As tall as a person, with a high helmet on its head, a vivid blue neck and long drooping red wattles—the southern cassowary is found only in the tropical rainforests of north-east Queensland, Papua New Guinea and some surrounding islands.
In Australia the southern cassowary is found in far north Queensland's tropical rainforests, melaleuca swamps and mangrove forests.
Did you know?
The southern cassowary is Australia's heaviest flightless bird, but the emu is taller.
The southern cassowary is an important rainforest gardener, spreading the seeds of rainforest trees. Sometimes the seeds are so large that no other animal can swallow and disperse them.
Southern cassowary dung contains hundreds of seeds gathered over large areas of forest.
Common name: southern cassowary
Species name: Casuarius casuarius johnsonii
Family: Casuariidae (cassowaries and emus)
Of three species of cassowaries in the world, only the southern cassowary, Casuarius casuarius johnsonii, is found in Australia. Like the emu and ostrich, the southern cassowary is a ratite, a large flightless bird with unusual feathers and other features that distinguish it from all other birds. A striking bird with glossy black plumage, the adult southern cassowary has a tall, brown casque (helmet) on top of its head, a vivid blue and purple neck, long drooping red wattles and amber eyes. The purpose of the tall helmet or casque is unknown but it may indicate dominance and age, as it continues to grow throughout life. Recent research indicates it may also assist cassowaries in "hearing" the low vibrating sound made by other cassowaries. The casque is spongy inside, rather than bony, and may also act as a shock-absorber that protects the bird’s head when it pushes through dense thickets of rainforest and scrub.
The southern cassowary has coarse hair-like feathers with no barbules, and also lacks tail feathers. Its wing stubs carry a small number of long, modified quills which curve around the body. Each heavy, well-muscled leg has three toes, with the inside toe bearing a large dagger-shaped claw (up to 120 mm long) used for scratching and fighting other birds.
Newly-hatched chicks are striped dark brown and creamy white. After three to six months the stripes fade and the plumage changes to brown. As the young mature, the plumage darkens, the wattles and casque develop and the skin colour on the neck and wattles brighten. Cassowaries reach maturity at about three years of age.
Adult cassowaries can grow to an imposing 2 m tall. In general, the sexes are fairly similar in appearance, though females are slightly larger and can weigh up to 76 kg. Males can weigh up to 55 kg.
Habitat and distribution
At the time of European settlement of Australia, the southern cassowary lived in tropical rainforests of north-east Queensland, from Paluma Range (north of Townsville) to the tip of Cape York. Cassowaries are now found in three broad populations. One population in the Wet Tropics and two populations in Cape York.
On Cape York, they now occur in two separate populations: a southern population in the vine forests of the McIlwraith and Iron ranges and a northern population in the less extensive vine forests north of Shelburne Bay.
In the Wet Tropics cassowaries are distributed widely from Cooktown to Paluma Range. Approximately 89% of their remaining essential habitat in the Wet Tropics lies within protected tenures. Southern cassowary habitat in the Wet Tropics have been greatly reduced by land clearing and, cassowary numbers have also decreased.
Cassowaries require a high diversity of fruiting trees to provide a year-round supply of fleshy fruits. Although occurring primarily in rainforest, they also use woodlands, melaleuca swamps, mangroves and even beaches, both as intermittent food sources and as connecting habitat between more suitable sites. Places with a mix of these environments are preferred by cassowaries that live near the coast.
Cassowaries prefer fallen fruit, but will eat small vertebrates, invertebrates, fungi, carrion and plants. Over 238 species of plants have been recorded in the southern cassowary diet.
Cassowaries play an important role in maintaining the diversity of rainforest trees. Cassowaries are one of only a few frugivores (fruit eaters) that can disperse large rainforest fruits, and the only species that can carry large seeded fruits over long distances.
They swallow the fruit whole, digesting the pulp and passing the seeds unharmed in large piles of dung, distributing them over large areas throughout the rainforest. Some rainforest seeds even require the southern cassowary digestive process to help them germinate. Southern cassowary scats are large and often containing hundreds, if not thousands of seeds. A ready-made fertiliser, the dung helps many kinds of seed to grow. White-tailed rats, bush rats, melomys and musky rat-kangaroos sometimes feed on seeds in southern cassowary droppings, helping to further distribute the seeds.
Life history and behaviour
Usually solitary animals, cassowaries live in a home range that fluctuates depending on season and availability of food. The size of observed home ranges have varied between 0.52 km2 to 2.35 km2. The home range of a female southern cassowary usually overlaps with the home ranges of several males. Cassowaries are territorial, and contact between adults generally only occurs during mating. From May to November, pairs of cassowaries court briefly, mate and then separate. A female can mate with several males in one season.
Females lay between three to five large, olive-green eggs, generally between June and October. Eggs are incubated by the male for about 50 days, who guards the eggs and raises the chicks. Juveniles begin to fend for themselves from about eight to 18 months of age, when they are chased away by the male.
A number of factors affect southern cassowary survival. The major threats include the loss, fragmentation and modification of habitat, vehicle strikes, dog attacks, human interactions, pigs, disease and natural catastrophic events.
Southern cassowary habitat, particularly on the coastal lowlands, has been seriously reduced by land clearing for farming, urban settlement and other development. Urban development continues to threaten the populations that occur outside protected areas.
In the Mission Beach area, road accidents are the greatest single cause of southern cassowary death. Roads cut through southern cassowary territories, making it necessary for the birds to travel across them when looking for food. Birds can also be attracted to roads by people feeding them or throwing litter from vehicles.
Unrestrained and wild dogs are another major cause of southern cassowary mortalitu, particularly in areas near residential development. Chicks and sub-adults are small enough to be killed by dogs and packs of dogs also kill adult birds, pursuing them until they are exhausted, then attacking them. Dogs also indirectly affect cassowaries through their very presence, influencing the feeding, movements and general behaviour of the birds. Domestic dogs can also attack and kill cassowaries when they wander into suburban areas seeking food or water.
Pigs cause disturbance to the rainforest and compete with cassowaries for fallen fruit. They may also eat southern cassowary eggs and destroy nests. Pig control activities may also be hazardous to cassowaries, particularly when dogs are let loose to hunt pigs, and end up finding and attacking cassowaries instead.
Hand-feeding of cassowaries is a risk to both birds and people. Wild cassowaries conditioned to human food sources can be aggressive when protecting themselves or their chicks, or seeking other human food. As birds become less wary of humans, they may become more vulnerable to dog attack and road mortality as they search for food.
In recent years, cyclones have damaged large areas of southern cassowary habitat, causing temporary food shortages. This may place further stress on local populations already under threat from habitat fragmentation, dogs and vehicle strikes.
The Recovery plan for the southern cassowary Casuarius casuarius johnsonii sets out actions to secure the long-term protection of the southern cassowary through improved habitat protection and enhancement, threat abatement and community engagement programs.
Local residents in southern cassowary areas are establishing nurseries of southern cassowary food plants to revegetate southern cassowary habitat on cleared land, and create corridors between existing patches of habitat.
The Department of Environment and Science has mapped the habitat of the southern cassowary. This information can then be considered when assessing future developments by state and local governments to protect southern cassowary habitat.
A method for estimating southern cassowary abundance from genetic material in southern cassowary scats is being developed by the CSIRO. Recent work has shown that cells from the stomach lining of cassowaries are passed out in their scats, and collection and analysis of these scats, it may be possible to identify the sex and genetic code of each bird. These results may help to estimate the size of populations, as well as how far birds move and their breeding patterns.
How can you help cassowaries?
Everyone can help protect our remaining cassowaries. If you live in or visit southern cassowary territory, follow these tips:
- Leave vegetation on your property, especially in gully heads and along creek banks, as feeding grounds and corridors for cassowaries.
- Be careful when driving. Slow down to avoid hitting any animals and don't stop to watch them.
- Restrain your dog, especially when cassowaries are around.
- Never feed cassowaries, especially on the side of the road where they might get hit by passing cars.
- Let cassowaries find their own food. If you feed them, they may come to depend on you, their health will suffer and they may starve when you go away or move elsewhere. It may also make them aggressive towards other people.
- Plant southern cassowary food plants. The Cassowary Recovery Team can provide advice about the best trees to plant.
- If you would like to make a commitment to protecting southern cassowary habitat on your property, contact the department and ask about the nature refuges program.
Cassowaries are not common and may be hard to find. For such big, colourful birds, they blend remarkably well into rainforest shadows.
Look for signs such as characteristic large dung piles, full of seeds, scattered on the rainforest floor (often on walking tracks), and the large three-toed footprint (up to 180 mm). Listen for a deep rumbling sound which the bird makes to advertise its presence and respond to danger.
You're most likely to see cassowaries around Mission Beach. You might also see them at the Wallaman Falls Section of Girringun National Park, the Cape Tribulation Section of Daintree National Park, the Palmerston Section of Wooroonooran National Park and around Kuranda.
Cassowaries can be aggressive. Protect yourself by learning some simple safety tips. Be Cass-o-wary.
Southern cassowary behaviour is unpredictable. Cassowaries can inflict serious injuries to people and pets by kicking with their large clawed feet.
- Never approach cassowaries.
- Never approach chicks - male cassowaries will defend them.
- Never feed cassowaries - it is illegal, dangerous and has caused southern cassowary deaths.
- Always discard food scraps in closed bins and ensure compost bins have secure lids.
- Always slow down when driving in southern cassowary territory.
- Never stop your vehicle to look at southern cassowaries on the road.
- Keep dogs behind fences or on a leash.
If you come face-to-face with an aggressive bird, it's important to have some simple strategies to protect yourself. If you encounter a southern cassowary, back away slowly and put something like a tree or a backpack between yourself and the bird, and let it go on its way.
To report a southern cassowary sighting call 1300 130 372.
Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) 2012. Casuarius casuarius johnsonii in Species Profile and Threats Database. DSEWPaC, Canberra.
Department of the Environment, Water, Heritage and the Arts. 2009. Significant Impact Guidelines for the endangered southern cassowary (Casuarius casuarius johnsonii) Wet Tropics Population. EPBC Act policy statement 3.15 Department of the Environment, Water, Heritage and the Arts, Canberra.
Latch, P 2007. National recovery plan for the southern cassowary Casuarius casuarius johnsonii. Report to the Department of the Environment, Water, Heritage and the Arts, Canberra.
Environmental Protection Agency. Brisbane. http://www.environment.gov.au/system/files/resources/79235f07-9c32-45fa-b868-eb248691e945/files/sth-cassowary.pdf
Morcombe, M 2003, Field guide to Australian birds (Revised edition), Archerfield, Steve Parish Publishing Pty Ltd.