The call of dwarf cassowaries consists of low, booming tones that resonate at a frequency near the lower end of human hearing. This low-frequency communication is ideal for solitary birds that occur at low densities in thick forests, as dwarf cassowaries do. Little is known about communication when dwarf cassowaries meet to mate, although visual cues may be involved.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Dwarf cassowaries are hunted extensively but populations seem to be stable at this time. Habitat destruction and excessive hunting could threaten populations.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: near threatened
Dwarf cassowaries have been known to attack humans when provoked. Using their strong legs and sharp claws, several deaths of humans have been recorded as the result of cassowary attacks.
Negative Impacts: injures humans
Dwarf cassowaries are kept in captivity as pets and sometimes traded locally. Cassowaries are sometimes hunted by local tribes for their meat and feathers.
Positive Impacts: pet trade ; food
Members of the genus Casuarius are responsible for the distribution of large fruits for about 70 species of trees. The fruits of these trees are too large for many other forest dwelling fruit eaters to disperse. They also play a role in the dispersal of smaller seeds for about 80 plant species. These seeds are often toxic, but can be consumed by members of Casuarius because of their rapid digestive system. Members of Casuarius are considered keystone species.
Ecosystem Impact: disperses seeds; keystone species
Dwarf cassowaries feed mainly on fallen fruits or fruits that they pluck from shrubs. Dwarf cassowaries also use the crest on their head to sort through leaf litter and reveal other sources of food, such as fungi, insects, plant tissue, and small vertebrates, including lizards and frogs.
Animal Foods: amphibians; reptiles; insects
Plant Foods: leaves; seeds, grains, and nuts; fruit
Other Foods: fungus
Primary Diet: herbivore (Frugivore )
Casuarius bennetti is found on the island of New Guinea. The majority of the population resides in Papua New Guinea, on the eastern side of the island. These birds are also found on the islands of New Britain and Yapen but their presence on these islands is likely due to extensive trade in cassowaries from New Guinea.
Biogeographic Regions: australian (Native )
Other Geographic Terms: island endemic
Dwarf cassowaries are regarded as high altitude birds in relation to other cassowaries. Their habitat is steep mountainous terrain up to 3000 m (10000 ft) that is thickly vegetated with subtropical to tropical forests.
Range elevation: 3000 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Members of the genus Casuarius have been known to live up to 40 years in captivity and possibly to 60 years in the wild, although these claims of age in the wild are unconfirmed. Age can be estimated using the appearance of the casque, the size of the footprint, and the presence of wrinkles on the neck. Lifespan in dwarf cassowaries has not been documented.
Average lifespan
Status: captivity: 26 years.
Dwarf cassowaries are the smallest of the cassowaries (Casuariidae). They stand about 99 to 135 cm (39 to 53 in) tall when measured to the top of the head and weigh around 18 kg (39 lb). Their plumage is black and coarse, while their feathers are similar to drooping bristles. Dwarf cassowaries have wings that are much reduced and they are flightless. The head and neck are lacking in feathers and are blue and red in color. The top of their head is crowned with a horny “casque,” which is similar to a bony helmet. Dwarf cassowaries, unlike their near relatives, do not have colored wattles of flesh hanging from their necks. Their legs do not have feathers and are solid and powerful. Dwarf cassowaries have three toes and the innermost toe has an enlarged claw, which can be up to 10 cm (4 in) in length. Females and males are monomorphoric, although females are larger than males.
Average mass: 18 kg.
Range length: 99 to 135 cm.
Sexual Dimorphism: female larger
Other Physical Features: endothermic ; bilateral symmetry
Dwarf cassowaries have a large claw on their innermost toe and a powerful kick that they use to defend themselves when provoked. Dogs are considered predators of Casuarius species, particularly older birds, hatchlings, and sub-adults. Feral (introduced) pigs are also predators of Casuarius because they eat the eggs of these birds and are potential predators of hatchlings and young birds. Humans occasionally hunt cassowaries for their meat and feathers. Dwarf cassowaries have no natural predators; dogs, pigs, and humans are not endemic to New Guinea.
Known Predators:
Little is known about the mating system of Casuarius bennetti. However, more research has been completed on a related species, Casuarius casuarius, commonly known as southern cassowaries. Female southern cassowaries will become more tolerant of males as the breeding season approaches. Eventually, pairs of male and female cassowaries will form. When the female is ready to lay eggs, the pair will find a nesting site. The male will dance around the female in circles while his throat trembles and swells and he emits a series of low booming calls. Finally, the male will lead the female a short distance from the nest where the female will squat and allow the male to mount her. The eggs will be laid shortly after copulation. In captivity, C. casuarius has been known to copulate between the laying of each egg. After the eggs have been laid, the female will leave to mate with other males.
Mating System: polyandrous
In the genus Casuarius, the breeding season begins in May or June and lasts until October or November. Breeding is an annual occurrence. Females may mate with more than one male during a season and must be healthy and well-nourished in order to lay multiple clutches of eggs. The clutch size of dwarf cassowaries is between 4 and 6 eggs. The incubation period lasts between 49 and 52 days. Young become independent in 7 to 16 months and sexually mature at around 4 years old.
Breeding interval: In the genus Casuarius females generally breed 1 to 3 times during an annual breeding season.
Breeding season: The breeding season for Casuarius begins in May or June and lasts until October or November.
Range eggs per season: 4 to 6.
Range time to hatching: 49 to 52 days.
Average fledging age: 9 months.
Range time to independence: 7 to 16 months.
Average age at sexual or reproductive maturity (female): 4 years.
Average age at sexual or reproductive maturity (male): 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
In the genus Casuarius, mating with males and laying eggs are the only responsibilities of the female birds with regard to reproduction. Once the female has laid a clutch of eggs, she will move on to find another male with which she can mate. The eggs are incubated by the male, who is also responsible for raising and defending the chicks. The chicks will follow their father but are responsible for feeding themselves. Young fledge after about nine months and are driven out of the home range of their father.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male); pre-weaning/fledging (Protecting: Male); pre-independence (Protecting: Male)
