Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"

Having told you all about Emus, I think the time is right to also mention their more colourful cousins, the Cassowaries. This is a Southern Cassowary, Casuarius casuarius, also called a double-wattled cassowary. This is the only cassowary that occurs natively both on New Guinea and on the mainland of Australia. Two other cassowary species are currently recognized – The Northern or Single-wattled Cassowary, and the Dwarf or Bennett's Cassowary, both of which occur only on New Guinea. The southern is the largest. It is not as tall as the Emu, reaching about 170 cm/5'7", but heavier; some females can reach a weight of 58 kg/128 lbs.

Cassowaries are probably the most spectacular of the world's large flightless birds, with their bold colours and head adornments. Their most unusual feature is the large helmet-like casque they have on top of their heads. It is not solid, but filled with a light, spongy tissue containing some blood vessels. We're not entirely sure what it is for, but it might play a role in 'pushing away' dense leaves and twigs as the bird moves through dense bushes, or it might help with cooling the bird down in the hot, humid tropical climate. Or it might be used as a shovel, to dig and shove leaf litter aside while the bird forages. Being a striking visual feature, it might also be used in display. Both the male and the female have the tall casque. That of the southern cassowary is the tallest, and that of the dwarf cassowary the lowest. Apart from the casque, the cassowary is also decorated with bright, bare facial skin and pendulous wattles. The pattern differs between the species and even between individuals. The southern cassowary has the bare skin mainly red and blue, while the single-wattled cassowary often have bright yellow and orange colours as well.

The natural habitat of cassowaries is tropical rainforest. On Australia, these are found today only in comparatively small patches in mountainous terrain in the far northeast, close to the coast. Rainforest is much more extensive on New Guinea, where it still clothes the majority of that huge island. But the birds on New Guinea sometimes also move into more open habitats like savannah. It may seem strange that the southern cassowary occurs both there and also in Australia, in spite of the sizeable sea strait that separates the two. But two factors need to be considered. First, like emus, cassowaries can actually swim quite well. So they might have been able to make it across a stretch of ocean. But maybe they didn't have to. Australia and New Guinea is actually a single landmass, and the sea separating them shallow. During the ice ages, the last of which ended quite recently, about ten thousand years ago, ocean levels were much lower, with so much water locked up in glaciers. There would have been times when the seabed of the present strait would have been exposed so that any animal or flightless bird could walk from New Guinea to Australia, and vice versa. Indeed, it seems that at least the dwarf cassowary in the past also ranged down far into Australia.

In their rainforest homes, double-wattled cassowaries are at present the largest residents both in New Guinea and Australia. They have no major natural predators. Nevertheless, they are very well-defended, since in fairly recent times there were large predators, now extinct, that roamed the forests. Cassowaries have very long, sharp claws on their innermost toes. (Like emus, they have three toes per foot.) They can use this as a dagger-like weapon in a powerful, double-foot forward kick. Before attacking, they'll deploy a threat display that includes rearing up and raising the body feathers to look bigger, as well as uttering a booming call. They've been known to kill humans, though this happens very rarely. They can also run fast, though not over long distances. They have long, coarse, blackish 'feathers' on their bodies, that actually look more like shaggy hair. The feathers on their wings have been reduced to five or six long, bare shafts, looking like the quills of a porcupine. Their shaggy body feathers and long wing-quills are resistant to damage as they rub against trees and shrubs, while pushing through the jungle. Their legs are covered in tough scales at the front, and as mentioned, their heads are protected by their casques.

We actually still don't know much about the behaviour of cassowaries in the wild. They can be surprisingly hard to see, skulking and hiding in the dense forest. They mostly seem to occur singly or in pairs. They're omnivorous, but eat mainly plant foods like fruit. They can swallow sizeable fruits whole; they either peck up fruits fallen from trees, or pluck fruits from low bushes. They also eat fungi, invertebrates, small vertebrates, and carrion. They make deep, throbbing calls similar to those of emus, as well as a variety of hisses, whistles, roars and bill-claps, and in the breeding season, the male makes a grunting 'boo-boo-boo' call. Their eggs, like those of emus, are greenish, but usually a bit lighter in tone than those of emus. As in that species, the incubation and chick care is performed by the male. Chicks are prettily coloured in reddish-brown down with dark stripes along their bodies. They lack casques; these develop slowly and keep growing into adulthood. They reach sexual maturity at two and a half to three and a half years; in captivity, cassowaries have lived for forty years.

Cassowaries have always been popular in various ways with humans. They're hunted for their meat in New Guinea, but also kept semi-domesticated; they've been introduced in ancient times to islands beyond their native occurrence, like Seram and New Britain. They're considered valuable items of trade. Their long body feathers are used for ceremonial headdresses; their wing-quills as ornaments for nose or ear piercings; their sharp inner claws to make tips for arrows; their bones for daggers, spoons or scrapers. Sadly, they don't seem to breed well in captivity. They are presently in some danger due to human activity, primarily the ongoing destruction of their forest homes. In Australia, many patches of forest are now separate from each other, and cassowaries sometimes need to cross roads to disperse. They also suffer from feral pigs trampling and eating their eggs and chicks.

Willem

10.07.23 Front Page

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