The World’s Biggest Birds: Meet the Feathered Giants

When we think of large birds, we might picture swans, ostriches, or eagles. But which bird is the biggest? Well, it depends on what you mean by big! When considering the “biggest” bird species, different measurements can be used, such as wingspan, height, or weight. Therefore, the title of the largest bird may vary depending on the type of measurement used.

1. Wandering Albatross – largest wingspan

The Wandering Albatross (Diomedea exulans) is a magnificent and iconic seabird known for its impressive size and remarkable long-distance flights across the open ocean. It is part of the Diomedeidae family, which includes several species of albatrosses but the Wandering Albatross is the largest of the species and is renowned for its graceful gliding ability. 

The Wandering Albatross has a wingspan that can reach up to 11.5 feet and it stands an impressive 3.5 feet tall. Its enormous wings provide incredible lift, allowing them to harness the power of the wind. The birds employ a technique called “dynamic soaring” to stay airborne for hours or even days without actually flapping their wings at all. This involves using the varying wind speeds near the ocean surface to gain lift and momentum. They glide downwind to gain speed, then turn into the wind to rise up, repeating this cycle to travel vast distances with minimal effort.  

The wings of the Wandering Albatross are an incredible natural feat of engineering. Long and narrow wings are very efficient as they minimize drag and maximize lift. This allows them to glide effortlessly, taking advantage of even the slightest air currents. Albatrosses also have a unique ability to lock their wings in place, allowing them to glide for extended periods without expending energy. This also enables them to sleep while flying! Some species of young albatross leave the nest and explore the oceans, only returning to land after 5 years!

Despite their large size, albatrosses have a lightweight skeleton with hollow bones, which reduces their overall weight and makes it easier to stay airborne. In essence, the Wandering Albatross is a living glider, perfectly engineered to exploit the power of the wind. 

Wandering Albatrosses are primarily scavengers, feeding on squid, fish, and krill, often by catching prey from the surface of the water while in flight. They also have a unique adaptation that allows them to drink seawater – they have a special gland located above their eyes that filters the salt, enabling them to excrete it through their nostrils.

2. Kori Bustard – heaviest flying bird

The Kori Bustard (Ardeotis kori) is a fascinating bird, and its weight is a main point of interest! Male birds can weigh up to a whopping 42 pounds! While other bustards might compete with the Kori, the nearest other heavy-flying bird species is the Mute Swan, weighing in at a paltry maximum of 26 pounds.    

Kori Bustards are found in grasslands and savannas across eastern and southern Africa where they roam, their strong legs being well-suited for walking and running.  They are omnivorous and will search for a variety of foods, including insects, small mammals, lizards, snakes, seeds, and berries. They’ve even been observed eating carrion. Being so heavy, it is understandable that they prefer to spend most of their time on the ground and their grayish-brown plumage, finely barred with black, provides excellent camouflage in their grassland habitat.  

Their overall size contributes significantly to their weight. To support their large bodies and powerful legs, they have a strong musculature. While large flying birds like the albatross generally have lightweight, hollow bones, the Kori Bustard’s bones have to be substantial enough to support its heavy weight. 

Essentially, the Kori Bustard’s weight is a combination of its large size, strong build, and a diet that supports its substantial frame. It’s a fascinating example of how evolution has shaped birds to thrive in their specific environments!

3. African Ostrich – tallest and heaviest flightless bird

The biggest bird species in terms of height and weight is the African Ostrich (Struthio camelus). Ostriches are native to Africa and are flightless. They are found in various regions across Africa, including savannas, grasslands, and semi-arid areas, including countries like South Africa, Namibia, Botswana, and others.

Adult male ostriches can reach a height of up to 9 feet. Female ostriches are slightly smaller, but still quite large compared to other birds. A significant portion of their height comes from their incredibly long neck, which allows them to reach high into trees for food and to spot predators from a distance. They also have very long legs which also contribute to their height and enable them to run at impressive speeds.

Male ostriches typically weigh between 220 to 287 pounds. However, some exceptionally large males can even reach weights of over 340 pounds! That is heavier than an average refrigerator.

Ostriches have large wings covered in soft, fluffy feathers that are used for display during courtship rituals but are not used for flight. The wingspan of an ostrich is an impressive 6.6 to 9.8 feet, and they don’t even fly! Instead, they are very fast runners and can reach speeds of up to 40 miles per hour, making them the fastest birds on land.

4. Dalmatian Pelican – heavy with a huge wingspan

The Dalmatian Pelican breeds in southeastern Europe and across parts of central Asia. Think of areas around the Black Sea, the Danube Delta, and eastward into countries like Kazakhstan, Russia, and Mongolia. During the winter months, they tend to move to warmer regions. European birds often head to the Mediterranean, while those from central Asia might go towards Iran, India, and even the east coast of China. Dalmatian Pelicans are strongly associated with freshwater habitats. Basically, they move around a lot and to do that, they need large, strong wings.    

So, here are the stats: the wingspan of this attractive waterbird can reach up to 11 feet, rivaling the wingspan of some albatrosses. It is also very heavy, weighing between 16 to 34 pounds. The question is, why? Why does it need to be so big and heavy? The answer is, of course, a combination of adaptations that make it well-suited for its specific environment and lifestyle.

Firstly, their large size is well-suited for their aquatic lifestyle. Their substantial bodies help them stay buoyant in the water, and their large, powerful wings allow them to take off from the water’s surface. Then we have hunting. Their large size, particularly their enormous bill and pouch, is incredibly useful for catching fish. The pouch acts like a net, allowing them to scoop up large quantities of fish and water. The bigger the pouch, the more fish they can catch at once.  

Being large can be advantageous for thermoregulation, especially in warmer climates. Their bulk helps them retain heat in cooler conditions and their large surface area allows them to dissipate heat in warmer conditions.

Over time, natural selection has favored larger individuals in this species. Larger pelicans may have had advantages in terms of hunting success, survival, and reproduction, leading to the evolution of their impressive size. Essentially, the Dalmatian Pelican’s large size It’s a great example of how evolution shapes animals to thrive in their niches!

5. Emu – tall, flightless, and fast!

Another notable large bird species is the Emu (Dromaius novaehollandiae), which is native to Australia. While not as tall as the ostrich, Emus can still reach a height of around 6.2 feet and weigh up to 120 pounds.

Despite having wings, Emus are flightless. Their wings are small and not strong enough to lift their heavy bodies. However, they have long legs that are well adapted for running and they can reach speeds of up to 50 km/h! They have three toes on each foot, with sharp claws that they use for defense.  

Emus are found in the wild only in Australia and inhabit a wide range of environments, including forests, woodlands, grasslands, and semi-arid regions. They are well-adapted to various habitats and can withstand extreme temperatures.

While the Emu might be in the mix for the tallest bird, they are also famous for their small brain, which is relatively small compared to their body size. It weighs less than an ounce and is roughly the size of a walnut. To put that in perspective, an African Ostrich, which is larger than an Emu, has a brain that weighs around 1.5 ounces. While Emus may not have the largest brains, they are still intelligent animals with complex behaviors. They are able to navigate their environment, find food, and raise their young in a range of habitats across the Australian landscape. 

6. Southern Cassowary – tall, heavy, and surprisingly agile

The Southern Cassowary (Casuarius casuarius) is a large and impressive bird! They can grow up to 6.6 feet tall. Unusually, females are generally larger and heavier than males. Females can weigh up to 167 pounds, while males can weigh up to 121 pounds. Native to Australia and Papua New Guinea, they are not generally as tall as Emu but are more solidly built, making them heavier. Their body shape is not only similar to the Emu but also to the Ostrich and Rhea.

Southern Cassowary are much more reticent than the other large, flightless birds on this list which has helped to give them a sort of mythical status. Outside of breeding time, they are generally alone, wandering their territory in the rainforest quietly and slowly. These ‘ghosts’ of the rainforest play a crucial part in its survival as they are responsible for dispersing the seeds of up to 100 native plants. Their size means they eat a lot and move around a lot and are considered the quiet hero of their habitat. 

Although it might seem like a large size would be a hindrance in dense vegetation, the Southern Cassowary are surprisingly agile. Their strong legs and bodies allow them to push through thick undergrowth, and their casque (the bony crest on their head) helps protect their head as they move through the forest.

7. Steller’s Sea-Eagle – large and powerful

The Steller’s Sea Eagle is a truly magnificent bird and definitely earns its place among the largest and most impressive eagles in the world. They actually claim the record for being the heaviest eagle species, with females reaching weights of up to 22 pounds! That’s seriously impressive. They also boast a wingspan that can reach up to 8 feet, giving them an incredible presence in the sky.   

This stunning bird of prey has a striking appearance with dark brown/black plumage, contrasting white shoulders and tail, and a massive, bright yellow beak. This makes them easily recognizable. They are found in coastal regions of northeastern Asia, including Russia, Japan, China, and Korea. They prefer habitats near large bodies of water, such as coastlines, rivers, and lakes.    

As their name suggests, Steller’s Sea Eagles are primarily fish eaters. They are incredibly skilled at catching fish, often diving into the water to grab their prey with their powerful talons. But, they are opportunistic hunters, taking advantage of whatever food sources are available. Besides fish, they will also prey on other water birds, small mammals, and even carrion.

Their large size and strength allow them to take down large prey and the large talons and powerful grip are essential for hauling large, slippery fish out of the water. The bigger the eagle, the bigger the fish it can carry! 

There are other essential reasons for the eagle being so huge. Firstly, living in cold, coastal regions, their large body mass helps them conserve heat and survive in harsh conditions. This is especially important during the winter months when food may be scarce. Their large size and imposing presence also help them defend their hunting grounds and nesting sites from rivals, ensuring access to resources for themselves and their offspring.

8. California Condor

The California Condor (Gymnogyps californianus) is a critically endangered species of vulture found in North America. It is one of the largest flying birds in the world with an impressive wingspan that can reach up to 9.5 feet across, making it one of the largest wingspans of any bird. They have a body length of about 3.3 to 4.5 feet and adult birds can weigh between 18 to 31 pounds.

These incredible birds have a distinctive appearance with black feathers on their bodies and wings, while their bare heads are mostly red or orange. They have a white triangular patch on the underside of their wings, which is visible during flight.

California Condors are scavengers, meaning they primarily feed on carrion and this may help explain why they need to be so big. Firstly, similar to the albatross, the large wingspan allows them to soar effortlessly for long periods, covering vast distances in search of food with minimal energy expenditure. Their gliding ability, combined with their incredible eyesight, allows them to find carcasses from great distances as they soar high above the ground. Once they find a carcass, they can outcompete other scavengers for access to it. No one is going to argue with a condor! 

They are nature’s cleanup crew, helping to prevent the spread of disease by consuming decaying remains.  

9. Northern Cassowary 

The Northern Cassowary (Casuarius unappendiculatus) is a large, flightless bird native to the lowland rainforests and coastal swamps of New Guinea and some nearby islands. They are one of the largest birds in the world, standing up to 6 feet tall and weighing up to 80 pounds. Females are typically larger than males.   

These rare and little-known birds are much more attractive than other similar birds like the Emu, ostrich, and rhea. Their bodies are covered in dense, shaggy black feathers that provide camouflage in the forest undergrowth. The bare, bright blue face contrasts with a vividly colored neck, which can be red or yellow, depending on the individual. On top of their head, they sport a prominent casque, a bony crest that acts like a helmet. The function of this casque is still not fully understood, but it might be used for attracting mates or for head protection.

Unlike the Southern Cassowary, the Northern Cassowary has a single wattle (a fleshy appendage) hanging from its throat. This is one of the key distinguishing features between the two species. They also have powerful legs with three toes, one of which has a long, sharp claw that can be used for defense.   

Like their southern cousins, these shy birds prefer dense, lowland rainforests, particularly near water sources like swamps and rivers where they search for a wide variety of fruits that have fallen from trees. They also supplement their diet with insects, small animals, and fungi.  

10. The Emperor Penguin

The Emperor Penguin (Aptenodytes forsteri) is the largest penguin species, and that’s not just a little bit big – they’re truly impressive in size! Standing tall at heights of around 3.6 to 4.3 feet, they are taller than many young children! These penguins are also very heavy. Adults can weigh anywhere from 49 to 99 pounds, though their weight fluctuates throughout the year depending on the breeding cycle and food availability. Males tend to be a bit heavier than females. Of course, the fact that the Emperor Penguin swims rather than flies means that it is advantageous to be heavy.   

Their impressive size actually helps them in a number of ways including insulation. Emperors are rarely seen outside of Antarctic waters and their bulk helps them conserve heat in the harsh environment. Their weight also allows them to store fat reserves, which are crucial for surviving the long breeding season when they can’t hunt.  

They also need that bulk during the breeding season when these interesting birds really become extraordinary. Unlike most bird species where the female does the majority of the incubation, in Emperor Penguins it’s the male who takes on this crucial responsibility. After the female lays a single egg, she carefully passes it to the male. This is a delicate process, as the egg can easily freeze or break. The male then places the egg on his feet and covers it with a loose fold of skin called the brood pouch. This pouch is located near his feet and is specially designed to keep the egg warm.   

The male incubates the egg for about 2 months and during this time, he stands on the ice, often in harsh winter conditions with temperatures plummeting to -76°F or lower, and strong winds. If he wasn’t so heavy, both the male and the egg or chick would surely perish. Emperor Penguins are truly giants among penguins, and their size is a key adaptation that allows them to thrive in the extreme conditions of Antarctica.

11. Greater Rhea

The Greater Rhea (Rhea americana) is a large, flightless bird native to South America. They can stand between 4.7 to 5.7 feet. They typically weigh between 44 to 60 pounds, however, males can be larger, sometimes reaching up to 88 pounds. Their size makes them the largest native bird in South America and one of the biggest birds in the world!

The Greater Rhea’s size is a major asset for its survival in the open grasslands and pampas of South America. As a flightless bird, their size is also crucial for defense. Their height allows them to spot predators like pumas and jaguars from a distance. And when they need to escape, their long, powerful legs allow them to run at speeds of up to 37 mph! Their size gives them the momentum and stride length to cover ground quickly.

Rheas are omnivores, eating a variety of plants, seeds, fruits, insects, and small animals. Their size allows them to have a larger digestive system, capable of processing a wide range of food items. They can also reach higher into vegetation to browse for food.    

Their large size is also crucial for thermoregulation. Living in environments with temperature extremes, their bulk helps them retain heat in cooler conditions, and their large surface area allows them to dissipate heat in warmer conditions.

hip displays, including wing flapping and running, and their larger size makes them more visually impressive. Once mating has occurred, the male rhea is the primary caregiver and his size can be intimidating to potential predators, offering some protection to his chicks.   

Essentially, the Greater Rhea’s size is a product of natural selection, favoring individuals that were better equipped to survive and reproduce in their specific environment. Their large size is a key factor in their ability to evade predators, find food, regulate their body temperature, and attract mates.

12. Marabou Stork

If we were listing the scariest bird, the Marabou Stork (Leptoptilos crumenifer) would probably win. Apart from their striking features, they are very large birds standing up to 5 feet tall with a wingspan that can reach a staggering 8.5 feet! They are one of the largest flying birds in the world.  

This African bird is mostly covered in dark grey or black feathers, with a white underside. They have a bare, pinkish head and neck, which often looks a bit sunburned. This lack of feathers is an adaptation for their scavenging lifestyle, keeping them cleaner when they feed on carcasses, just like vultures. A distinctive feature of the Marabou Stork is its large, inflatable throat pouch. This pouch hangs down from their neck and is particularly prominent during the breeding season. It’s used in courtship displays and also acts as a resonating chamber for their guttural calls.  

A truly bizarre fact about the Marabou Stork is that their legs are long and grey, but often appear to be white, which is actually their own droppings! They defecate on their legs as a form of thermoregulation, helping to keep them cool. 

Final Thoughts

So, the biggest bird in the world depends on whether you are looking at wingspan, weight, or height. All the birds I have listed have impressive statistics and often have more than one remarkable feature. Overall, you would have to conclude that the African Ostrich is the largest bird in the world, taking out the titles for heaviest and tallest.