Cassowaries are the most colourful of the ratites. Their black bodies, blue heads and red wattles make them easy to identify. There are three species, all of which are found in Papua New Guinea.
The largest, the Double-wattled Casuarius casuarius cassowary is perhaps the best known as it also lives in north eastern Australia and several islands around PNG. It is a species of rainforests. The slightly smaller Single-wattled Cassowary Casuarius uppendiculatus lives mostly in river valleys and swamps only in PNG and nearby islands. The Dwarf Cassowary Casuarius bennetti also from PNG and adjacent islands is a specialist of montane forests and is rarely seen below 1000 m (3500 ft).
Little is known about the ecology of Cassowaries and most of that applies only to the two larger species. Double-wattled Cassowaries can stand 1.5 m (5 ft) tall and weigh over 55 kg (100 lbs). Cassowaries are good runners, despite being forest dwellers not plains dweller like their close relatives. They all carry a growth on their foreheads called a casque which is believed to help them push through the underbrush. Cassowaries' feathers have lost much of their complexity and have become just long quills, more like thick hair than feathers. This thick coat helps to protect them against the dense underbrush which they run through at speeds of up to 45 kph (30 mph). Cassowaries do not always run away, they have sharp claws and can defend themselves by kicking violently. Several people have been killed by them in this way.
Unlike Emus, Ostriches and Rheas, Cassowaries are territorial all year round and live in pairs. Territories range in size from 1-5 km square (1/3 - 2 miles square) and the pair wander around within their territory during the year, feeding on various fruits and other vegetation as it comes into season. The 3-6 large green eggs are laid in a forest between May and September. The male does all the incubation (about 50-60 days) and the precocial young are striped when first born but soon take on a more dappled appearance. Cassowaries, like Emus and Rheas, have 3 toes to their feet.