Current view: Data table and detailed info
Closely related to C. galerita and C. ophthalmica. Previous recognised taxon included subspecies citrinocristata (del Hoyo & Collar 2014), but this now split as Citron-crested Cockatoo (which see). Subspecies abbotti strikingly large (except in bill size) (3), with small, pale brownish-yellow ear-covert patch (2). Subspecies djampeana and occidentalis generally regarded as synonyms of nominate subspecies and parvula, respectively, but new evaluation indicates real morphological differences and even possible subspecific division within djampeana (Collar & Marsden 2014). Five subspecies recognized.
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: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip.
Red List criteria met
Red List history
IUCN Red list criteria met and history
||not a migrant
|Land mass type
Population justification: A recent estimation of the population of each subspecies produced as a result of intensive surveys throughout the species's range between 2016 and 2019 (Reuleaux et al. in prep.) suggests the following: nominate, on Sulawesi and its satellites, 27-105 individuals; parvula, on Timor, Rote, Semau, 430-990 individuals; paulandrewi, Tukangbesi islands, 81-170 individuals; djampeana, Flores Sea islands, 61-156 individuals; occidentalis, Nusa Penida and Lombok-Alor (although extinct on many islands), 1,200-1,700 individuals; and abbotti, 17-22 individuals. In total, the population is estimated to number 1,800-3,140, or 1,200-2,000 mature individuals, with the best estimate near the higher end of the range. This total is suspected to be only a small percentage of that present three generations ago, when the species was still widespread throughout Sulawesi and large numbers still occurred throughout the Lesser Sundas. The rate of reduction over this time is suspected to have been between 80-90%. Future declines are likely to be at a far slower rate as the majority of the population is now concentrated in protected areas, but trapping continues and there are several islands at imminent risk of losing their remaining few individuals.
Trend justification: This species has declined extremely rapidly owing to international trade in the species and to a lesser extent the widespread deforestation within its range. The size of its population before the rapid trade rise is poorly understood, but that >5,000 were imported to Singapore annually throughout the 1980s (Cahill et al. 2006) is strongly indicative of a population formerly substantially greater than the contemporary estimation of 1,200-2,000 birds, especially when considering large numbers were probably lost in transit before making it to Singapore (A. Reuleaux in litt. 2021). However, internal and international trade is thought to continue (e.g. Andersson et al. 2021). The species has become extinct on a number of islands in Nusa Tengarra, and other populations have been decimated. For example, nominate sulphurea persists on Sulawesi with a much-diminished population of c.50 birds in South-east Sulawesi province, having formerly been widespread across the island. Similarly, subspecies abbotti persists with just 17-22 birds left.
Over the last three generations (since 1978), the population is suspected to have decline by 80-90%. Declines were also documented even where trade was not so obvious, such as on Komodo where a rapid decline was reported up to 2005 (Imansyah et al. 2016). The population on Komodo (comprising c.1,100 individuals, c.35% of the global population) is now believed to be stable thanks to protections in Komodo National Park (Reuleaux et al. 2020), such that future declines of the global population are estimated to be slower. However, the current and future rate of forest cover loss in the current occupied and probably occupied range (based on the estimated mean annual rate over the most recent five years, per Global Forest Watch 2021) is projected to be 16.1% over three generations. Consequently, even if trapping is successfully halted in the remnant populations, it is inferred that the population will continue to decline due to the species’s dependence on large trees for nesting. The species is therefore projected to decline over 30-49% over the next three generations. However, any declines in the Komodo population would likely see this rate increase once again, and from a much smaller starting population.
Important Bird and Biodiversity Areas (IBA)
BirdLife International (2023) Species factsheet: Cacatua sulphurea. Downloaded from
http://datazone.birdlife.org/species/factsheet/yellow-crested-cockatoo-cacatua-sulphurea on 06/06/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://datazone.birdlife.org on 06/06/2023.