Cassowaries: Casuaridae

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CASSOWARIES: Casuaridae

SOUTHERN CASSOWARY (Casuarius casuarius): SPECIES ACCOUNT

PHYSICAL CHARACTERISTICS

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.

GEOGRAPHIC RANGE

Cassowaries are found in northern Australia, Papua New Guinea, and surrounding islands.

HABITAT

Cassowaries live in rainforest, ranging from lowland swamp forests to mountainous forests.

DIET

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.

ATTACK OF THE BIG BIRDS

Cassowaries are considered the most dangerous bird in the world. Though normally shy, when cornered or threatened, the cassowary will lash out, charging their victim, kicking and slashing with their razor-sharp claws. In 1999 there were 144 documented cassowary attacks on humans in Australia, six causing serious injury. There were also cassowary attacks on dogs, horses, and one cow. The last reported death from a cassowary attack occurred in 1926 when a sixteen-year-old boy was killed by a single kick to the neck after hitting the bird with a stick.

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.

CONSERVATION STATUS

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.

SOUTHERN CASSOWARY (Casuarius casuarius): SPECIES ACCOUNT

Physical characteristics: Southern cassowaries are 50 to 67 inches (127 to 170 centimeters) in length. Females weigh about 128 pounds (58 kilograms) and males weigh 64 to 75 pounds (29 to 34 kilograms). The neck skin is red and blue and the feathers of adults are glossy black. They have two long, red wattles, which are folds of unfeathered skin that hang from the neck.

Geographic range: Southern cassowaries are found in Queensland in two areas of northern Australia: the wet tropics from Mt. Halifax to Cooktown, and on Cape York Peninsula. They also live in Papua New Guinea.

Habitat: They live primarily in lowland rainforests below 3,600 feet (1,100 meters).

Diet: Southern cassowaries are omnivores, meaning they eat both plants and flesh. Their diet consists mainly of fruit but they will also eat flowers, lizards, snakes, snails, small marsupials, and birds.

Behavior and reproduction: During the breeding season in June and July, the female lays one to four lime green 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.

Southern cassowary and people: Once common throughout its natural range, the southern cassowary is now rarely seen in the wild. In Australia and Papua New Guinea, the southern cassowary is part of the mythology and culture of the indigenous peoples. The birds are still hunted and chicks are captured and raised in pens until they become adults, then slaughtered for meat.

The southern cassowary needs large areas of rainforest to survive and protected areas, such as national parks, are not enough. Conservationists in the two southern cassowary population areas have been using different methods to combat this problem. They have established nurseries to grow rainforest fruit trees that can be replanted in cleared land, as well as forming corridors between two separated habitats.

Conservation status: The southern cassowary is listed by IUCN as Vulnerable due to rapidly declining populations. The Australian government has listed the southern cassowary as an Endangered species. Estimates in Australia place the total population at 1,200 to 1,500 individuals. The populations are declining due to loss of habitat, deaths by vehicles, dogs, wild pigs, and illegal hunting. ∎

FOR MORE INFORMATION

Books:

Clements, James F. Birds of the World: A Checklist. Vista, CA: Ibis Publishing Co., 2000.

Davies, S. J. J. F., et al. Ratites and Tinamous: Tinamidae, Rheidae, Dromaiidae, Casuariidae, Apterygidae, Struthionidae (Bird Families of the World, Volume 8). Oxford, U.K.: Oxford University Press, 2002.

Elwood, Ann, and John B. Wexo. Ostriches, Emus, Rheas, Kiwis, and Cassowaries (Zoo Books). Mankato, MN: Creative Education, 2000.

Periodicals:

Baker, Jordan. "Qld: Cassowary Numbers Falling." Asia Africa Intelligence Wire (September 13, 2002).

"Be Wary, Cassowary." U.S. Kids (March 1998): 19–22.

Bond, Ruskin. "The Elephant and the Cassowary." Highlights for Children (February 1997): 25.

"Cassowary Talks to Mates in a Low Tone." Asia Africa Intelligence Wire (November 6, 2003).

Mack, Andrew L., and Gretchen Druliner. "A Non-Intrusive Method for Measuring Movement and Seed Dispersal in Cassowaries." Journal of Field Ornithology (April 2003): 193–196.

Mack, Andrew L., and Josh Jones. "Low-Frequency Vocalizations by Cassowaries." The Auk (October 2003): 1062–1068.

Nihill, Michael. "Dangerous Visions: The Cassowary as Good to Think and Good to Remember Among the Anganen." Ocean (June 2002): 258–275.