Species Fact Profile: Palm Cockatoo (Probosciger aterrimus)

Palm Cockatoo

Probosciger aterrimus (Gmelin, 1788)

Range: New Guinea, Northern Australia (Cape York Peninsula), Aru Islands, and other islands in the region

Habitat: Lowland rainforest (up to 1350 meters elevation), as well as densely wooded savannah.  Their main habitat requirement is an availability of large trees for nesting

Diet: Leaf Buds, Seeds, Fruits.  Occasional insects

Social Grouping: Pairs, Small Flocks (up to 6 birds)

Reproduction: Breeding season varies by location, but usually happens August through January.  Monogamous for life.  Display for one another with extended wings, bowing, and whistling.  Nest in cavities in large trees, lined with broken twigs.  A single egg is incubated by both parents for 30-33 days.  Chicks fledge at 100-110 days (the longest period of any parrot), then is dependent on its parents for an additional 6 weeks.  Sexually mature at 7-8 years old

Lifespan: Estimated 80 Years +, Documented 60 Years

Conservation Status: IUCN Least Concern, CITES Appendix I

• Body length up to 60 centimeters (including the tail) and weigh up to 4.8 kilograms, with females being a quarter to a third larger than the males.  The largest horseshoe crabs are found in the central portion of the range, with the extreme northern and southern crabs being smaller
• Largest of the cockatoos and largest parrot in Australia, measuring 49-68 centimeters long and weighing 500 to 1100 grams, with males being slightly larger on average than the females
• Plumage is black, with a 15 centimeter tall crest of erectile feathers on top of the head.  The legs are greyish-black, as is the beak.  The only patch of color is red facial marking; this patch of skin will change color depending on the health and stress levels of the animal, ranging from pink to yellow.  Sexes look alike; juveniles differ from adults in having pale yellow under-feathers, a white tip to the beak, and a white ring around the eye
• The large, powerful beak never fully closes, leaving a red, black-tipped tongue constantly exposed.  This allows the bird to hold a nut against the top mandible with its tongue while the lower mandible works to open it.  Males have larger beaks than females.  Second largest bill of any parrot (only that of the hyacinth macaw is larger)
• They will maintain territories, beating on trees with sticks (up to 15 centimeters long and 2.5 centimeters in diameter) or nuts like drums to advertise their occupancy of a territory (sometimes beating as many as 200 times).  It is one of the few bird species known to use tool
• Highly vocal, one of the loudest parents.  The most common call is a contact call, a disyllabic whistle.  They can also make a harsh screech when alarmed, as well as grunts and wails.  Distinct dialects have been reported across the species range
• Primarily feed in the canopy, but may come to the forest floor to feed on fallen fruit.  They are possibly important seed dispersers for some species
• They have been observed eating soil from clay licks, possibly in order to bind with toxic compounds in some of the plants that they eat
• Three to four recognized subspecies, differing slightly in size, crest shape, and color.  The nominate. a. aterrimus, is from northern Australia and nearby islands.  P. a. goliath is the largest, from west Irian and the Papuan islands, and P. a. stenolopus is from New Guinea.  Some authorities additionally recognize P. a. macgillivrayi.  Some authorities suggest that only P. a. goliath is a valid subspecies. 
• Primary threat is the loss of habitat due to logging and fire (though natural fires are an important feature for developing tree cavities), which especially impacts the availability of the large trees needed for nesting.  They can be tolerant of some habitat disturbance and the presence of humans, even visiting houses and taking food from people
• Additional threat is illegal capture of birds for sale on the pet trade.  Most palm cockatoos in the US are descended from birds taken from a large confiscation by USFWS of approximately 100 birds in 1983.  Birds that the government did not place in zoos were sold to the private sector, helping to establish this species in the US