Cassowaries on the Daintree Coast

The Southern Cassowary is so named because it also occurs on the Southern slopes of New Guinea's mountains. Cassowaries are probably best known as fruit eaters, but they will eat just about anything, including small birds, insects and rodents. They are also intensely curious, but sadly not very bright, which can lead to some rather unfortunate incidents.

The Daintree Coast is a critical habitat and a ‘ hot spot ’ for the Southern Cassowary which is classified as an endangered species. The main road to Cape Tribulation area cuts through the home ranges of at least four different birds. These locations are marked by cassowary signs. When you see the cassowary road sign SLOW DOWN. Vehicle traffic is the number one cause of adult cassowary deaths. Never feed a cassowary, it puts other visitors at risk. Cassowaries can be very dangerous, especially if "you don't come up with the goods", and it puts the cassowary at risk at well. Besides, it's illegal.

Cassowaries can grow up to two metres tall and weight 85 kilograms. But apart from their size, they also have a formidable dagger-like claw on each foot, and can run up to 50 km/hr. They have a striking blue head with bright red wattles, and a glossy black coat.The elongated structure on top of the cassowary's skull, called a casque, is filled with a network of very thin bone. The reason that cassowaries evolved casques is still debated, but the protruding structures may help them poke through the dense vegetation of their rainforest habitat without hurting their heads. You can see a great skull photo which rotates at the California Academy of Science web site.

Juvenile cassowaries are brown – and if really young, are striped. The male usually does the guarding of the juveniles, but occasionally both parents share the job. Don’t expect just to ‘see’ cassowaries – they are fairly reclusive here – and cross the roads, only if they need to. Main spotting areas are Cooper Creek flats (between Cooper Creek and Thornton beach), Noah flats, (between Thornton’s beach and Noah Creek), and occasionally on the Alexandra Range.

Why are Cassowaries so important?

Rainforests would be a very different place with diminished diversity if there were no cassowaries. These huge birds are the only animals capable of distributing the seeds of more than 70 species of trees whose fruit is too large for any other forest dwelling animal to eat and relocate.

If these trees did not have an animal to disperse their seeds, they would only occur in concentrated pockets around the parent tree or in places where the seeds rolled such as gullies or the bottom of slopes. As a result over a long period of time the structure of large tracts of forest might change.

In tropical rainforests in other parts of the world there are a wide range of animals which fulfill this role. In the Wet Tropics the cassowary plays the role which is accomplished by entire guilds of animals elsewhere.

There are at least another 80 species of plants which are also assisted by the cassowary's eating habits. These species have smaller seeds but many are toxic and only the cassowary can safely consume them. Such dangerous eating habits are possible because the cassowary has a short/rapid digestive system which appears to be supported by an overactive liver and an unusual combination of stomach enzymes.

Other animals such as White-tailed Rats may help distribute these smaller seeds but more often than not, they damage the seed rather than dispersing it intact. Flying foxes also distribute a wide range of large seeds, but not the extremely toxic ones that are the cassowary's specialty. So the cassowary is vital for the widespread continuance of over 150 species of plants. That is why the cassowary is referred to as a “ keystone species ”.