Palm Cockatoos
 
Physical Characteristics
The Cockatoo is a large (49 cm to 68 cm in length, 500-1100 grams in weight) predominately black bird with a spectacular backward curving erectile crest. The massive upper mandible is considerably larger in males than in females. The black tipped red tongue remains visible through much of the length of the unique bill, which meets only at the tip. The Cockatoo has powder down, which dulls their glossy beak and adds a gray color to their black plumage. The legs are gray-black and have somewhat sparsely feathered thighs. Their red, naked facial markings are their most distinctive characteristic. The color of the facial patches can range from off white to burgundy and its intensity may vary according to the individual's stress level or general health.
Palm Cockatoos emit a wide variety of vocalizations, displays and other behaviors that enable them to maintain contact and communicate effectively with one another in their heavily forested habitat. These vocalizations include a variety of cries, whistles, grunts, and screeches. They will also stomp noisily on a perch and use a stick or nut to drum loudly on a hollow log.
Distribution
Palm Cockatoos are native to the Cape York Peninsula of northern Australia, the Aru Islands, Papua New Guinea, and other surrounding smaller islands.
Habitat
The Cockatoo is the only cockatoo species adapted to tropical rain forest habitat. The other members of the cockatoo family prefer drier habitats. Palm Cockatoos require large trees for nesting and roosting. Daytime roosts are usually near their current food source and a water source. At night they prefer to roost in or near their nest tree.
Food
Palm Cockatoos have been observed feeding on seeds, nuts, fruits, berries, and leaf buds. They feed primarily in trees, but also feed on fallen seeds and fruits on the ground. On the Cape York Peninsula, they have been observed eating the seeds of the kanari and black bean trees, and the fruits of the nonda tree and Pandanus palms. Palm Cockatoos have also been observed eating seeds that have passed through cassowaries, which may make them easier to open.
Reproduction
Palm Cockatoos are unable to excavate nesting hollows themselves and must utilize existing cavities in large trees. Their large size and the length of their tails require Palm Cockatoos to find particularly wide hollows in mature trees. Most suitable nest trees are more than 100 years old and competition for prime hollows with other birds, marsupials, reptiles and even bees can be fierce. Palm Cockatoos create nesting material from vegetation such as eucalyptus, bamboo, acacia, and willow. They will splinter soft branches and carry the pieces into the nest.
Pairs of Palm Cockatoos maintain territories with several potential nesting locations. Visits to these nesting trees increase during the breeding season. Their breeding season in the wild will vary with the climate. It usually occurs during the months of August through January. The breeding sites tend to be high up in the trees, with a typical cavity depth of 1 meter and a diameter of 25 to 60 cm. A pair will usually use a suitable nest site year after year. During courtship, the male Cockatoo will approach the female with his wings partially extended. His head is upright while his crest feathers are fully erect and he will bow several times before mounting. Vocalizations consisting of loud whistles are emitted by the male throughout courtship.
Palm Cockatoos lay only one egg per clutch. Incubation is done by both parents, and lasts approximately 30-33 days. The female does most of the incubating and may be fed by the male while on the nest during the 30-33 day incubation period. After pipping, it usually takes three to four days for the chick to hatch. Upon hatching, the chick is naked without any down feathers. Until the newly hatched chick is able to maintain its own body temperature it will be brooded by the female while the male provides food for both mate and chick.
When the chick is fully feathered both parents are free to share foraging duties. The chick does not emerge from the nest until it reaches 100 to 110 days of age. This is the longest nesting period known for any parrot species. After leaving the nest, the chick is not yet competent to fly, and is fed by both parents for an additional six weeks. The juvenile will remain with its parents until driven off at the beginning of the next breeding season. It is estimated that Palm Cockatoos reach sexual maturity at about seven to eight years of age.
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