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.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Distribution and populationCacatua sulphurea
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.
is endemic to Timor-Leste
, 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 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 (but considerably smaller) populations are on Komodo (c.500 individuals), Sulawesi and Buton (combined remaining population of perhaps 200 individuals but almost extirpated from Buton by 2009; Anon. 2012), Sumbawa (107 birds in a recent census, Anon. 2013), Moyo, Timor-Leste (Trainor et al.
undated), Alor (a loose flock comprising c. 18 birds was observed in 2009) 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. It is likely extirpated from Lombok (F. Verbelen in litt.
Based on recent surveys within various parts of the species's range, C. Trainor (in litt
. 2007) has estimated the global population at fewer than 7,000 individuals: 3,200-5,000 on Sumba (although perhaps as few as 562 in 2012, Burung Indonesia in prep), 500 on Komodo, 200-300 on Timor Leste, 200-300 on Sulawesi, 20-50 on West Timor, 40-70 on Flores, 50-100 on Sumbawa, 100 on Rinca and c.700 other birds in total. It is best placed in the band 2,500-9,999 individuals, equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 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 2000-2005.Ecology
It 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 does not require large areas of forest (D. Mulyawati in litt.
2012). 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
sp (Nandika et al.
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. 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. 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 and Research Actions Underway
CITES Appendix I (2005). A cooperative recovery plan has been developed and adopted, with an update being prepared in 2012 (D. Mulyawati in litt.
2012). Populations occur in several protected areas, the most important being Rawa Aopa Watumohai 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). 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 apaprently decreased dramatically on Sumba thanks to a variety of awareness-raising activities and community protection measures (D. Mulyawati in litt.
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 species's pest status may be tackled by the planting of crops to compensate for losses and to act as a 'sacrifice crop'. 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 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. 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 Yellow-crested Cockatoo on Komodo Island.
Related state of the world's birds case studies
Agista, D.; Rubyanto, D. 2001. Telaah Awal Status, Penyebaran dan Populasi Kakatua-kecil Jambul-kuning (Cacatua sulphurea parvula) di Taman Nasional Komodo Nusa Tenggara Timur..
Anon. 2008. World's rarest Cockatoo rediscovered in Indonesia. Available at: #http://www.prweb.com/releases/rare/cockatoo/prweb1506694.htm#.
Anon. 2012. Yellow-crested Cockatoo conservation in Sulawesi and Masakambing, Indonesia. Cyanopsitta 100: 28-30.
Anon. 2013. Yellow-crested cockatoo population in critical condition. Available at: http://www.thejakartapost.com/news/2013/03/18/yellow-crested-cockatoo-population-critical-condition.html. (Accessed: 09/10/2013).
Benstead, P. 2006. OBC in action: conservation fund: Survey of distribution and status of nests of Yellow-crested Cockatoo Cacatua sulphurea parvula in Komodo National Park. BirdingASIA: 7-8.
BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.
Cahill, A.J.; Walker, J.S.; Marsden, S.J. 2006. Recovery within a population of the critically-endangered Citron-crested Cockatoo Cacatua sulphurea citrinocristata in Indonesia after 10 years of international trade control. Oryx 40: 161-167.
Imansyah, M.J.; Anggoro, D. G.; Yangpatra, N.; Hidayat, A.; Benu, Y.J. 2005. Sebaran dan karakteristik pohon sarang Kakatua jambul kuning (Cacatua sulphurea parvula) di Pulau Komodo, Taman Nasional Komodo.
Imansyah. 2008. Preliminary population estimates of the critically endangered Yellow-crested Cockatoo Cacatua sulphurea on Komodo Island, Indonesia.
Johnstone, R. E.; Jepson, P. 1996. The birds of Roti Island, Nusa Tenggara, Indonesia. Western Australian Naturalist 21: 23-35.
Nandika, D. 2006. Recent observations of the critically endangered Sulphurea subspecies of Yellow-crested Cockatoo: Rawa Aopa Watumohai National Park SE Sulawesi, Indonesia. PsittaScene 18: 10-11.
Trainor, C. R. 2005. Birds of Tapuafa peninsula, Roti island, Lesser Sundas, Indonesia. Forktail 21: 121–131.
Trainor, C. R., Imanuddin, Aldy, F., Verbelen, P. and Walker, J. S. 2009. The birds of Wetar, Banda Sea: one of Indonesia's forgotten islands. BirdingASIA 12: 78-93.
Walker, J.S.; Cahill, A.J.; Marsden, S.J. 2005. Factors influencing nest-site occupancy and low reproductive output in the critically endangered Yellow-crested Cockatoo Cacatua sulphurea on Sumba, Indonesia. Bird Conservation International 15: 347-359.
Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).
Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.
View photos and videos, and hear sounds of this species from the Internet Bird Collection
Text account compilers
Benstead, P., Bird, J., Butchart, S., Calvert, R., Derh, M., Symes, A., Taylor, J. & Tobias, J.
Imansyah, J., Kelly, D., Trainor, C., Verbelen, F. & Mulyawati, D.
BirdLife International (2013) Species factsheet: Cacatua sulphurea. Downloaded from
http://www.birdlife.org on 05/12/2013.
Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 05/12/2013.
This information is based upon, and updates, the information published in BirdLife International (2000)
Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004)
Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.
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Additional resources for this species