Birds exhibit an astonishing array of sizes and forms, from tiny hummingbirds to towering flightless giants. The “biggest” bird can vary significantly depending on the criteria used. Size may be determined by mass, height, or wingspan, with each metric revealing a different avian record holder.
The Heaviest and Tallest
The common ostrich (Struthio camelus) is both the heaviest and tallest living bird. Male ostriches can stand up to 2.8 meters (9 feet) tall and weigh over 150 kilograms (330 pounds), with some individuals reaching 156.8 kg (346 lb). Their long, unfeathered legs with two toes support remarkable speed. Ostriches can run at speeds of up to 72 kilometers per hour (45 mph), capable of sustaining 50 km/h (31 mph) for up to 30 minutes.
These flightless birds inhabit the open country and savannas of Africa, using their height to survey vast distances for predators. Ostrich eggs are the largest of any living bird, averaging 1.4 kg (3.1 pounds) and measuring about 15 cm (6 inches) long. Females lay their large, glossy cream-colored eggs in a communal nest, with males often taking on incubation duties at night.
The Largest Flying Birds
While the ostrich dominates in height and weight, the largest birds capable of flight face challenges due to aviation physics. Among the heaviest flying birds are the Kori Bustard and the Great Bustard. The Kori Bustard (Ardeotis kori) from Africa is widely recognized as the heaviest by average weight, with males typically weighing between 11 and 19 kilograms (24-42 pounds). Some exceptional males can reach up to 20 kg (44 lb).
The Great Bustard (Otis tarda) of Europe and Asia is also considered one of the heaviest flying birds, with males often weighing 10 to 16 kg (22-35 pounds) and verified specimens reaching 21 kg (46 pounds). These large, ground-dwelling birds are strong fliers. The Andean Condor (Vultur gryphus), a New World vulture, also has a maximum weight of 15 kg (33 pounds) and an impressive wingspan. This scavenger relies on thermal updrafts to soar with minimal effort over the Andes mountains.
Birds with the Longest Wingspan
The Wandering Albatross (Diomedea exulans) has the largest wingspan of any living species. This seabird, found in the Sub-Antarctic oceans, boasts an average wingspan of 2.5 to 3.5 meters (8.2 to 11.5 feet), with the largest recorded individual reaching 3.65 meters (12.0 feet). This immense wingspan is an adaptation for its pelagic lifestyle, allowing it to glide effortlessly over vast ocean distances.
The Wandering Albatross can travel thousands of kilometers without flapping its wings, utilizing dynamic and slope soaring techniques to conserve energy. Its wings feature a shoulder-lock mechanism, keeping them extended with minimal muscular effort. This efficient flight enables the albatross to spend most of its life at sea, only returning to land for breeding.