The kori bustard (Ardeotis kori) is the heaviest flying bird in the world, with males weighing between 11 to 19 kg and having a wingspan of 2.75 meters.
According to the Guinness World Records, the largest specimen of the kori bustard weighed 18.14 kg. This bird was shot in South Africa and recorded in 1936. The Smithsonian National Zoo notes that females are about half the size of males.
Kori bustard flying in the air. (Photo: Pixel).
This species inhabits two separate areas in Southern and Eastern Africa, spending most of its time foraging on the ground. Their diet is quite diverse, including insects, reptiles, and small rodents, as well as seeds, berries, and roots. The International Union for Conservation of Nature (IUCN) classifies the kori bustard as near threatened and describes them as a sedentary species, moving only locally within their range.
The second heaviest flying bird in the world also belongs to the bustard family. It is the great bustard (Otis tarda). They are slightly lighter than the kori bustard, with a maximum weight of around 6 to 18 kg. Unlike the kori bustard, which does not migrate and rarely flies far, the great bustard has a migratory route of over 4,000 km between its breeding grounds in Mongolia and its wintering grounds in China. The great bustard also exhibits sexual dimorphism and can have the largest size difference between males and females in the bird world, with males weighing four times more than females.
In contrast, the heaviest flightless bird in the world is the South African subspecies of the ostrich. The South African ostrich (Struthio camelus australis) can weigh up to 156 kg. The heaviest flying mammal is the flying fox, which weighs between 0.5 to 1 kg, depending on the specific species.
