It is the male which sits on the eggs and looks after the chicks until they are
about one year old. During this time the cassowary can be aggressive towards people
and dogs, especially if they get between himself and his chicks. In attack they
kick with their feet that are armed with fearsome claws. Dogs in packs are a real
danger to cassowaries, but other than this, the cassowary fears nothing and walks
with an imperious air about his home range, which varies with the seasons.
Stories of cassowaries killing people are an exaggeration, but if they get used to being fed by people they can become aggressive if you withhold food from them.
Being such a large bird, standing up to 2 metres tall and females
weighing up to 85 kilograms, they are able to swallow the largest of rainforest fruits.
Their digestive tract has no gizzard for grinding up their food, so most of the seeds
in the fruits are passed out unharmed and are thus distributed widely throughout the
forest. Indeed for many rainforest trees, the cassowary is its only hope for maintaining
its population spread. For this reason the cassowary is known as a Keystone Species,
and its welfare is essential to the rainforest eco-system. |
The cassowary has a distinctive casque on top of its head, which is made of a horny material. Its function is not known for certain, but it is my guess that it prevents the bird's head being scratched by 'Wait-a-while' hooks as it picks its way through the rainforest. These hooks are the whip-like flagellaria of Lawyer Vine (Calamus moti) which is actually a climbing palm. These hooks produce scratches on human skin that nearly always get infected, so perhaps the cassowary's casque is for disease prevention. Certainly if you try to follow the cassowaries in the forest, the first thing you learn to take with you is a hat.
Although their ranges change with the seasons, they also overlap at certain seasons. We often have two male cassowaries using Chakoro Nature Reserve - Freddy and Hercules. In 1996 Freddy succeeded in raising one chick through till his next breeding season. In 1997 he hatched two but they both disappeared fairly early on. In 1998 we didn't see him very often and never with chicks. In 1999 his only chick to survive to sub-adulthood was run over when Freddy was busy mating. Sadly the visiting female was also run over a couple of weeks later.
Hercules, however, managed to raise four chicks in 1998. When
they were about six months old he paraded his chicks right up to my garden fence
and challenged my dogs to 'come out and fight' by stamping and grunting and flourishing
his feathers. Knowing full well that there was a fence between them, my dalmatians,
Woody and Daisy, went up to the fence and gave a half-hearted bark. Hercules seemed to
say to his chicks "you don't have to worry about these stupid spotted ones behind the
fence, but watch out for the others, OK?" |
Cassowaries face many dangers in their natural habitat, and most chicks are lost before they become sub-adults. A healthy female may lay 3 to 5 eggs in a male's nest and may lay for more than one male, and so there are many more chicks born than the habitat can support. When the sub-adults leave their father they have to find themselves a territory, and since the mature males guard their territories very fiercely, most of the sub-adults will be killed too. Only the fittest will survive.
The impacts of modern day human society on cassowaries come from habitat destruction for agriculture and residential development, competition for food from introduced feral pigs, dog attacks, and traffic accidents. Cassowaries are very bad at crossing roads because they seem to be unable to grasp that a car off in the distance is going to be here in five seconds. We have successfully lobbied for the Queensland Government's Department of Main Roads to introduce an 80 Kph speed limit on the main road through the World Heritage Area going to Mission Beach, and going past Chakoro Nature Reserve.
|"Cassowary" by Leonard Andy|