The World's Most Dangerous Bird and 9 Runners-up

The northern cassowary, or single wattled cassowary, is often considered the deadliest bird on the planet, especially when protecting cassowary chicks.

Over 150 attacks have been reported from the norther cassowary since 1900. However, of these numerous cassowary attacks, only one has led to a human death in the wild.

These large, flightless birds have powerful legs with sharp, dagger-like claws that they use to defend themselves when threatened.

Known for their solitary nature, female cassowaries are particularly aggressive when guarding their young or defending their territory. The rainforests of New Guinea serve as the primary cassowary habitat.

Coming in as a close second, the southern cassowary — also known as the double wattled cassowary — is another member of this family of exceptionally large birds. This flightless bird is known for its territorial behavior and aggressive nature.

This cassowary is native to the rainforests of northern Australia and New Guinea, where it feeds on fruit, including the rare Australian rainforest tree fruits.

Southern cassowaries are the most common cassowary species. Like the others, they are also equipped with strong legs and sharp claws, which they use to kick and slash at threats, making them one of the most dangerous birds you could encounter in the wild.

Long story short: You don't want to just drop in on a wild cassowary population unless you have a death wish.

While smaller than its northern and southern relatives, the dwarf cassowary is still one of the deadliest birds.

Native to New Guinea and surrounding islands, these solitary birds can be highly territorial. Though less aggressive than the their larger counterparts, they are still capable of delivering powerful kicks with their sharp claws.

Dwarf cassowaries are also highly protective of their young, and a defensive mother is not a bird you want to cross.

The ostrich may look like a big, goofy bird, but don't let that fool you; these giants can be dangerous. Standing up to 9 feet (2.7 meters) tall and weighing over 300 pounds (136.1 kg), ostriches have powerful legs and sharp claws that can deliver fatal kicks to predators or humans.

Ostriches are the largest bird species living today, and while they prefer to run from danger (and they can run fast — up to 45 miles (72 km) per hour!), they will fight back fiercely if cornered.

Like the ostrich, the emu is a large flightless bird known for its speed and strength. Native to Australia, these birds can become aggressive if provoked or if their young are threatened.

Emus are equipped with sharp talons and strong legs that allow them to deliver powerful kicks. Although emus are generally shy, they are capable of inflicting serious injuries when they feel threatened.

The harpy eagle is one of the largest and most powerful birds of prey in the world, and it has the strength to back up its reputation. Native to the rainforests of Central and South America, harpy eagles use their massive talons — up to 5 inches (13 cm) long — to catch and kill prey as large as monkeys and sloths.

While they don't typically pose a threat to humans, their sheer power makes them one of the most dangerous birds in the avian world.

The lammergeier, also known as the bearded vulture, has a strange diet that consists mainly of bones. This bird is known for picking up bones and dropping them from great heights to break them into smaller, more digestible pieces.

While lammergeiers aren't generally aggressive toward humans, they are territorial and may strike down on other species that wander to close too their nest.

These massive birds have wingspans up to 9 feet (2.7 meters), making them a formidable sight in their natural habitat in mountainous regions of Europe, Africa and Asia.

The red-tailed hawk is one of North America's most common birds of prey, and while it usually hunts small animals like rodents, it can be quite dangerous if threatened. With sharp talons and a strong beak, these hawks can cause significant injury if they feel the need to defend their territory or nest.

Attacks on humans are rare, but the strength of the red-tailed hawk makes it one of the more dangerous birds to approach without caution. Very rarely, the bird of prey may try to dive-bomb small dog or cat breeds that are left unattended in hawk territory.

Known as the "tiger of the sky," the great horned owl is a fierce predator with a powerful grip and razor-sharp talons that it can use to take down ground-dwelling animals and even other birds of prey.

These owls are extremely territorial and will defend their nests aggressively, sometimes attacking humans who get too close. With their stealthy flying abilities and strong beaks, great horned owls can cause significant injuries, particularly to anyone unknowingly venturing into their nesting area.

The barred owl might not look particularly threatening, but it has been involved in several aggressive encounters with humans. These owls are extremely territorial and have been known to swoop down and attack hikers or anyone who gets too close to their nests.

Though they are smaller than some other birds of prey, barred owls can still inflict painful wounds with their talons and beak.

We created this article in conjunction with AI technology, then made sure it was edited and fact-checked by a HowStuffWorks editor.