Palm cockatoos mainly eat leaf buds, seeds, and fruits. They sometimes also eat insects and their larvae. They forage primarily in the forest canopy, but may also forage on the forest floor for fallen fruits and seeds. They crush seeds and hard fruits with their sharp, strong mandibles.
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; fruit
Primary Diet: herbivore (Frugivore , Granivore )
Confirmed reports of predation on palm cockatoos was not found. However, common brushtail possums steal eggs from glossy black cockatoo nests, a close relative of palm cockatoos. Egg predation was found to greatly reduce the population size of the glossy black cockatoos. Arboreal snakes are also potential nest predators. Large birds of prey may take adults.
Competition between cockatoo species for nesting sites is high, and may result in egg or nestling death when cockatoo individuals fight over a nest.
Palm cockatoos are the largest of all parrots, ranging from 49 to 68 cm in height. They weigh 500 to 1100 g, with females ranging from 500 to 950 g and males ranging from 540 to 1100 g. Wing length is around 35.1 cm, tail length 23.8 cm, bill length 9.1 cm, and tarsus length averages 3.5 cm.
Palm cockatoos are almost all black with a 15 cm erectile crest on their head. Their beaks never close completely, always revealing a bit of their black-tipped red tongues. This partly open mouth makes it easier for the birds to hold nuts in their mouth and crack them at the same time. Their strong mandibles are used for cracking nuts and are larger in males than in females. Their legs are grey/black with few feathers on their thighs and their red facial markings are their most distinguished characteristic. Their cheek skin changes color based on their health or level of stress so when highly stressed the skin will change color to a pink/beige, while when highly excited the skin changes to yellow. In young birds, the underfeathers are lined with a pale yellow and in very young birds (under 18 months old), the tip of the bill and the eye ring are white.
Range mass: 500 to 1100 g.
Range length: 49 to 68 cm.
Range wingspan: 70 to 100 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
The lifespan of wild palm cockatoos is not well known. Other cockatoo species live from 40 to 60 years in the wild. Captive cockatoos may live to more than 100 years old.
Average lifespan
Status: captivity: 56.3 years.
Palm cockatoos are found in rainforests, including gallery forests, forest edges, monsoon woodlands, eucalypt and paperbark woodlands, partly cleared areas, and dense savannas. They choose large trees for nesting and roosting. During the day they roost near food or water sources and at night roost in or near a nest tree.
Range elevation: 1300 (high) m.
Average elevation: below 750 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Other Habitat Features: riparian
Palm cockatoos are found in the Australasian region, including New Guinea, the Cape York Peninsula (Northern Australia), Aru Islands, West Irian, Misool Isle (Western Papuan Islands) and other islands. There are three subspecies, P. a. atterimus, found in the Misool Isles, Aru Islands, and Northern Australia, P. a. goliath, the largest of the subspecies, found in Western Irian and the Papuan Islands, and finally P. a. stenolopus, in New Guinea and Western Irian.
Biogeographic Regions: australian (Native )
Palm cockatoos aid in the dispersal of seeds for many fruit-bearing trees. Many plant species have evolved methods to attract large, frugivorous birds to further enhance the probability of seed dispersal.
Ecosystem Impact: disperses seeds
Palm cockatoos are sometimes kept as pets or in zoos because people enjoy the intelligence, sociality, and vocal dexterity of parrots. Unfortunately, trade in cockatoos sometimes harms wild populations.
Positive Impacts: pet trade ; ecotourism ; research and education
Because palm cockatoos take quickly to accepting food from humans, they are known to raid bird feeders. They may destroy wood decks and the paneling of houses.
Negative Impacts: household pest
Palm cockatoos are considered near threatened or low risk due to the destruction of habitat with logging and seasonal fires. Additionally, in the 1970s, keeping palm cockatoos as pets became quite popular, and since then they have been the object of hunting for the aviary trade with the most popular tactic of capture involving arrows covered in sticky resin. There are now laws that prohibit the export of any palm cockatoo without a permit. Unfortunately, many are still illegally exported and sold as pets, and they do not survive well in captivity.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: appendix i
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Palm cockatoos are one of the loudest parrot species, making loud whistling calls. The most common call heard is the contact call which is a disyllabic whistle. When they are alarmed they produce a sharp, harsh screech. Other calls include grunts, mournful/wailing cries, whistles, and screeches. Another way they communicate is by stomping noisily on a perch, using sticks or nuts to drum against the tree, sometimes up to 200 times. This is usually used to advertise territorial boundaries. Their cheeks will change color with mood, stress, and health. They also use their erectile crest to communicate mood.
Communication Channels: visual ; acoustic
Other Communication Modes: mimicry
Perception Channels: visual ; tactile ; acoustic ; chemical
Probosciger aterrimus, is derived from the Greek words "proboscis" which means nose and "gero" which means to carry. The specific name is from the Latin "aterrimus," meaning very black.
During mating the male and female approach each other with wings extended. Before mating the male makes loud whistles and bows several times during which the skin on the face will usually become a deep red. Sometimes the male will also bang a stick against a tree while calling out, as a territorial gesture near the nesting sight. Palm cockatoos are monogamous and stay together for life.
Mating System: monogamous
The mating season varies with local climate, but is usually from August to January. Palm cockatoos cannot excavate their own nesting cavities. Instead they use previously hollowed cavities in large trees, such as palms. Their nesting holes tend to be about 1 m in depth and 25 to 60 cm in diameter are are lined with a pile of broken twigs at the bottom, upon which the egg rests. The same site is often used year after year.
Palm cockatoos lay one egg per clutch, which is incubated for 30 to 33 days. The newly hatched young are naked and helpless. They take 100 to 110 days to fledge, the longest period to fledging of any parrot species.
After leaving the nest, the young bird is dependent on the parents for at least another 6 weeks because of its inability to fly. After this, the young bird will be independent, but will stay relatively close to the parents until the next breeding season, whereupon the parents evict the previous year's young from their territory. Young birds are estimated to reach sexual maturity at 7 to 8 years old.
Breeding interval: Palm cockatoos breed once yearly.
Breeding season: The breeding season usually occurs between the months of August and January, but varies with local climate.
Average eggs per season: 1.
Range time to hatching: 30 to 35 days.
Range fledging age: 100 to 110 days.
Range time to independence: 142 to 152 days.
Range age at sexual or reproductive maturity (female): 7 to 8 years.
Range age at sexual or reproductive maturity (male): 7 to 8 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Although both parents participate in incubation, females incubate the egg more than males and males spend more of their time foraging for food. After hatching, chicks are brooded mostly by females. Males also brood the young, but are mainly responsible for finding food. After the chick leaves the nest, both parents provide food and protection for it until it is fully independent.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents
The palm cockatoo (Probosciger aterrimus), also known as the goliath cockatoo or great black cockatoo, is a large smoky-grey or black parrot of the cockatoo family native to New Guinea, Aru Islands, and Cape York Peninsula.[3] It has a very large black beak and prominent red cheek patches.[4]
The palm cockatoo was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the parrots in the genus Psittacus and coined the binomial name Psittacus aterrimus.[5] Gmelin based his description on the "black cockatoo" that had been described and illustrated in 1764 by the English naturalist George Edwards.[6] Joan Gideon Loten had provided Edwards with a drawing of the bird by the Sri Lankan artist Pieter Cornelis de Bevere.[7] The original drawing by de Bere is in the collection of the Natural History Museum, London.[8] The palm cockatoo is now the only species placed in the genus Probosciger that was introduced by Heinrich Kuhl in 1820.[9][3] The genus name combines the Latin proboscis meaning "snout" with -ger meaning "carrying". The specific epithet aterrimus is Modern Latin meaning "very black".[10] The accepted type locality is the Aru Islands,[11][12] rather than "northern Australia".[13]
The palm cockatoo is a member of the white cockatoo subfamily Cacatuinae.[14] Earlier limited genetic studies found it to be the earliest offshoot from the ancestors of what have become the cockatoo family.[15]
"Palm cockatoo" has been designated the official name by the International Ornithological Committee (IOC).[3] The species was named the "Goliath Aratoo" in Wood's Natural History (1862). It is also sometimes given the misnomer "black macaw" in aviculture – the macaws are unrelated New World parrots. Confusingly, this name was also used by early naturalists and Brazilian natives to refer to the dark blue hyacinth macaw.
Four subspecies are recognized.[3]
A 2007 genetic study found little support for the above division into subspecies.[16]
The palm cockatoo is 55 to 60 cm (22 to 24 in) in length and weighs 910–1,200 g (2.01–2.65 lb).[17] It may be the largest cockatoo species and largest parrot in Australia, although large races of yellow-tailed black cockatoos and sulphur-crested cockatoos broadly overlap in size. It is a distinctive bird with a large crest and has one of the largest bills of any parrot (only the hyacinth macaw's is larger). This powerful bill enables palm cockatoos not only to eat very hard nuts and seeds, but also enables males to break off thick (about 1 in) sticks from live trees to use for a drumming display.[18] The male has a larger beak than the female.[17] The beak is unusual, as the lower and upper mandibles do not meet for much of its length, allowing the tongue to hold a nut against the top mandible while the lower mandible works to open it. The palm cockatoo also has a distinctive red cheek patch that changes colour when the bird is alarmed or excited.
The races P. a. goliath and P. a. stenolophus are larger than the nominate subspecies. The race stenolophus also has narrower crest feathers.[12]
The vocalizations of palm cockatoos are similar to those of most wild parrots, but they have also been shown to produce a variety of additional syllables in display and exchange with neighbouring individuals. These additional syllables are mainly produced by males and are often combined to form long, complex sequences. In a population in the Iron Range, 30 different syllables were distinguished.[19] The palm cockatoos from the east have different call types from the ones from other areas, due to their long term isolation.[20]
The palm cockatoo is found in rainforests and woodlands of New Guinea and Cape York Peninsula, Queensland, Australia. It can still be found near Sorong, West Papua, Indonesia, where it is sometimes seen in trees along the roads.[21]
It has a unique territorial display where the bird (typically the male) drums with a large (i.e. up to 2.5 cm diameter, 15 cm long) stick or seed pod against a dead bough or tree, creating a loud noise that can be heard up to 100 m away.[22] After drumming, the male occasionally strips the drum tool into small pieces to line the nest.[23] Although this drumming behaviour was discovered over three decades ago (in 1984 by G.A. Wood), the reason why palm cockatoos drum is still a mystery. One reason could be that females can assess the durability of the nesting hollow by the resonance of the drumming. Another possibility could be that males drum to mark their territory against other males. The palm cockatoo is an unusual bird, being an ancient species and one of the few bird species known to use tools.[21]
This species normally does not appear in large numbers. They are not known to flock feed like many of the cockatoo species. Usually only one to six individuals are observed feeding together at one time. As with other large birds, both parents care for young, so seeing a breeding pair is not unusual. If these birds do congregate, it will usually happen in open woodland just after sunrise or along the rainforest edge before returning to individual roosts for the night.[24]
Palm cockatoos only lay one egg every second year and have one of the lowest breeding success rates reported for any species of parrot.[25] Offsetting this is their very long lifespan. A male commenced breeding at 29 in Taronga Zoo in Sydney, and a female at the London Zoo was 40 when she laid her first egg in 1966. Breeding takes place inside tree hollows that look like standing pipes. Fires play an important role in the destruction and creation of nest hollows. Fires allow the colonisation of microorganisms and termites, which enter the tree and start hollowing out the inside. Cyclones are important in the final stage of nest hollow development.
Anecdotal evidence indicates a palm cockatoo reaching 80 or 90 years of age in an Australian zoo,[25] although the oldest confirmed individual was aged 56 in London Zoo in 2000.[26] Although longevity of captive birds is known, the lifespan of palm cockatoos that live in the wild is still unknown.
The palm cockatoo often feeds during the early hours of the day on a diet that consists mostly of wild growing pandanus palm fruit and nuts from the kanari tree. They have also been seen eating fruit from Darwin stringy bark Eucalyptus tetradonta and nonda tree, as well as seeds from the cocky apple tree, beach almond, and black bean tree.[24]
The palm cockatoo is still relatively common in Cape York, but is threatened there by habitat destruction, particularly due to bauxite mining around Weipa and altered fire regimens elsewhere. Palm cockatoos are hunted in New Guinea. The palm cockatoo is currently evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix I of CITES. In Australia, palm cockatoos were relisted from Near Threatened to Vulnerable on 31 October 2015 (EPBC Act List of Threatened Fauna).
This species is in high demand for the pet trade due to its unusual appearance. In early captive situations, pet owners would either feed dog kibble or generic bird seed mixture, while zoos would give them "monkey biscuits". As their nutritional needs became more apparent over the years, owners have shifted to specially formulated "manufactured diet" pellets along with a wide variety of treats like peanuts, pecans, Brazil nuts, pine nuts, sunflower seeds, oranges, apples, grapes, pomegranate, bananas, sweet potatoes, carrots, beets, broccoli, and kale. Many zoos still give them monkey biscuits to broaden their diet.[27]
The palm cockatoo (Probosciger aterrimus), also known as the goliath cockatoo or great black cockatoo, is a large smoky-grey or black parrot of the cockatoo family native to New Guinea, Aru Islands, and Cape York Peninsula. It has a very large black beak and prominent red cheek patches.
