Common Name: Cassowary
Scientific Name: Casuarius spp.
Cassowaries are fascinating, giant birds found in the tropical forests of New Guinea, nearby islands, and northern Australia. Three species exist: the southern cassowary, the northern cassowary, and the dwarf cassowary. Among these, the southern cassowary is the most common. It ranks as the third-tallest and second-heaviest bird, just after the ostrich and emu.
These birds are known for their vivid blue and black plumage and helmet-like casques on their heads. Although they are visually striking, cassowaries have a fearsome reputation. When threatened, they can inflict serious injuries with their powerful legs and sharp claws.
Description
Cassowaries are large, flightless birds with a noticeable appearance. Their glossy black feathers contrast vividly with their blue and purple necks. Red wattles hang from their necks, adding to their colourful display.
A standout feature of the cassowary is the casque on its head. This helmet-like structure gives the bird a prehistoric look. Females are larger than males, often reaching up to 2 metres in height and weighing around 70 kg. Males, while slightly smaller, are still impressive.
Cassowary feathers are distinctive. They have a shaft and loose barbules, but lack tail feathers or a preen gland. Their small wings feature five or six large remiges, which are reduced to stiff quills. These adaptations, along with their wedge-shaped bodies, allow them to move swiftly through dense rainforests. They also have no tongue and possess robust, pointed beaks ideal for picking up fruit and small animals.
Their three-toed feet include a long, dagger-like claw on the inner toe. This claw is a formidable weapon when the bird feels threatened.
Cassowaries' physical traits go beyond appearance. The casque may aid in communication, while their neck colours and wattles help attract mates and establish dominance.
Habitat
Cassowaries thrive in the humid rainforests of New Guinea, East Nusa Tenggara, the Maluku Islands, and northeastern Australia. They prefer lush, dense rainforests but are also found in palm scrubs, grasslands, savannahs, and swamp forests. In Australia, they may be spotted in national parks such as Mellwraith Range, Paluma Range, and Jardine National Park.
There is debate about cassowaries on some islands, with uncertainty over whether these populations are naturally occurring or have been introduced by humans. Cassowaries avoid open areas and depend on the shelter and resources provided by their preferred environments.
Diet
Cassowaries primarily feed on a variety of fruits, which constitute the bulk of their diet. Their love for fruit is clear as they swallow it whole. This behaviour aids in seed dispersal, helping with forest regeneration.
When fruits are scarce, cassowaries switch to a more varied diet. They hunt small animals and scavenge for carrion. Their opportunistic feeding habits enable them to make the most of available food sources.
Unique to their diet is the ability to ingest large fruits in a single bite. This allows them to distribute seeds far and wide, supporting plant growth and enhancing biodiversity.
Behaviour
Cassowaries are generally solitary, interacting mainly during courtship, egg-laying, or when food is plentiful. Each male and female controls their territory, which can span up to 3 square kilometres.
Territories may overlap, but females typically remain in the same areas, often mating with the same males or nearby ones throughout their lives.
Courtship begins with the female’s low-frequency calls. Males respond with dramatic head movements and neck displays. This ritual may involve the female approaching the male, stepping on his back, or engaging in a chase that ends in water.
During these chases, both birds may copulate for extended periods of time. Territorial disputes, especially among females, are common but tend to ease during the mating season.
Conservation Status
The southern cassowary is struggling to survive. Despite being listed as "least concern" on the IUCN Red List, its habitat in Queensland has dramatically shrunk, leaving just 20-25% of its original range. Motor-vehicle strikes are a major threat, with these accidents causing over half of the recorded cassowary deaths. Dog attacks and hunting also contribute to their decline.
Hand feeding in tourist areas worsens the situation, attracting cassowaries to dangerous suburban zones where they face increased risks from cars and dogs. Additionally, feral pigs destroy nests and compete for food, especially during times of scarcity.
Cyclone Yasi in 2011 severely impacted about 10% of the Australian cassowary population. While organisations like the Cassowary Recovery Team are working to protect these birds, there are growing concerns about their potential impact as an invasive species in Tasmania, where they could disrupt local wildlife and food chains.
Despite the dramatic stories about these birds, cassowaries face far greater threats from humans than the other way around.
Fun Facts
Here are some fantastic facts about cassowaries:
Largest Vertebrate: They're the largest native vertebrate in Australian rainforests.
Heaviest Bird: The second-heaviest bird in the world, after the ostrich.
Tallest Bird: Third tallest bird globally, following the ostrich and emu.
Biggest Egg: The cassowary egg is the third largest of all birds, weighing about 584 g.
No Tongue: Cassowaries lack a tongue and use their beaks to handle food.
Casque: Their casque might amplify sounds or act as a shock-absorber, and it might also indicate dominance.
Speed & Agility: They can run up to 50 km/h, jump 1.5 metres, and swim effectively.
Unique Plumage: Their feathers are black and fur-like, with bright blue and red skin.
Diet: They mainly eat fruits, snails, fungi, and occasionally small mammals and birds.
Similar Species
The emu, native to Australia, bears a resemblance to the cassowary but differs in several key ways. Unlike the cassowary, which boasts a vibrant casque and vivid neck colours, the emu has a more subdued appearance. It lacks the blue helmet and sharp claws found on the cassowary. Emus are also lighter, weighing about half as much as ostriches. Their strong legs are used for running and swimming rather than the defensive kicks seen in cassowaries.
The ostrich, the world’s largest bird, contrasts with the cassowary in both habitat and appearance. While ostriches inhabit open savannahs, cassowaries thrive in dense forests. The cassowary’s casque may function for thermal regulation or display, distinguishing it from the emu’s simpler, sleeker profile.
Other ratites include the rhea from South America and the kiwi from New Zealand. Despite their size differences, these birds share a common ancestry and adaptations similar to those of their environments.
