Class: AVES

Order: CASUARIIFORMES

Family: CASUARIIDAE

Genus: CASUARIUS

The cassowary is often called ‘the most dangerous bird on Earth’. Whilst the large foot-claws of the cassowary are definitely capable of killing, cassowary-induced fatalities are very rare, mainly because human-cassowary interactions are rare, let alone attacks which number just 200 a year.

This genus of large, flightless birds is closely related to the emu. There are three living cassowary species, of which the double-wattled cassowary is the largest. The single-wattled cassowary is smaller, but is still larger than the dwarf cassowary, the smallest species, which has no wattle. All three are found around Oceania, particularly in tropical rainforest. Although the emu is the closest living relative to the cassowary, it lacks many of the cassowary’s defining features – such as wattles, or to a greater extent, the casque on the cassowary’s head. The evolution of these features remains mysterious, though it is thought that perhaps populations would have evolved these features as a result of isolation. In all, relatively little is known about the cassowary's evolution, though fossils attributed to cassowaries date as early as the Pleistocene 10 million years ago.

Adorning the cassowary’s body is a layer of black, glossy quill-like plumage. Such plumage may absorb heat, but helps to keep the cassowary concealed in the dark jungle. Similar to their relatives, the cassowary’s foot has three toes. The wings of the cassowary are unimpressive and simple, with five prongs poking out beneath a layer of feathers. A flightless bird, these wings are used only to push away vegetation. The blue head of the cassowary lacks plumage, and is instead covered with bumpy skin, similar to scales, albeit softer.

The casque on the head of the cassowary can grow to about 17 centimetres in height, and is probably used as an offset to thermal radiation.

Areas of the neck may be reddish, though this is seemingly lacked on the Dwarf Cassowary’s neck. The aptly-named double-wattled cassowary has two pink wattles poke out of its neck, and the single-wattled cassowary has just one. The Dwarf Cassowary lacks a wattle of any kind, though otherwise it looks very similar to the Double-Wattled Cassowary. Young cassowaries, however, lack many of these spectacular features, and are instead yellowish, striped and spotted. Juvenile cassowaries will grow some of these features, but will retain a brown plumage. In adulthood, the plumage darkens. On the head of all three cassowaries is a sizable casque, perhaps used as an offset to thermal radiation – with dark plumage, it helps for the casque to make the cassowary lose some amount of heat. Despite a bulky size, the cassowaries are indeed very agile, capable of leaping towards what could be considered a threat.

The varying presence of the cassowary’s wattles is an obvious indicator of the species. This is a double-wattled cassowary, named as such as it has two wattles.