What Is the World’s Biggest Bird, Past and Present?

Birds represent an astonishing array of life forms, with some species evolving into truly colossal creatures. Humanity has long been captivated by the extremes of the natural world, especially avian size. Exploring the largest living birds and the giant species that once roamed prehistoric landscapes reveals the remarkable scale birds can achieve.

The World’s Heaviest and Tallest Living Bird

The Common Ostrich (Struthio camelus) is the world’s heaviest and tallest living bird. Adult males reach heights of up to 9 feet (2.75 meters) and typically weigh between 200 and 300 pounds (90-136 kilograms), with some individuals exceeding 330 pounds (150 kilograms). The ostrich possesses a long neck, muscular legs, and two-toed feet, adapted for terrestrial life. Males have black plumage with white wing and tail feathers, while females are brownish-gray.

Common ostriches inhabit grasslands, savannas, shrublands, deserts, and open woodlands of southern and eastern Africa. Their omnivorous diet consists mainly of plants, but also includes insects, lizards, snakes, and rodents. These flightless birds, due to their immense size, are the fastest two-legged animals on Earth, running up to 43 miles per hour (69 kilometers per hour). Their powerful legs deliver kicks, and their large wings, though useless for flight, are used as rudders for steering at high speeds.

The World’s Largest Flying Birds

Defining the “largest flying bird” considers different metrics, primarily wingspan and weight. For sheer wingspan among living birds, the Wandering Albatross (Diomedea exulans) has the largest, reaching up to 11 feet (3.4 to 3.65 meters). These seabirds are adapted for oceanic flight, possessing long, narrow wings and a unique shoulder-lock mechanism. This allows them to glide for extended periods with minimal muscular effort. They spend most of their lives soaring over the Southern Ocean, utilizing wind currents for dynamic soaring and rarely flapping their wings.

For the heaviest birds capable of flight, the Great Bustard (Otis tarda) and the Kori Bustard (Ardeotis kori) are top contenders. Male Great Bustards, found across Europe and Asia, weigh between 22 and 35 pounds (10-16 kilograms), with some reaching 46 pounds (21 kilograms). They have a wingspan of 7 to 8 feet (2.1-2.4 meters). The Kori Bustard, native to Africa, has males weighing between 28 and 44 pounds (13-20 kilograms), some exceeding 44 pounds (20 kilograms), and a wingspan of up to 9 feet (2.75 meters). Both species are primarily ground-dwelling, preferring walking and taking to the air only when necessary due to their laborious takeoff.

Giants of the Avian Past

The fossil record reveals ancient birds that dwarfed even today’s largest species. Argentavis magnificens, an extinct bird from the Late Miocene of Argentina, was once considered the largest flying bird. While early estimates suggested wingspans of up to 28 feet (8.3 meters), recent analyses place its wingspan between 16 and 21 feet (5 to 6.4 meters), weighing around 150 to 160 pounds (70-72 kilograms). This bird was likely an expert glider, relying on thermals and air currents for flight, as it was too heavy for sustained flapping.

Pelagornis sandersi holds the record for the largest wingspan of any bird yet discovered, estimated between 19.9 and 24.2 feet (6.06 to 7.38 meters). This marine bird soared over North American oceans 25 to 28 million years ago, demonstrating efficient gliding flight. Among the heaviest birds to ever exist were the Elephant Birds of Madagascar, particularly Vorombe titan. These flightless giants stood up to 10 feet (3 meters) tall and weighed up to 1,900 pounds (860 kilograms), averaging around 1,400 pounds (650 kilograms). Their massive size allowed them to fill ecological niches similar to large mammals in their Madagascan habitat.