The question of which bird is the “biggest” does not have a single answer, as “biggest” can refer to various measurements. Different birds hold records depending on whether size is defined by height, weight, or wingspan.
The Heaviest and Tallest
The Ostrich (Struthio camelus) is the world’s largest living bird in terms of both height and weight. Adult males can reach an impressive height of up to 2.75 meters (about 9 feet), with nearly half of this height attributed to their long necks. These birds can weigh over 150 kilograms (330 pounds), making them the heaviest avian species on Earth.
Ostriches are flightless birds, lacking the keeled breastbone needed for flight muscle attachment. Their habitat spans dry grasslands, shrublands, and savannas across much of Africa. Powerful legs, uniquely equipped with only two toes, allow them to run at speeds up to 72.5 kilometers (45 miles) per hour, making them the fastest two-legged animals. Ostrich eggs are also the largest, averaging about 1.35 kilograms (3 pounds) and measuring around 150 millimeters (6 inches) in length.
Longest Wingspan
When considering wingspan, the Wandering Albatross (Diomedea exulans) has the largest span. Its wings can stretch nearly 3.5 meters (approximately 11 feet 6 inches) across. This wingspan is an adaptation for its life at sea, allowing it to glide for hours over the ocean with minimal energy expenditure.
Wandering Albatrosses spend most of their lives in flight over the southern oceans, landing primarily to breed and feed. Their long, narrow wings are designed for efficient dynamic soaring, utilizing wind currents and updrafts to travel vast distances, sometimes covering 6,000 kilometers in just twelve days. While the Wandering Albatross has the record, other birds like the Andean Condor have notable wingspans, reaching up to 3.3 meters (10 feet 10 inches).
Heaviest Flying Birds
Heaviest flying birds achieve flight despite their considerable mass, unlike the flightless Ostrich. The Kori Bustard (Ardeotis kori), found in eastern and southern Africa, is considered the heaviest flying bird. Male Kori Bustards can weigh up to 19 kilograms (42 pounds), although they prefer to walk and fly only when necessary due to their weight.
The Trumpeter Swan (Cygnus buccinator), particularly in North America, is another heaviest flying bird. Male Trumpeter Swans average over 12.7 kilograms (28 pounds) and reach lengths of up to 1.8 meters (6 feet). Getting airborne requires significant effort, often needing a long “runway” of open water for takeoff. These large waterfowl inhabit wetlands across parts of North America.