Double-wattled cassowary, Australian cassowary, Two-wattled cassowary
The Southern cassowary (Casuarius casuarius) is a large flightless bird closely related to the emu, ostriches, rheas and kiwis. It looks somewhat like a huge prehistoric turkey on stilts, wearing a large pointed casque or helmet. It is the second biggest bird on Earth alive today. Its name is from a Papuan word meaning ‘horned head’, a reference to the helmet made of tough skin on the top of its head. This casque slopes backward and the bird uses it to push through vegetation when running through the rainforest, head down. Its 'helmet' also reflects dominance and age.
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 sexes look alike, but the female is dominant and larger with a longer casque, larger bill, and brighter-colored bare parts. The juveniles have brown longitudinal striped plumage.
Southern cassowaries occur in New Guinea and Queensland, Australia. This bird lives in rainforests, although it can also be found in nearby mangroves, savanna, and sometimes in fruit plantations.
Southern cassowaries are not able to fly, having very small wings. Instead, they use their strong legs for mobility and to defend themselves. They are almost silent when walking slowly through the forest. If they are alarmed, they can crash through the forest at nearly 50 kilometers per hour, pushing vegetation out of their way with the bony casques on their heads. These birds are diurnal, they rest during the middle of the day, mainly foraging in the morning and late afternoon. They swim well and are good jumpers. This species is shy and solitary but can be aggressive, occasionally attacking humans, lashing out with their powerful legs and large claws. Being solitary, they have a home range which they defend against other cassowaries. While in the forest, they make a very loud, deep territorial roar which is able to be heard by others from a significant distance away.
Southern cassowaries are herbivores (frugivores), they mainly eat fallen fruits, and they also consume invertebrates, small vertebrates, and carrion.
These birds are polyandrous; a female mates with more than one male, and disappears straight after she has laid the eggs, starting a new nest each time. Courtship by the male consists of calling “boo-boo-boo” while inflating his throat. The breeding season in New Guinea begins when the dry season finishes and runs from June until October in Queensland. Nests are shallow depressions scraped in the ground, lined with leaves and grasses, and very well camouflaged amongst the vegetation. Several clutches of 3-5 greenish eggs may be laid during the breeding season. Incubation is by the male and lasts about 50 days. Chicks remain with their father for about nine months until they become independent. Southern cassowaries are reproductively mature at about three years old.
The destruction of tropical wet coastal lowland habitats and rainforests is the most important threat to the Southern cassowary population. The forest is cleared for agriculture and development, causing populations to become isolated and fragmented, reducing genetic variation. These birds also may not have access in their forest patches to sufficient food or water. Traffic accidents also kill many of these birds, particularly in Queensland, where more humans are coming to live. Humans also bring dogs, which prey particularly on young birds. Some communities in New Guinea rely on cassowaries as a food source and so heavily hunt these birds.
According to the IUCN Red List, the total Southern cassowary population size is 20,000-49,000 mature individuals. Currently, Southern cassowaries are classified as Least Concern (LC) on the IUCN Red List but their numbers today are decreasing.
The main role of the Southern cassowaries in the ecosystem where they live is to disperse seeds of fruits they consume in their diet.
