There are nearly 10,000 different species of bird in the world as recorded. Birds’ diverse forms and extraordinary adaptions have fascinated human passion for centuries. Some stand out for their sheer size, commanding attention and awe.
In this list, we present the top 10 largest flying birds in the world, which are considered wingspan. For this piece, it makes sense to consider the biggest birds by their reliable mass and weight.
Meanwhile, the heaviest birds, with much denser bones and bodies, are almost flightless.
1. Common Ostrich
The common ostrich is known as the largest living bird on the planet, with its weigh 157 kg / 346 lb. They can tower up to 9.8 feet (3 meters) tall and weigh up to an astonishing 346 pounds (157 kilograms).
Ostrich possesses long, powerful legs that allow them to race at amazing speeds, reaching up to 43 miles per hour (70 kilometres per hour).
2. Somali Ostrich
The Somali ostrich weighs 130 kg / 290 lb and was once considered a subspecies, the Somali ostrich is now recognized as a distinct species, found in the Horn of Africa.
They have a height of up to 9.8 feet (3 meters) and a weight of around 290 pounds (130 kilograms), these ostriches are huge. Their powerful legs allow them to cover great distances with remarkable speed.
In addition, the skin of the Somali ostrich’s neck and thighs is blue (rather than pinkish), becoming vivid blue on the male during mating season which makes it otherwise identical to other species of ostriches.
3. Southern Cassowary
Weighing 85kg / 187 lb and height of 5.8 feet (1.8 meters) truly, they command attention and awe. They have a horn-like brown casque on the top of their head and lethal dagger-like claws on their toes. They have a reputation for being aggressive and can jump and kick with force.
4. Northern Cassowary
They weigh 75kg / 167 lb. The northern cassowary is a stocky bird of northern New Guinea. These birds are 149 cm (4 ft 10) long and 1.5-1.8 m (4 ft 11 in – 5 ft 11 in) tall. They are typically shy and solitary and will diet on berries, fruit, small animals and insects.
The northern cassowary has a shorter bill than the southern cassowary, measuring 12 to 13.7 cm (4.7 to 5.4 in), but a slightly larger tarsal length, measuring 28 to 33.2 cm (11.0 to 13.1 in).
5. Emperor Penguin
These magnificent creatures have a height of 4 feet (1.2 meters) and weigh around 88 pounds (40 kilograms), but can grow larger. They are well adjusted to survive the severe cold, forming huddles to withstand the freezing temperatures that can plummet as low as -40 degrees Celsius.
With their weight being 46kg / 101 lb, another interesting fact about them is that they can hold their breath for 22 minutes.
6. Greater Rhea
The Greater Rhea is the largest bird native to South America. These elegant giants can stand up to 5.9 feet (1.8 meters) tall and weigh up to 88 pounds (40 kilograms). With their long legs and strong bodies, rheas can reach impressive speeds of up to 37 miles per hour (60 kilometres per hour) when running.
7. Emu
Emus are tall birds with long necks and legs endemic to Australia. They are the second-tallest living birds that can reach up to 1.9 metres (6 ft 3 in) in height.
Adult emus weigh between 18 and 70 kg (40 and 150 lb) and can run at high speeds of up to 48 km/h (30 mph), due to their highly specialised pelvic limb musculature.
When running at full speed they can take long strides of up to 9 feet at a time.
8. Dwarf Cassowary
The dwarf cassowary weighs 34 kg / 74 lb. They live in the mountain forests of New Guinea, New Britain, and Yapen Island. They are amusingly named ‘dwarf’ as they are the smallest species of cassowary, and yet – they still make the top 10 list of largest birds in the world.
They gauge between 3ft 3 – 4ft 11 in length and can weigh between 7.6 and 34 kg (39 and 75 lb). The dwarf cassowary primarily feeds on fallen fruit, but will also eat small vertebrates, insects and fungi.
9. King Penguin
This is the second-largest species of penguin weighing 20kg / 44 lb. They are found in the subantarctic regions, these aquatic birds reach heights of around 3.1 feet (0.95 meters).
King penguins display a unique black and white plumage. They have bright orange patches on their necks, beaks, and cheeks. Remarkably, they can dive to depths of 300m (1,000 ft) in search of fish, squid and krill.
10. Lesser Rhea
The lesser rhea is a large, flightless bird that lives in the open scrub and grasslands in Altiplano, and Patagonia, in South America. They are the smaller of the two species of rheas but can stand up to 100cm (1 meter) in height and weigh between 15 to 29 kg (33–64 lb).
The lesser rhea has incredibly sharp claws on its toes and can reach lightning-running speeds of 60 km/h (37 mph) to escape predators.
