Yellow-crested Cockatoo Cacatua sulphurea


Justification of Red List Category
This cockatoo has suffered (and may continue to suffer) an extremely rapid population decline, owing to unsustainable trapping for the cagebird trade. It therefore qualifies as Critically Endangered.

Population justification
Based on recent surveys within various parts of the species's range, C. Trainor in litt. (2016) has estimated the global population at fewer than 3,000 individuals: Sumba perhaps as few as 563 on Sumba in 2012 (Burung Indonesia in prep), 500 on Komodo, 200-300 on Timor Leste, 200-300 on Sulawesi, 20-50 on West Timor (with a potential sighting of 60 individuals in 2013), 40-70 on Flores, 50-100 on Sumbawa, 100 on Rinca and c.700 other birds in total. This total is roughly equivalent to 2,000 mature individuals, and so the global population size is best placed in the range 1,000-2,499 mature individuals.

Trend justification
This species has declined extremely rapidly owing to international trade in the species and widespread deforestation within its range. Declines have been documented in recent years, even where trade is not so obvious, such as on Komodo where an estimated decline of 60% occurred between 2000 and 2005.

Distribution and population

This species is endemic to Timor-Leste and Indonesia, where it was formerly common throughout Nusa Tenggara (from Bali to Timor), on Sulawesi and its satellite islands, and the Masalembu Islands (in the Java Sea). It has undergone a dramatic decline, which is still ongoing, particularly in the last quarter of the 20th century, such that it is now extinct on many islands and close to extinction on most others. Sumba appears to support the largest remaining population, tentatively estimated in 1992 at c.3,200 birds, but was reported to be declining by perhaps 500 birds annually, with just 10% of the island still forested in 34 fragments (Walker et al. 2005), and extrapolations across remaining forest cover from numbers in six IBAs suggesting just 563 birds in 2012 (Burung Indonesia in prep.). Other significant populations are on Komodo (c.500 individuals, but potentially now fewer), Sulawesi and Buton (combined remaining population of perhaps 200 individuals but almost extirpated from Buton by 2009 [Anon. 2012, Waugh 2013]), Sumbawa (107 birds in a recent census [Anon. 2013], although the population may be smaller [C. Trainor in litt. 2016]), Tanajampea (only 14 birds were located in a targeted survey in 2015 and there are likely to be fewer than 100 individuals [Bashari and Arndt 2016, H. Bashari in litt. 2016]), Moyo, Timor-Leste (Trainor et al. undated), Alor (a loose flock comprising c. 18 birds was observed in 2009), West Timor (potential sighting of 60 individuals in 2013 [per C. Trainor in litt. 2016]), Flores, Rinca (with a sighting of 69 counted in West Flores with the birds arriving from Rinca [Aziz 2014]) and Pantar (one or two cage birds captured on Pantar [F. Verbelen in litt. 2012]). Tiny populations of just a few individuals also exist in the Tukangbesi Islands, on Oroho Island (a satellite of Wangi Wangi Island) and on Lintea Selatan (a satellite of Tomea Island) (D. Kelly in litt. 2009), on Roti island (near Timor) (Johnstone and Jepson 1996, Trainor 2005, F. Verbelen in litt. 2012), and Kadatua Island west of Buton (Anon. 2012).

The Komodo population alone (where poaching is more covert) declined by an estimated 60% between 2000-2005 (Imansyah et al. 2005). Its current status on several small islands is unclear, but surveys of Masakambing in the Masalembu Islands in 2008 found only ten individuals remaining of race abbotti (Anon 2008, Metz et al. 2009, Nandika et al. 2009), with only eight recorded in 2009 (Nandika et al. 2009), but increasing slightly to 11 in 2010 and 13 in 2011 (Anon. 2012). Local information suggests that the species was extirpated from Masalembu Island in 1987, owing largely to the trapping and killing of birds that accompanied the exploration of the archipelago in the late 1980s (Nandika et al. 2009). A feral population of several hundred birds exists in Hong Kong, outside of the species's natural range. It is likely extirpated from Lombok (F. Verbelen in litt. 2012).


This species inhabits forest (including evergreen, moist deciduous, monsoon and semi-evergreen), forest edge, scrub and agriculture up to 500 m on Sulawesi, and 800 m (sometimes 1,500 m) in Nusa Tenggara. Previously thought to be heavily dependent on closed-canopy primary forest, on Sulawesi it is a bird of forest savanna and more open habitats and does not occur in primary forest (Anon. 2012), and on Sumba the availability of nesting trees is critical but the species may not require large areas of forest (D. Mulyawati in litt. 2012). However, this may be an artifact of the lack of appropriate habitat leading to the species using less than optimal areas (C. Trainor in litt. 2016), and surveys on Sumba only found roost trees in primary forest (Djawarai et al. 2014). Breeding takes place from September to May on Sumba (Walker et al. 2005). It nests in tree cavities with specific requirements, tending to use a chink in the trunk or branch, or a pre-existing nest-hole made by another species, often in dead, snagged or rotting trees (Nandika et al. 2009). On Masakabing Island, observations suggest that the species's favoured foods include male fruits of Artocarpus communis, fruit and flowers of Cocos nucifera (coconut palm), young leaves and flowers of Ceiba petandra, mangroves, and male flowers of Brassus sudaica, with consumption of the fruit, flowers and seeds of at least six other species observed (Metz et al. 2009). Nesting has been observed in C. nucifera, A. communis, C. petandra, Tamarindus indica and Avicennia spp. (Nandika et al. 2009).


Its precipitous decline is almost entirely attributable to unsustainable exploitation for internal and international trade. Illegal trapping continues in many areas including Rawa Aopa Watumohai National Park, Buton and Kadatua Islands (Anon. 2012), but has reportedly been reduced significantly on Sumba (D. Mulyawati in litt. 2012). Large-scale logging and conversion of forest to agriculture across its range has exacerbated the decline, and the use of pesticides since around 1989 is a further potential threat. At least formerly, the species was regarded as a crop pest, and consequently persecuted; and it may also be hunted for fun (H. Bashari in litt. 2016). A shift from cultivation of corn, papaya and other foodstuffs to rice on Sumba may consequently have reduced food availability for the species (Nandika and Agustina 2012). High rainfall years appear to limit productivity considerably, resulting in very low recruitment. Conversely, rainfall on Komodo has been low in recent years leading to limited availability of water sources. Juvenile Komodo Dragons Varanus komodensis pose a threat to nestlings on Komodo (Nandika and Agustina 2012). Competition for cavity nest sites with other parrots and owls in large trees (those targeted by logging activities) leads to low productivity (Walker et al. 2005). On the smaller islands of Roti, Alor and Pantar, enforcement of hunting and trading regulations is low (F. Verbelen in litt. 2012).

Conservation actions

Conservation and Research Actions Underway
CITES Appendix I (2005). A cooperative recovery plan has been developed and adopted, and an update was prepared in 2012 (D. Mulyawati in litt. 2012). This species has become a national priority in Indonesia for increasing its population by the Ministy of Forestry and Environment (H. Bashari in litt. 2016). Populations occur in several protected areas, the most important being Rawa Aopa Watumohai (55 individuals in 2011 [Waugh 2013]) and Caraente National Parks (on Sulawesi) which supports up to 100 individuals (Nandika 2006), Suaka Margasatwa Nature Reserve on Pulau Moyo, Komodo National Park and two national parks on Sumba: Manupeu-Tanadaru and Laiwangi-Wanggameti. The declared Nini Konis Santana National Park in Timor holds an estimated 100 birds (Trainor et al. undated). In Rawa Aopa Watumohai nests have been protected from predators by removing overhanging vegetation and fitting plastic collars around the trunks of nesting trees (Waugh 2013). Moratoria on international trade are in place, although it is likely that a large proportion of the trade is domestic. Several cockatoo subpopulations have increased on Sumba between 1992 and 2002, due to conservation efforts (including local education, eco-tourism and law enforcement), although densities remained below those typical of other cockatoo species (Cahill et al. 2006). Capture for trade has apparently decreased dramatically on Sumba thanks to a variety of awareness-raising activities and community protection measures (D. Mulyawati in litt. 2012). 

Following surveys in 2008 and 2009, the Indonesian Parrot Project and Konservasi Kakatua Indonesia have initiated meetings with community leaders and villagers on Masakambing and Masalembu, as well as the local military and police, to raise awareness and garner support for the species's conservation (Metz et al. 2009). A conservation-awareness-pride programme has also begun to engage both adults and school children of the Masalembu Archipelago (Metz et al. 2009, Nandika et al. 2009) and in south-east Sulawesi (Anon. 2012). A 'village regulation' was drafted to make it illegal to trap, own or transport the species, and to initiate measures to reduce habitat destruction and employ a former village head to monitor and protect nests and study the species (Nandika et al. 2009). Similar community-based regulations have been put in place by the Moronone community in Rawa Aopa Watumohai NP, where four village members have been hired as Forest Wardens (Anon. 2012). The wardens protect the species against poachers and carry out monitoring activities (Waugh 2013). The species's pest status may be tackled by the planting of crops to compensate for losses and to act as a 'sacrifice crop', for instance sunflower fields are used to attract the species away from other crops (Waugh 2013). Mangrove restoration is also being used to increase available nesting habitat (Waugh 2013). A repeated census of the abbotti population is planned, along with studies into its life history and ecology (Metz et al. 2009).

Conservation and Research Actions Proposed
Conduct further surveys (including Roti but also further surveys on Alor and Pantar) to identify the most appropriate areas for conservation action and to periodically monitor key populations by repeating surveys conducted 8-10 years ago. Provide support for relevant protected areas and conservation initiatives within its range and protect nest trees where possible. Strengthen protection of the Poronumbu Forest, Sumba, by declaring it a Nature Reserve (Nandika and Agustina 2012). Strengthen control, law enforcement and monitoring of trade and establish greater management of captive populations. Improve law enforcement in designated protected areas and other key areas for trade including ports, markets, etc. Promote widespread community-based conservation initiatives. For instance on Pasoso Island, Central Sulawesi, work to protect the species should involve engaging with the five families that live on the island and introduce community engagement programmes for children and adults on several of the other islands where the species is found (Nandika and Agustina 2012). Recommendations made specifically for the protection of the species in Komodo National Park were to conduct annual monitoring, maintain regular patrols, raise awareness in local communities and study human activities and impacts within the park (Imansyah et al. 2005, Benstead 2006). Conduct ecological research to clarify options for its management and conservation. Additional targets should be to study the abundance and distribution of nest holes and water sources. Providing artificial water sources near nest locations, i.e water ponds, is essential for the species on Komodo Island and protecting nests from juvenile Komodo Dragons on Komodo may also be necessary (Nandika and Agustina 2012).


33-35 cm. Medium-sized, white cockatoo. All-white, but for long, forward-curling yellow crest (more orange in race citrinocristata), yellow ear-coverts and yellow under-surfaces to wings and tail. Black bill, bluish, bare eye-ring and grey feet. Similar spp. Sulphur-crested Cockatoo C. galerita is much larger and has white skin around eye. Voice Loud and very raucous. Often gives single harsh screech but also sweeter whistles and squeaky notes.


Text account compilers
Ashpole, J, Westrip, J., Martin, R., Benstead, P., Calvert, R., Derhé, M., Symes, A., Butchart, S., Taylor, J., Tobias, J., Bird, J.

Kelly, D., Verbelen, F., Imansyah, J., Trainor, C., Bashari, B., Mulyawati, D., Lehmberg, T.

Recommended citation
BirdLife International (2020) Species factsheet: Cacatua sulphurea. Downloaded from on 15/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from on 15/08/2020.