Cassowaries are large, long-legged birds. They range in height from 40 to 67 inches (102 to 170 centimeters and weigh 30 to 130 pounds (14 to 59 kilograms). They have tiny wings with coarse, black feathers.
They belong to a group of birds called ratites, which are flightless birds that have a flat breastbone rather than a keeled breastbone like birds of flight. They have a simplified wing bone structure, strong legs, and no feather vanes, making it unnecessary to oil the feathers. Consequently, unlike most birds they have no preen gland, a gland on the rear of most birds which secretes an oil the birds use in grooming.
Their heads are a brilliant blue and purple color, topped with a casque, or helmet, on the top. They have long, red wattles, folds of unfeathered skin, that hang from the neck, much like those of a turkey.
Cassowaries are found in northern Australia, Papua New Guinea, and surrounding islands.
Cassowaries live in rainforest, ranging from lowland swamp forests to mountainous forests.
Cassowaries are omnivores, meaning they eat both plants and flesh. Their diet consists mainly of fruit, but they will also eat lizards, snakes, small marsupials (animals that have a pouch), and other birds.
BEHAVIOR AND REPRODUCTION
Cassowaries are solitary birds except during mating and the egg-laying period. They are normally shy but when threatened, can attack, kicking and slashing victims with their sharp claws. Although they do not fly, they are good swimmers and fast runners.
A male cassowary is territorial, meaning it is protective of an area it considers home and claims exclusively for itself and its mate. A male’s territory is approximately 2.8 square miles (7 square kilometers) in size. Females have overlapping ranges belonging to several males.
During the breeding season that starts in May or June, the female lays three to eight large, dark, bright green or greenish blue eggs in a nest that is incubated by the male. The female then moves on to lay eggs in several other males’ nests. Incubation lasts from forty seven to sixty one days. The male cares for the chicks for nine months after they hatch.
After about nine months, the young cassowaries leave the nest and the males go off in search of an area they can claim as their own territory. The average lifespan of cassowaries in the wild is believed to be forty to fifty years.
The big birds play a critical role in the health of the rainforest of northern Australia and New Guinea by dispersing the seeds of more than 150 types of trees through their excretions. It is the only way seeds of at least eighty trees get dispersed.
Two species of cassowaries, the dwarf cassowary and the southern cassowary, found in the rainforests of Papua New Guinea, make a very low booming sound, deeper than that of most birds, that can barely be heard by humans.
Scientists believe the sounds are meant to call for a mate or to claim a territory. “Such low frequencies are probably ideal for communication among widely dispersed, solitary cassowaries in dense rainforest,” wrote Andrew L. Mack, a scientist with the Wildlife Conservation Society, in the October 2003 issue of the scientific journal The Auk. “The discovery of very low-frequency communication by cassowaries creates new possibilities for studying those extremely secretive birds and for learning more about the evolution of avian vocalizations.”
CASSOWARIES AND PEOPLE
Humans have hunted Cassowaries for hundreds of years for their meat and feathers. Hunting cassowaries is now illegal in Australia. They do not breed well in captivity and there are only about forty cassowaries in Australian zoos and wildlife parks.
The dwarf cassowary is listed by IUCN as Near Threatened, not currently threatened, but could become so. The southern cassowary and northern cassowary are listed by IUCN as Vulnerable, facing a high risk of extinction in the wild, due to rapidly declining populations. The total number of the three species of cassowary is estimated at 1,500 to 3,000, although several estimates range up to 10,000.