It is unknown whether cassowaries have any natural predators, but humans could be considered a predator because cassowaries are sometimes eaten by humans.
Known Predators:
Southern cassowaries are large, robust birds with long powerful legs for running and defense; the claws on the toes are up to 12 cm long. Their bodies are covered with dark brown or black feathers which look more like thick, coarse hair. The neck and head have no feathers and are boldly colored blue and red. On their heads there is a large bony casque which is made of trabecular bone and cartilage. The wings are extremely small and there are vestiges of primary feathers in the form of five or six long white spines. Cassowary chicks are brown with black stripes running the length of their bodies for their first three to six months. Juveniles are brown instead of black and have smaller casques. They do not get the vividly colored necks until they are about one year old. Females are 127 to 170 cm long and up to 59 kg, are larger than the males which are 29 to 34 kg. Southern cassowaries are the largest of the three species of cassowary and the only species to have have two bright red flaps of skin, called wattles, hanging from their neck.
Range mass: 29 to 59 kg.
Range length: 102 to 170 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
There is little known about the lifespan of southern cassowaries in the wild, but in captivity southern cassowaries have lived 20 to 40 years.
Range lifespan
Status: captivity: 20 to 40 years.
Southern cassowaries live primarily in lowland rainforests, typically less than 1,100 meters elevation, and occasionally are found in eucalyptus forests, savannas, palm scrub, and in forested swamps.
Range elevation: 0 to 1,100 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; rainforest ; scrub forest
Southern cassowaries communicate with each other by issuing very loud deep roars which travel well through the forest. These roars are up to 40 decibels louder than the surrounding forest noise, and are at frequencies which are at the very bottom end of what humans can perceive, about 23 Hertz. Cassowaries are one of the only birds to have been recorded making vocalizations this low. There is some speculation about whether the casques on their heads are somehow related to these impressive sounds. It is speculated that the casque could play a role in receiving or producing these sounds. These calls are territorial, warning other cassowaries of their presence.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
The biggest threat to southern cassowaries is the destruction of their habitat. These birds are also sometimes killed by cars and their populations are disrupted by feral pigs and dogs. There has been a 30% decline in their numbers in the last 30 years. Fortunately, in Australia, the destruction of habitat has almost completely stopped and in New Guinea there are large areas where the bird is not hunted which helps their numbers. Southern cassowaries will be safe as long as there are large areas of undisturbed forests.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: vulnerable
Although they are usually shy, southern cassowaries can be aggressive towards people, especially when kept in captivity. Southern cassowaries will charge people, jumping at them while slashing with their 12 cm claws. They can cause serious injury and sometimes death. In 2004 southern cassowaries were voted by the Guinness Book of World Records as the worlds most dangerous bird for these reasons.
Negative Impacts: injures humans
Southern cassowaries are important in the mythology of the indigenous peoples of New Guinea and Australia. These birds are captured as chicks and raised in villages so that their feathers can plucked and used in headdresses and the quills can be used as nose ornaments. Eventually, when the birds reach a certain size they are killed for food. There has been a trade of cassowaries in Southeast Asia for over 500 years. It is possible that populations of southern cassowaries on Australia and some of the islands surrounding New Guinea are the result of human introductions through trade.
Positive Impacts: food ; body parts are source of valuable material
Cassowaries live primarily on fruit from a large number of species of trees. When cassowaries eat the fruit the seeds pass through their system and are dispersed far from where they originally fell. The seeds are often still viable after passing through the digestive system of cassowaries. In a typical pile of cassowary dung there can be as much as one kilogram of seeds. In a study of the effects of seed dispersal by cassowaries, the seeds from 78 species of plants were found and 70 of these species' seeds were able to germinate after being passed through the cassowaries. Some of the species found in cassowaries dung include Davidsonia pruriens, Acemena divaricata, Polyalthia michaelii, Acronychia acronychioides and a large number from the Lauraceae family.
Ecosystem Impact: disperses seeds
Mutualist Species:
Southern cassowaries are frugivorous, feeding mostly on fruits from canopy species in the forests where they live. Because these birds cannot fly they must rely on finding fruit that has fallen to the ground. They also eat insects, small vertebrates, and fungi. Inspection of the feces reveals that commonly ingested fruits are Davidsonia pruriens, Acemena divaricata and members of the laurel family (Lauraceae).
Animal Foods: mammals; amphibians; reptiles; insects; terrestrial non-insect arthropods
Plant Foods: fruit
Other Foods: fungus
Primary Diet: herbivore (Frugivore )
Southern cassowaries are found in New Guinea, Cape York, Ceram and Aru Islands.
Biogeographic Regions: australian (Introduced , Native ); oceanic islands (Introduced , Native )
Other Geographic Terms: island endemic
Females are polyandrous; a female will usually breed with two to three males throughout the mating season, starting a new nest every time, which the male will incubate. Courtship consists of the males making a “boo-boo-boo” call while inflating his throat.
Mating System: polyandrous
The breeding season is in winter, when fruit is most abundant. The nest is a pad of vegetation on the ground and there are typically about 4 bright green eggs in a clutch. Incubation, which is exclusively done by the males, lasts for 47 to 61 days. Once the chicks hatch they stay with their father until they become independent at about nine months. At about three years of age, southern cassowaries are able to reproduce.
Breeding interval: Females will mate with 2 to 3 males during the mating season.
Breeding season: Breeding occurs during the austral winter, from June to July.
Range eggs per season: 4 to 8.
Range time to hatching: 47 to 61 days.
Average time to independence: 9 months.
Average age at sexual or reproductive maturity (female): 3 years.
Average age at sexual or reproductive maturity (male): 3 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
After the eggs are laid all care of the eggs and offspring are done by males. Males construct a mat of vegetation which will become the nest where they incubate the eggs for 47 to 61 days. The chicks are precocial at hatching, but dependent on their male parents for protection from predators and for teaching them how to find food for themselves. This period will last for about 9 months, when the males will abandon the juvenile cassowaries.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Male, Protecting: Male); pre-weaning/fledging (Provisioning: Male, Protecting: Male); pre-independence (Provisioning: Male, Protecting: Male)
The southern cassowary (Casuarius casuarius), also known as double-wattled cassowary, Australian cassowary or two-wattled cassowary,[3] is a large flightless black bird. It is one of the three living species of cassowary, alongside the dwarf cassowary and the northern cassowary. It is a ratite and therefore related to the emu, ostriches, rheas and kiwis.
Presently, most authorities consider the southern cassowary monotypic, but several subspecies have been described.[4] It has proven very difficult to confirm the validity of these due to individual variations, age-related variations, the relatively few available specimens (and the bright skin of the head and neck – the basis upon which several subspecies have been described – fades in specimens), and that locals are known to have traded live cassowaries for hundreds, if not thousands of years, some of which are likely to have escaped/been deliberately introduced to regions away from their origin.[4]
Cassowaries are closely related to the kiwis, both families diverging from a common ancestor approximately 40 million years ago.[4]
The binomial name Casuarius casuarius is derived from its Malay name kesuari.[5] The southern cassowary was first described by Carl Linnaeus, in his 18th-century work Systema Naturae, as Struthio casuarius,[6] from a specimen from Seram, in 1758.[3] It is now the type species of the genus Casuarius.[3]
The southern cassowary has been described under a large number of scientific names, all of which are now considered taxonomic synonyms for the species.[7]
The southern cassowary has stiff, bristly black plumage, a blue face and a long neck, red on the cape and two red wattles measuring around 17.8 cm (7.0 in) in length hanging down around its throat. A horn-like brown casque, measuring 13 to 16.9 cm (5.1 to 6.7 in) high, sits atop the head. The bill can range from 9.8 to 19 cm (3.9 to 7.5 in). The three-toed feet are thick and powerful, equipped with a lethal dagger-like claw up to 12 cm (4.7 in) on the inner toe. The plumage is sexually monomorphic, but the female is dominant and larger with a longer casque, larger bill and brighter-coloured bare parts. The juveniles have brown longitudinal striped plumage. It is perhaps the largest member of the cassowary family and is tied as the third heaviest bird on earth (after the Somali ostrich and the common ostrich), at a maximum size estimated at 85 kg (187 lb) and 190 cm (6 ft 3 in) tall. Normally, this species ranges from 127 to 170 cm (4 ft 2 in to 5 ft 7 in) in length.[3] The height is normally 150 to 180 cm (4 ft 11 in to 5 ft 11 in) ; females average 58.5 kg (129 lb), while males average 29 to 34 kg (64–75 lb). The northern cassowary is about the same size on average and is perhaps very mildly less sexually dimorphic than the southern.[3] Most adult birds will weigh between 17 and 70 kg (37 and 154 lb).[8] It is technically the largest Asian bird (since the extinction of the Arabian ostrich) and the largest Australian bird (though the emu may be slightly taller).
The southern cassowary is distributed in Indonesia, Papua New Guinea and northeastern Australia.[9] It mainly inhabits tropical rainforests but may make use of nearby savannah forests or mangroves stands.[2] The species prefers elevations below 1,100 m (3,600 ft) in Australia,[3] and 500 m (1,600 ft) on New Guinea.[2]
Southern cassowaries forage on the forest floor for fallen fruit and are capable of safely digesting some fruits toxic to other animals. They also eat fungi, and some insects and small vertebrates. Inspection of the feces reveals that commonly ingested fruits are Davidsonia pruriens, Syzygium divaricatum and members of the laurel family (Lauraceae).[10]
The southern cassowary is a solitary bird, which pairs only in breeding season, in late winter or spring. The male builds a nest on the ground,[3] a mattress of herbaceous plant material 5 to 10 centimetres (2–4 in) thick and up to 100 centimetres (39 in) wide. This is thick enough to let moisture drain away from the eggs. The male also incubates the eggs and raises the chicks alone. A clutch of three or four eggs are laid measuring 138 by 95 millimetres (5.4 in × 3.7 in). They have a granulated surface and are initially bright pea-green in colour although they fade with age.[3][11] Southern cassowaries make a thunderous call during mating season and hissing and rumblings otherwise. Chicks will make frequent high-pitched contact whistles and chirps to call the male.[2]
Southern cassowaries have a reputation for being dangerous to humans and animals, and are often regarded as aggressive. The birds can jump quite high and kick powerfully with their blade-like claws. However, deadly encounters with southern cassowaries are rare. Only two human deaths have been reported since 1900. A 2003 historical study of 221 southern cassowary attacks showed that 150 had been against humans: 75% of these had been from southern cassowaries that had been fed by people, 71% of the time the bird had chased or charged the victim, 15% of the time they kicked. Of the attacks, 73% involved the birds expecting or snatching food, 5% involved defending their natural food sources, 15% involved defending themselves from attack, and 7% involved defending their chicks or eggs. Only one human death was reported among those 150 attacks.[12]
The first documented human death caused by a southern cassowary was on April 6, 1926. In Australia, 16-year-old Phillip McClean and his brother, age 13, came across a southern cassowary on their property and decided to try and kill it by striking it with clubs. The bird kicked the younger boy, who fell and ran away as his older brother struck the bird. The older McClean then tripped and fell to the ground. While he was on the ground, the cassowary kicked him in the neck, opening a 1.25 cm (0.5 in) wound that may have severed his jugular vein. The boy died of his injuries shortly thereafter.[13]
Another human death due to a southern cassowary was recorded in Florida on April 12, 2019. The bird's owner, a 75-year-old man who had raised the animal, was apparently clawed to death after he fell to the ground.[12]
Being fed by people tempts southern cassowaries into closer associations with human-inhabited areas, increasing the already high risk of vehicle strikes - a major cause of southern cassowary mortality - and increasing the likelihood of encounters with humans.[14] Many "aggressive" birds are simply responding to having been fed by humans in the past. Unfortunately the poor reputation of this species leads to confusion and misinformation among the public, which hampers conservation efforts of this shy bird.
In a 2017 Australian Birdlife article, Karl Brandt suggested Aboriginal encounters with the southern cassowary may have inspired the myth of the bunyip.[15]
Although subject to ongoing habitat loss, limited range, and overhunting in some areas, the southern cassowary was evaluated as Least concern in 2018 by the International Union for Conservation of Nature (IUCN).[2] The Australian population is listed as Endangered under Federal and Queensland State legislation.[16] Some threats are habitat loss (logging), feral animals eating their eggs, hunting, and roadkill.[2][3] Road building, feral animals and hunting are the worst of these threats. It has an occurrence range of 396,000 km2 (153,000 sq mi), and between 10,000 and 20,000 birds were estimated in a 2002 study, with between 1,500 and 2,500 in Australia.[2] Southern cassowaries have been bred in many zoos around the world, like at White Oak Conservation in Yulee, Florida, United States.[17]
Upper body
Egg at Museum Wiesbaden
Chick at Artis Zoo, Netherlands
An older juvenile walking across a road in Australia
Adult male with two chicks at Artis Zoo
Mount Hypipamee National Park, Australia
The southern cassowary (Casuarius casuarius), also known as double-wattled cassowary, Australian cassowary or two-wattled cassowary, is a large flightless black bird. It is one of the three living species of cassowary, alongside the dwarf cassowary and the northern cassowary. It is a ratite and therefore related to the emu, ostriches, rheas and kiwis.
.jpg)
