The largest bird on Earth is the African ostrich, a flightless bird and the only species in the family Stolonidae in biological classification. African ostriches are approximately 183-300 cm long, 240-280 cm tall, and weigh 130-150 kg, with females being slightly smaller. A small head is supported by a slender, snake-like neck, topped with a short, flat, triangular beak composed of several horny sheaths.
The main characteristics of the African ostrich are its underdeveloped keel, which prevents it from flying. It is also the only two-toed bird in the world, with a dangerous nail about 7 centimeters long on each of its big toes. Its hind limbs are strong and powerful, adapted for running.
African ostriches live in the desert grasslands and savanna areas of Africa. Because their feathers, skin and meat have high economic value, and they have advantages such as fast growth, strong reproductive capacity, easy breeding and strong disease resistance, they are widely domesticated in many countries.
The African ostrich is the only species in the order Stoloniformes and a representative of the walking birds. The ostrich's ancestor was also a flying bird, and how it evolved into its present form is closely related to its living environment.
The ostrich is a primitive, surviving bird species, representing an evolutionary trend in open grasslands and deserts where animals gradually developed towards greater height and running ability. Simultaneously, its ability to fly gradually diminished until it was lost. The African ostrich's running ability is truly astonishing. Its toes have been reduced to suit running, making it the only bird in the world with only two toes, with the outer toe being smaller and the inner toe particularly well-developed. It can leap up to 2.5 meters and sprint at speeds exceeding 70 kilometers per hour. Furthermore, its powerful legs are the ostrich's primary defensive weapon, capable of killing even lions and leopards.
