assuming an equal sex ratio and 20-40% occupancy of its EOO breeding range, the population size is suspected to number 500,000-5,000,000 mature individuals; the true figure is likely to be at the highest end of this estimate given that the European breeding population is estimated at 120,000–155,000 calling or lekking males, or 240,000–310,000 mature individuals (BirdLife International in prep.). National population estimates include: c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in China; c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Taiwan; c.100-10,000 breeding pairs and c.50-1,000 individuals on migration in Korea; c.100-100,000 breeding pairs and c.50-10,000 individuals on migration in Japan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Russia (Brazil 2009).
Trend justification: Remoting sensing data on tree cover lost indicate that c.6-8% of forest cover has been lost from the species's breeding range over the past three generations (11 years; Global Forest Watch 2021). Its reliance on undisturbed forests for breeding is unknown but the majority of its host species are moderately forest-dependent, and the present species is reported to be outcompeted by C. cuculus in more open habitats in parts of its range (Erritzøe et al. 2012). Forest loss may be anticipated to accelerate with forest fires in Siberian forests becoming more frequent (and intense) as a consequence of climate change. This should continue to be monitored closely. Forest loss is occurring at a similar rate (5-7% over three generations) in this species's non-breeding range, which may equally be causing some decline; however, this species has been noted wintering in open and heavily degraded habitats, and so these declines are thought to be less significant. Overall, the species is suspected to be declining at a rate of 1-10% over three generations.
Country/territory distribution
Important Bird and Biodiversity Areas (IBA)
Recommended citation
BirdLife International (2024) Species factsheet: Oriental Cuckoo Cuculus optatus. Downloaded from
https://datazone.birdlife.org/species/factsheet/oriental-cuckoo-cuculus-optatus on 22/12/2024.
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 22/12/2024.
