Cassowary

Cassowaries are large, flightless birds that belong to the genus Casuarius. They live in the tropical forests of New Guinea, the Moluccas, and northeastern Australia. These birds are part of a group called ratites, which also includes ostriches and emus, and they do not have a special bone feature that helps birds fly.

There are three types of cassowaries that are still alive today. The southern cassowary is one of the tallest and heaviest birds in the world, though it is smaller than ostriches and emus. The northern cassowary was found more recently and is in danger of disappearing. There was also an extinct type called the pygmy cassowary.

Even though cassowaries are usually very careful around humans, they can become very aggressive if threatened. They are known to attack dogs and people and are sometimes called the world's most dangerous bird. However, when looking at numbers, another bird, the common ostrich, causes more harm each year in South Africa.

Taxonomy, systematics, and evolution

The group of birds called cassowaries was first given its name by a French scientist in 1760. They belong to a special group of birds called ratites, which also includes emus, rheas, ostriches, kiwis, and some birds that lived long ago.

Scientists sometimes talk about different types of cassowaries, but deciding which ones are separate types can be tricky because of changes in the birds as they grow and because of limited examples to study. We still have much to learn about how cassowaries evolved and are related to other birds.

Description

Cassowaries are shy birds that live deep in the forest. They are very good at hiding before a person even knows they are there. Females are bigger and more colorful than males. The southern cassowary, found in far north Queensland rain forests, can grow up to about 2 meters tall and weigh as much as 85 kilograms, though this is rare.

Cassowaries are considered the largest birds in Asia since the Arabian ostrich went extinct. They have special feathers without tail feathers or a preen gland. Their wings are small and stiff, and they lack a tongue. They have sharp claws on their feet, and the inner toe has a very long, sharp claw that can kick humans and other animals. Cassowaries can run up to 50 kilometers per hour and jump up to 1.5 meters. They are also good swimmers.

All cassowaries have a special bony growth called a casque on their heads that grows as they age. In 2026, scientists found that these casques glow under ultraviolet light. The average cassowary lives about 18 to 20 years in the wild, but those in captivity can live up to 40 years.

Behaviour and ecology

Cassowaries usually live alone except when they are mating, laying eggs, or finding plenty of food. Males and females have their own areas to live in, which can overlap. Females sometimes move between areas but usually stay in the same place and mate with the same or similar males for their whole lives.

When cassowaries are ready to mate, the females make special sounds to start the process. Males run towards them, moving their heads in big ways. The females also drum on the ground. Sometimes, the female will step on the male’s back or chase him into the water, where they continue their mating rituals.

Both male and female cassowaries do not like others of the same sex around, but females may fight more than males. During mating season, they are less likely to fight each other.

Reproduction

The cassowary breeding season starts in May to June. Females lay three to eight large, bright green or pale green-blue eggs in a pile of leaves prepared by the male. These eggs are very big—only ostrich and emu eggs are larger.

The male takes care of the eggs for about 50–52 days, keeping them warm and safe. He also protects the baby chicks for about 9 months, keeping them safe from anything that might hurt them. The female does not help with the eggs or chicks. Instead, she lays eggs in other males’ nests. Baby cassowaries are brown with striped feathers. In New Guinea, young cassowaries are sometimes kept as pets until they grow up.

Diet

Cassowaries eat fruit from many different plants. Important fruits come from laurel, podocarp, palm, wild grape, nightshade, and myrtle plants. They can eat fruits with natural poisons because their digestive system is very short and simple, which helps them pass the seeds without harm. This helps spread seeds across the forest.

Cassowaries also eat each other’s droppings because they still contain useful bits of fruit. In cities, especially in Queensland, Australia, cassowaries have learned to eat food from picnics, tables, bird feeders, and compost piles. They also eat things they find, like building blocks, marbles, and small plastic toys.

In places where they are kept, cassowaries eat dog or monkey food and lots of fruit.

Role in seed dispersal and germination

Cassowaries help forests by eating fruit and spreading the seeds when they leave their droppings. They can carry seeds over long distances, which helps plants grow in new places. Seeds often grow better after passing through a cassowary’s body.

Threats

In New Guinea, cassowaries are large and strong birds with no natural enemies except humans. They are not often hunted because they are fast and can defend themselves. However, their baby chicks can be danger from large snakes, lizards, dogs, and eagles. Adult males protect their chicks fiercely.

In north-eastern Australia, cassowaries face dangers from vehicles and animals like wild boars and dogs, which can harm their eggs and chicks. This has caused their numbers to drop in some areas.

Distribution and habitat

Cassowaries live in the humid rainforests of New Guinea, nearby smaller islands, East Nusa Tenggara, the Maluku Islands, and northeastern Australia. They sometimes go into areas with palm scrub, grassland, savanna, and swamp forests.

People farming and cutting down forests have made it harder for cassowaries to live in some places. To help protect them, people are working to keep their homes safe and stop illegal hunting. In Indonesia, cassowaries are mainly found in the rainforests of Papua, especially in low and high areas. They also live in protected places like Wasur National Park in Merauke and Lorentz National Park, the largest national park in Southeast Asia. These birds help forests grow by spreading seeds, and you can sometimes see them in parks such as Mellwraith Range National Park, Paluma Range National Park, and Jardine National Park in Australia.

Status and conservation

The southern cassowary is considered endangered in Queensland. Scientists have found that only about 20-25% of the places where these birds used to live are still available. The main reason for this decline is that their homes are being lost or broken up.

People have studied why cassowaries sometimes die. Many are hit by cars, and others are attacked by dogs. Some die from diseases, while others are killed by people after attacking them. In some cases, the reason for their death is unknown.

Feeding cassowaries by hand can be dangerous because it brings them close to people, cars, and dogs. Wild pigs also threaten cassowaries by destroying their nests and competing for food.

In 2011, a big storm called Cyclone Yasi destroyed a lot of cassowary habitat, putting many birds at risk.

The town of Mission Beach in Queensland holds a festival each year to help protect cassowary habitats.

There are worries that cassowaries might cause problems if they were brought to the island of Tasmania. They could take food that other animals need, or compete with smaller animals for resources. However, because Tasmania does not have as many fruits as other places, cassowaries might also eat insects and small animals, which could affect other wildlife there.

In captivity

Cassowaries are usually alone and do not breed often in zoos compared to other birds like ostriches and emus. They live only in tropical rainforests, so their homes in zoos need to look like those forests. Cassowaries do not get along well with each other and need to be kept alone because they can be aggressive.

The double-wattled cassowary is the most common type in zoos and is known for its special look. As of 2019, only Weltvogelpark Walsrode in Germany has all three types of cassowaries in its collection. This includes the single-wattled cassowary and Bennett's cassowary.

Relationship with humans

Role in Papuan cultures and semi-domestication

People in New Guinea have lived with cassowaries for thousands of years. Some groups raise baby cassowaries like chickens, using them in special ceremonies or for food. These birds are the largest that people have ever kept as livestock and one of the oldest animals people have raised. Different cultures see cassowaries in unique ways. For example, some people think of them as family, not just animals.

Urbanisation of local cassowary population

In places where cities have grown, cassowaries still live, adapting to new surroundings. In areas like Queensland, Australia, and Port Moresby in Papua New Guinea, these birds now eat more fruits from plants that people grow, along with their usual foods. They also find food in gardens, picnic spots, and even eat scraps left by people. Because there is less forest and more people and cars, cassowaries in cities stay more active and move around a lot.

Attacks

Cassowaries can be dangerous because they have sharp claws on their feet. During World War II, soldiers were told to stay away from them. Some people have been hurt when cassowaries felt threatened, especially if they were trying to take food or protect their young. There have been a few serious incidents, but cassowaries usually do not attack unless they feel unsafe.