Yellow-crested Cockatoo Cacatua sulphurea


Taxonomic note
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.

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:

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
A2bcd+4bcd A2bcd+4bcd A2bcd+3bcd+4bcd

Red List history
Year Category Criteria
2021 Critically Endangered A2bcd+4bcd
Species attributes

Migratory status not a migrant Forest dependency medium
Land mass type Average mass -

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 965,000 medium
Number of locations 15-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 1200-2000 medium estimated 2019
Population trend decreasing poor inferred -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 80-90 - - -
Number of subpopulations 10-100 - - -
Percentage in largest subpopulation 1-89 - - -
Generation length (yrs) 14.3 - - -

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.

Country/territory distribution
Country/Territory Presence Origin Resident Breeding Non-breeding Passage
China (mainland) extant introduced yes
Hong Kong (China) extant introduced yes
Indonesia extant native yes
Singapore extant introduced yes
Timor-Leste extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Arable Land suitable non-breeding
Artificial/Terrestrial Plantations suitable resident
Forest Subtropical/Tropical Dry major resident
Forest Subtropical/Tropical Mangrove Vegetation Above High Tide Level suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Shrubland Subtropical/Tropical Dry suitable resident
Shrubland Subtropical/Tropical Moist suitable resident
Altitude 0 - 1000 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Shifting agriculture Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Livestock farming & ranching - Agro-industry grazing, ranching or farming Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Very Rapid Declines High Impact: 8
Species mortality
Biological resource use Hunting & trapping terrestrial animals - Persecution/control Timing Scope Severity Impact
Past, Unlikely to Return Minority (<50%) Slow, Significant Declines Past Impact
Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Unspecified species Timing Scope Severity Impact
Ongoing Unknown Negligible declines Unknown
Competition, Reduced reproductive success
Invasive and other problematic species, genes & diseases Problematic native species/diseases - Varanus komodoensis Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Species mortality
Pollution Agricultural & forestry effluents - Herbicides and pesticides Timing Scope Severity Impact
Ongoing Minority (<50%) Unknown Unknown
Ecosystem degradation

Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - non-trivial recent
Pets/display animals, horticulture - - international non-trivial recent

Recommended citation
BirdLife International (2023) Species factsheet: Cacatua sulphurea. Downloaded from on 06/06/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from on 06/06/2023.