| Palm Cockatoo | |
|---|---|
| At Melaka Zoo, Malaysia | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Psittaciformes |
| Family: | Cacatuidae |
| Subfamily: | Microglossinae |
| Genus: | Probosciger Kuhl, 1820 |
| Species: | P. aterrimus |
| Binomial name | |
| Probosciger aterrimus Gmelin, 1788 |
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| subspecies | |
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P. a. aterrimus |
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| Australian Palm Cockatoo range (in red) | |
The Palm Cockatoo (Probosciger aterrimus), also known as the Goliath Cockatoo, is a large smoky-grey or black parrot of the cockatoo family. It is the only member in subfamily Microglossinae and the only member of the monotypic genus, Probosciger. Its unique position within the cockatoo family has been confirmed by molecular studies.
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The Palm Cockatoo was originally described by German naturalist Gmelin in 1788. Its specific name aterrimus is the Latin superlative adjective for ater "black", hence "very black" or "blackest". It is the earliest offshoot from the ancestors of what have become the cockatoo family.[1]
The Palm Cockatoo is 55–60 cm (22–24 in) in length and weighs 910–1,200 g.[2] 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 parrots (only the Hyacinth Macaw's is larger). This powerful bill enables Palm Cockatoos to not only eat very hard nuts and seeds, but it also enables males to break off thick (~1") sticks from live trees to use for a drumming display (Wood 1984). The bill 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 Palm Cockatoo is distributed in rainforests and woodlands of New Guinea island in Indonesia and Papua New Guinea, and northern Queensland, Australia. It still can be found wild and free on the branches of the trees along side the road in Sorong, West Papua, Indonesia.[3]
The Palm Cockatoo has a large and complex vocal repertoire, including many whistles and even a "hello" call that sounds surprisingly human-like.
There are distinct dialects throughout the species' range. It has a unique territorial display where the bird (typically the male) drums with a large (i.e. up to 1" 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.[4] After drumming, the male occasionally strips the drum-tool into small pieces to line the nest.. Although this drumming behaviour was discovered over two 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. Palm Cockatoo is an unusual bird, being that it is an ancient species and one of the few bird species known to use tools.[3]
Palm Cockatoos only lay one egg every second year and have one of the lowest breeding success rates reported for any species of parrot.[5] Off-setting this is their very long life-span. A male commenced breeding at age 29 in Taronga Zoo in Sydney, and a female at the London Zoo was 40 when she laid her first egg in 1966. There is anecdotal evidence of a Palm Cockatoo reaching 80 or 90 years of age in an Australian zoo,[5] although the oldest confirmed individual was aged 56 in London Zoo in 2000.[6] Although longevity of captive birds is known, it is still unknown how long palm cockatoos live in the wild. 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.
They have a very specific and restricted diet, making them expensive to buy and expensive to own and maintain.
The Palm Cockatoo is still relatively common in Cape York, but is threatened there by habitat loss, particularly bauxite mining around Weipa and altered fire regimes elsewhere. Palm Cockatoos are hunted in New Guinea. This species is in high demand for the pet trade due to its unusual appearance. 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.
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