Black Cockatoos; wailing spirits of the land

No, I haven't really gone all mystical since last year, but there is something truly thrilling about a flight of massive black-cockatoos rowing easily across the sky, their creaking wailing calls drifting down as they pass over. This is a uniquely Australian experience, as the five species all evolved here and are found nowhere else.

Yellow-tailed Black-Cockatoos Zanda funerea, part of a large flock flying over Lower Glenelg NP,
far western Victoria, under a leaden sky.

Overall there are 21 species of cockatoo that together comprise the family Cacatuidae. The only ones found outside of Australia are seven of the 11 species of the genus Cacatua, which live in New Guinea and nearby islands scattered as far as Sulawesi and the Philippines. Although the massive Palm Cockatoo Probosciger aterrimus is also black, it is much more closely related to the white and pink cockatoos.

Red-tailed Black-Cockatoo Calyptorhynchus banksii, Nitimiluk NP, Northern Territory.
Coming in to land, it shows the typical black-cockatoo characters of long rounded
wings and long tail, massive bill and overall dark plumage with coloured tail panels.
This one is moulting, currently regrowing the outside left tail feather.

Red-tailed Black-Cockatoo landing, Bourke, New South Wales, and giving
a slightly better view of the lovely tail panels.

Yellow-tailed Black-Cockatoo, Murramarang NP, south coast New South Wales,
cracking banksia cones to get at the nutritious seeds - an accomplishment that would be
fatal to our teeth! This shows better the huge powerful bill and also the typically
zygodactylous feet, though this is not a structure unique to the cockies.
The four toes are opposed with the outside two pointing backwards and the middle two
facing forwards. This is an excellent arrangement for both grasping food and for
clambering in trees. (This bird is a male, with dark bill and reddish eye-ring.)

We have now met the two genera, Zanda (with yellow or white highlights) and Calyptorhynchus (with red or orange panels). For most of their taxonomic history they have all been included in Calyptorhynchus, a name applied by the French zoologist Anselme Desmarest in 1826. It means 'covered bill' (ie the base of it, by feathers), and while true it is certainly not unique. In 1913 the somewhat erratic but highly productive Gregory Mathews, a wealthy Australian working from England, separated out the 'yellow and white' black-cockatoos and called them Zanda. Characteristically he didn't see a need to explain the name, and it might have been inspired by an Indigenous name (though probably not, as he also used it as a subspecies name for several unrelated birds) or he might simply have made it up - he had form. Also typically it didn't take on, until within the past decade when based on plumage characters (coloured bars and speckles on the 'red' females, but not the 'whites and yellows') and significant differences in begging calls of young birds, it was resurrected.

Red-tailed Black-Cockatoo pair roosting (and canoodling) in a tree by a waterhole near
Barcaldine, central Queensland, female on the right. (And try as I might I couldn't get
a vantage point where the sun wasn't behind them, though they were quite
unperturbed by us.)

Black-cockies are found throughout much of the continent except for the deep deserts, though Red-tails are found well inland where there is water. They alone are found scattered in separate populations in every Australian mainland state and the Northern Territory. Yellow-tails are found in a broad hinterland band from Eyre Peninsula in South Australia to Tasmania and the southern tropics in Queensland. They are the most familiar ones to most people, living in the heavily populated south-east. They're not typically suburban birds, though they're quite common in Canberra and are regular in and over the suburbs. Luckily for us they love the big bankia which overhangs our balcony and they drop by from time to time to sample the seeds ripening in the tough cones.

Female Yellow-tailed Black-Cockatoo in Silver Banksia, suburban Duffy, Canberra.
(She has a white bill and brown eye rings.)

This leaves three species with much more limited distributions; all are regarded as Threatened due to habitat loss (especially large hollow-bearing breeding eucalypts) and fragmentation.

The Glossy Black-Cockatoo Calyptorhynchus lathami is scattered across a large area of coastal south-eastern Australia, extending well inland in places. It is a casuarina specialist, living almost exclusively on the dust-like seeds that they extract from the cones, having selected a tree with a good proportion of ripe cones. It nips off a cone, holds it up (nearly always in its left foot) and rotates it, stripping off the woody layers and eating the tiny seeds. They must feed nearly all day to get enough. While doing so they can often be readily approached, giving themselves away by soft metallic grating creaks. 

 

They are listed as Vulnerable (ie to extinction) in each state and territory in which they occur, though the Kangaroo Island population in South Australia is Endangered.

Male Glossy Black-Cockatoo eating casuarina cones, Bawley Point, south coast
New South Wales. He has a dark bill and plain head.

Female Glossy Black, Nowra, further south down the coast. She has a white bill
and yellow-blotched head. Both sexes have red tail panels, which are the source of reports
of Red-tailed Black-Cockatoos in the south east. These are invariably incorrect
but are persistent.

While on the topics of myths around black-cockatoos, a favourite is that they are bringers of rain. Undoubtedly the two coincide on occasions, but they also turn up here regularly during drought and many a rainstorm is unheralded by cockies (or any other birds known as 'rain birds'). It's a curious one and its adherents cheerfully brush such objections aside. I admire their faith.

In the south-west of the continent are two species of white-tailed black-cockatoos, which apparently arose in wetter times when yellow-tails were able to cross from the east before the arid Nullarbor Plains closed the access. This has happened more than once and presumably the two white-tailed species arose from separate crossings, the second after the first had been there long enough to evolve into a separate species and unable to breed with their now distant relations. They are quite similar and the differences weren't recognised for a long time, until 1948 in fact. The key difference is in the beaks, which relate, naturally, to their diets. For a while they were known, logically to most of us, as Short-billed and Long-billed White-Cockatoos but (unfortunately for those of us who aren't keen on lumbering unsupecting animals with human names) they are now known as Baudin's Black-Cockatoo Zanda baudinii and Carnaby's Black-Cockatoo Z. latirostris. Both species are listed as Endangered

Carnaby's (Short-billed) Black-Cockatoos at Yanchep, north of Perth. Here they are in
their major habitat of banksia coastal heathland, where their short heavy bills are
employed in cracking open the cones, like the Yellow-tails from which they derived.

A female (white bill, large cheek patch), part of the same flock.

As well as the coastal heaths (kwongan) Carnaby's are found inland in Wandoo woodlands where there is an understorey of Banksias and related woody-seeded shrubs. They are named as a tribute to West Australian entomologist and jewel beetle expert Keith Carnaby, who recognised that two white cockatoos are present and published it in 1948. 

The 'other' species, Baudin's Black-Cockatoo, is taken from the species name, which in turn is for the French naval officer Nicholas Baudin who commanded the great scientific expedition to Australia from 1800 to 1803. By all accounts he was appallingly rude and unsympathetic to the needs of the scientists who were the point of the whole exercise, but I also note that he died on the way home and history tends to be written by the survivors.

Baudin's (Long-billed) Black-Cockatoos, Stirling Ranges NP. Unfortunately their bills are
largely obscured by the feathers (hence Calyptorhynchus!) but you get some idea of its
longer and more slender nature from the bird on the left. (I recall this morning as offering some
of the worst light I recall - at least to someone with my limited photographic skills!)

It's a pity I can't show you the bill in more detail, because it's very specialised. Like other black-cockies the top bill is very mobile, hinged to allow greater movement than that of most birds, to allow delicate grasping and great pressure to be applied. However it is also very long and slender to enable the extraction of seeds from the large woody fruit of Marri Corymbia (or Eucalyptus) calophylla, a common tree of the south-western forests and moister woodland.

The incredibly tough Marri fruits (here in John Forrest NP, near Perth) are up to 50mm long
and 35mm wide, and can form all year round, producing large numbers of seeds
over an extended period, including during the sometimes hungry days of winter.
This is a very valuable resource, worth the effort of extraction. The bill is strong
enough to crush the capsule, then the top mandible extracts the tiny seeds.

Faced with an apple, the cocky will similarly extract the seeds and ignore the flesh! This has led to many fatal interactions with orchardists, some under licence, others illegal.

 

As well as seeds, other black-cockies also eat fruit; Red-taileds are very fond of the fruit of White Cedar Melia azedarach. This tree is native to NSW, Queensland and the Northern Territory as well as across south-eastern Asia to China and Japan, and across the Pacific. It mostly lives on rainforest margins, but has been widely planted. The fruits, seeds and leaves are toxic to most mammals, but not birds. In Bourke, in far northern inland NSW (and doubtless other inland towns too), the Red-taileds can always be found in town when the White Cedar street trees are in fruit.

Red-tailed Black-Cockatoo dining in town on White Cedar fruits, Bourke.

It might be a surprise to know that they can be quite carnivorous too. Yellow-taileds are very assiduous in extracting large beetle and moth larvae from the interior of very hard eucalypts, doubtless to the surprise of the larvae who doubtless consider themselves safe there. The birds will clamber down the trunk of the tree, searching for the holes through which the grubs void their waste (frass, in case you were looking for a more technical term). It will then rip out a strip of timber with its formidable bill, until it is at about 45 degrees to the trunk, and use it as a perch from which to work, tearing the hardwood out until it reaches the luckless and luscious grub. 

Blackbutt Eucalyptus pilularis excavated by a Yellow-tailed Black-Cockatoo,
Ulladulla, south coast NSW.

They also spend a lot of time on much softer wattles too, an easier proposition from which to extract the meal, though the smaller the stem the smaller the reward too.

Yellow-tailed Black-Cockatoo working on an Acacia stem, Murramarang NP.
The holes by his left foot may be exploratory, or there may have been more
than one grub present.

So, the wonderful black-cockatoos, old Australians who still thrill us with their wailing presence in the skies, in the forests, and even, on a good day, in our yards.

Yellow-tailed Black-Cockatoo female (but you knew that!) just outside my study window,
snacking on banksia seeds and discarding the rest. I don't mind cleaning up after her..

After all, any black-cocky day is a good day.

(And because I don't want to leave the other cockies feeling miffed, I promise to write about them someday soon.)

NEXT POSTING THURSDAY 10 FEBRUARY

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