The Casuarius, commonly known as the cassowary, is a large, flightless bird native to the tropical forests of New Guinea, nearby islands, and northern Australia. Notable for its striking blue and black plumage, helmet-like casque, and powerful legs, it is an adept runner and can be aggressive when threatened.

Casuarius, commonly known as cassowaries, are native to the tropical forests of New Guinea, surrounding islands, and northern Australia. The three species within this genus are distributed as follows: the Southern Cassowary (Casuarius casuarius) is found primarily in the lowland rainforests of northern Australia, New Guinea, and nearby islands; the Northern Cassowary (Casuarius unappendiculatus) is native to the northern parts of New Guinea; and the Dwarf Cassowary (Casuarius bennetti) is found in the montane forests of New Guinea, New Britain, and Yapen Island.

Cassowaries inhabit dense tropical rainforests, which provide abundant fruit and cover. They thrive in humid, warm environments with consistent rainfall, typical of tropical climates. These areas often have lush vegetation, including a variety of fruit-bearing trees and dense undergrowth.

Cassowaries play a crucial role as seed dispersers in their ecosystem. They consume a wide variety of fruits and transport seeds over long distances through their droppings, facilitating forest regeneration and biodiversity. Their presence helps maintain the structure and health of rainforest ecosystems. Cassowaries are primarily solitary and territorial, with each bird maintaining a home range that supplies its dietary needs.