Palm Cockatoo

## Description

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.

## Appearance

The Palm or Goliath cockatoo is a large black or smoky-gray parrot from the cockatoo family. It has a distinctive appearance, having a large crest and one of the biggest beaks of any parrot, a beak unusual in itself, as the upper and lower mandibles do not meet along much of the length, which allows the bird’s tongue to hold a nut in place against its top mandible while its lower mandible does the work to open it. Between the eyes and the beak there is a patch of bare skin, red in color. There is also a distinctive red patch on the cheek that changes color if the bird is excited or alarmed. In young birds, their underfeathers are lined with pale yellow and in birds under the age of 18 months, the tip of the beak and the ring around the eye are white.

## Distribution

The Palm cockatoo inhabits New Guinea and the northern Queensland’s Cape York Peninsula, and also an area near Sorong in West Papua. They occur in rainforests, such as gallery forests, forest edges, eucalypt and paperbark woodlands, monsoon woodlands, dense savannas and partly cleared areas. They choose big trees for roosting and nesting.

## Behavior

Palm cockatoos are found alone, in pairs, or in larger groups. Sometimes they stay quite close by their nesting sites, but they can travel a long way to search for food or water. A few trees for nesting sites are included within their territory. They visit these sites during the year for a variety of reasons, increasing the visiting frequency in the breeding season. Often they feed in big groups, one "sentinel" bird watching out for predators. Should a predator or another threat appear, the “sentinel” makes an alarm cry to warn the flock. These cockatoos are highly social birds, gathering early in the day in groups in their favorite locations to spend time interacting and preening. They roost during the day near sources of food or water and at night they roost in or nearby a nest tree. During the rain they can be found, as if taking a shower, hanging upside down, stretching out their wings and tails.

## Diet

Palm cockatoos eat mainly leaf buds, fruits, and seeds. They also sometimes consume insects and their larvae.

## Reproduction

Palm cockatoos are monogamous and pairs stay together for life. Breeding usually takes place from August to January, but can vary with the local climate. These birds are not able to excavate nesting cavities, so they make use of cavities that have been hollowed out in big trees, such as palms. Year after year the same site is often used. Palm cockatoos lay a single egg per clutch, and incubation is carried out by both parents for between 30 and 33 days. Chicks fledge in 100 to 110 days, the longest fledgling period of any parrot. Once it has left the nest, the fledgling is dependent on its parents for at least 6 more weeks, due to its inability to fly. Then the young bird will have reached independence, but will remain relatively close to its parents until the next mating season. Young birds are sexually maturity at the age of 7 to 8.

## Population

### Population threats

The Palm cockatoo is under threat by habitat loss through logging and seasonal fires, which each year destroy their nest trees in significant numbers. In New Guinea they are hunted, being in high demand for sale in the pet trade because of their unusual appearance.

### Population number

According to the IUCN Red List, the global population size of Palm cockatoo has not been quantified, but the species is still recorded relatively commonly and appears to have a large overall population. P. a. macgillivrayi, one of the four recognized subspecies, is believed to have a stable population of 3,000 individuals. Palm cockatoos are classified as Least Concern (LC) on the list of threatened species but their numbers are decreasing.

### Ecological niche

Palm cockatoos play a part in seed dispersal for the many fruit-bearing trees of which they eat the fruit.

## Domestication

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.

## Fun Facts for Kids

The Palm cockatoo has the largest bill of any parrot except for the hyacinth macaw. This powerful bill means that palm cockatoos can eat very hard seeds and nuts that are difficult for other species to deal with.
The bare red patch on the Palm cockatoo’s cheek can change color, depending on their health or stress level. When highly stressed the patch will change to a pink/beige, and when highly excited it changes to yellow. The birds can reveal or hide the cheek patch by changing the position of their facial feathers.
Palm cockatoos make loud whistling calls and are amongst the loudest of the parrot species. The most common call is the contact call, a whistle of two syllables. When alarmed, they make a sharp, harsh screech. They also make grunts, mournful/wailing cries, screeches, whistles, and other noises.
Palm cockatoos can also communicate by stomping noisily on their perch, drumming against a tree with sticks or nuts, as many as 200 times, usually for the purpose of advertising territorial boundaries. Their erectile crest also communicates mood.
This bird’s nesting behavior is unique for cockatoos because they construct a platform made of twigs within its nest cavity.