Cassowaries (Tok Pisin: muruk, Indonesian: kasuari) are flightless birds of the genus Casuarius in the order Casuariiformes. They are classified as ratites: flightless birds without a keel on their sternum bones. Cassowaries are native to the tropical forests of New Guinea (Papua New Guinea and West Papua), the Aru Islands (Maluku), and northeastern Australia.
Three cassowary species are extant. The most common, the southern cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich and emu. The other two species are represented by the northern cassowary and the dwarf cassowary; the northern cassowary is the most recently discovered and the most threatened. A fourth but extinct species is represented by the pygmy cassowary.
Around 90% of the cassowary diet consists of fruit, although all species are opportunistic omnivores, and take a range of other plant foods, including shoots and grass seeds, in addition to fungi, invertebrates, eggs, carrion, fish, and small vertebrates like rodents, small birds, frogs, lizards, and snakes. Although all ratites can eat meat, cassowaries, by definition, are the most omnivorous and, therefore, the largest omnivorous bird where meat still forms a minute part of their diet. Indeed, whilst not hypercarnivorous predators like birds-of-prey, cassowaries including juveniles are not picky eaters and are willing to eat anything that will fit in their mouths. They also have the most varied diet in protein consumption, in contrast to other ratites such as ostriches, where meat is largely used as a substitute in harsh times and is limited to mere invertebrates and small animals.
Cassowaries are very wary of humans, but if provoked, they are capable of inflicting serious, even fatal, injuries upon both dogs and people. The cassowary has often been labelled "the world's most dangerous bird", although in terms of recorded statistics, it pales in comparison to the common ostrich that is recorded to kill two to three humans per year in South Africa.
