# Southern Cassowary (*Casuarius casuarius*)

> The southern cassowary is a large, flightless rainforest bird of Queensland and New Guinea, often called the world's most dangerous bird. It stands up to 1.8 m (6 ft) tall, weighs 40 to 60 kg (88 to 132 lb) and carries a dagger-like claw on each foot. It feeds mainly on fallen fruit and can sprint through dense forest at up to 50 km/h (31 mph). Though listed as Least Concern globally, its Australian population is under pressure, and wild birds live 30 to 40 years.

- **Category:** Bird
- **Conservation status (IUCN):** Least Concern
- **Range:** Tropical rainforest of northern Queensland, New Guinea, and Aru Islands — southern cassowary in Australia and New Guinea.
- **Canonical page:** https://globalanimalguide.org/animals/cassowary/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Aves
- **Order:** Casuariiformes
- **Family:** Casuariidae
- **Genus:** Casuarius

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Casuarius casuarius |
| Diet | Frugivore — rainforest fruit and fungi |
| Habitat | Tropical rainforest of Queensland and New Guinea |
| Lifespan | 30–40 years in the wild |
| Weight | 40–60 kg (88–132 lb); females larger and more colourful |
| Top speed | Up to 50 km/h (31 mph) through dense forest |
| Conservation status | Least Concern (IUCN) |

## A powerful and dangerous bird

The southern cassowary has earned a reputation as the most dangerous bird in the world, thanks to the long, dagger-like inner claw on each of its powerful feet. When cornered or defending chicks, it can deliver a forward kick strong enough to cause serious injury. Most attacks, however, involve birds that have been fed by people and have lost their natural wariness. Left alone in the forest, cassowaries are shy and prefer to avoid humans altogether.

## The rainforest gardener

As a frugivore, the cassowary lives almost entirely on fruit that has fallen to the rainforest floor, along with some fungi. It swallows large fruits whole and passes the seeds unharmed, spreading them far from the parent tree. Many rainforest plants have seeds so big that the cassowary is one of the only animals able to move them, making the bird vital to the forest's regeneration. Some tree species depend on it so heavily that they struggle to spread where cassowaries have vanished.

## Casque and appearance

The most striking feature of the cassowary is the tall, helmet-like casque on top of its head, made of a spongy material over a bony core. Its function is still debated, with theories ranging from a tool for pushing through undergrowth to a resonating chamber for deep calls. The bird's glossy black plumage contrasts with vivid blue and red skin on its bare neck and dangling wattles. Females are larger and more brightly coloured than males, the reverse of the pattern seen in many birds.

## Breeding and fatherhood

In the cassowary's world it is the male that raises the young. After a female lays a clutch of large green eggs, she leaves to mate with other males, and the father takes over completely. He incubates the eggs for about 50 days, barely eating, then guards and leads the striped chicks for up to nine months. During this time the normally solitary male becomes fiercely protective and will charge anything that threatens his brood.

## Speed and movement

Despite its bulk, the cassowary is remarkably fast and agile in thick forest. It can run at up to 50 km/h (31 mph), weaving between trees, and is also a capable jumper and a strong swimmer. When threatened it usually flees rather than fights, crashing through dense undergrowth that would stop a person. Its stout, three-toed feet give it both the traction to sprint and the weaponry to defend itself.

## Conservation and threats

Globally the southern cassowary is listed as Least Concern by the IUCN, but its situation in Australia is far more precarious. Clearing of tropical rainforest, collisions with vehicles, dog attacks and feeding by tourists all threaten the northern Queensland population. Because the species reproduces slowly and needs large tracts of connected forest, local declines are hard to reverse. Protecting rainforest corridors and keeping wild birds from becoming used to people are key to their future in Australia.

## Frequently asked questions

### Why is the cassowary called the most dangerous bird?

The cassowary has a long, dagger-like claw on the inner toe of each foot and can deliver a powerful kick. It earns the title because a defensive cassowary can seriously injure a person, though attacks are rare and usually involve birds fed by humans.

### How big is a southern cassowary?

Southern cassowaries stand up to 1.8 m (6 ft) tall and weigh between 40 and 60 kg (88 to 132 lb). Females are noticeably larger and more brightly coloured than males.

### What do cassowaries eat?

Cassowaries are frugivores that feed mainly on fruit fallen to the rainforest floor, along with some fungi. By swallowing large fruits whole and passing the seeds, they play a vital role in spreading rainforest plants.

### How fast can a cassowary run?

A cassowary can run at up to 50 km/h (31 mph) even through dense forest. It is also an agile jumper and a strong swimmer, and usually chooses to flee rather than fight.

### What is the casque on a cassowary's head for?

The tall, helmet-like casque is made of spongy tissue over bone, and its exact purpose is still uncertain. Suggested roles include pushing through undergrowth, signalling to other cassowaries, and helping the bird produce its deep, booming calls.

### Are cassowaries endangered?

The southern cassowary is listed as Least Concern by the IUCN overall, but its Australian population is threatened. Rainforest clearing, vehicle collisions and dog attacks are the main dangers in northern Queensland.

## Sources

- [IUCN Red List — Casuarius casuarius.](https://www.iucnredlist.org/search?query=Casuarius%20casuarius&searchType=species)
- [Animal Diversity Web — Casuarius casuarius. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Casuarius_casuarius/)

---
Source: Global Animal Guide (https://globalanimalguide.org/animals/cassowary/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.