What is the biggest bird in the world? How old is he?

An ostrich is a very big, flightless and fast-running bird. It is also the largest bird in the world, reaching 25 meters, with black and white feathers, a hairless neck, short wings and long legs. Generally, it reaches 80kmh, which is 90kmh faster.

In fact, the ancestors of ostriches were birds, so how did they become like this? This is closely related to the living environment. Ostrich is the original remnant bird, which means that the evolution direction of animals in the expanding grassland and desert natural environment is high, big and charitable. At the same time, the navigation ability gradually weakened until it was lost. The flying ability of African ostriches is very shocking. Because of jogging, its toes are lower. It is the only bird with only two toes in the world. The outer toes are very small, especially the inner toes are very developed. Bounce 2.5m, step more than 8 m, and the final sprint speed is more than 70km per hour. At the same time, big thick legs are also the key defensive weapons and equipment of African ostriches, and leopards can die.

In addition, some flightless birds are often classified as birds. In every island or unique area, they make up for the lack of breastfeeding. Well-known examples include Australian phobia, Australian birds and elephant birds in Papua New Guinea. Sadly, they were destroyed after human beings appeared. However, African ostrich, Australian wormwood, such as African ostrich, Australian grace, hare, Australian kiwi and African region.

The biggest feature of this bird is that the scapula is flat and there is no main keel bulge, but in the whole evolution process of the decline of navigation ability, there is no need for obvious muscles and attachment parts for navigation. However, whether this bird is closely related or not must have sufficient direct evidence of animal fossils. Interestingly, the dodo is also a kind of terrestrial bird that is difficult to fly, but it is not a blood relative of the bird, but a member of the young pigeon, so it does not have the characteristics of running like a bird.

According to the characteristics of birds all over the country, ornithologists have found that the world can be divided into six natural geographical regions, each region has unique birds, and the birds in the same region have extensive similarities, which is the result of evolution and adaptation to the new environment, among which ostriches are distributed in Isopia and Africa.

Ostriches are widely distributed in arid and rainless areas of Africa. In the tertiary period of Cenozoic era, ostriches were widely distributed in the subcontinent. In Zhoukoudian, the birthplace of China's famous Shanghainese dialect, not only ostrich eggs but also foot bones were found. Today, ostriches are found all over Africa, Yemen and Arabia. Now, the ostriches in Yemen and Arabian Peninsula have already disappeared all over the country, from the Andes to the south, and Australia introduced them from 1862 to 1869, creating new habitats in the southeast.

The head is small, wide and flat, and the neck is long and soft. The exposed head, neck and feet are generally pale pink, with a straight and short beak, a flat and round top, big eyes, inherited the characteristics of birds, and thick and black eyelashes. The hind legs are very thick, with only two toes (toes iii and iiv), which is different from ordinary birds. People with at least toes in birds have big inner toes (toe 13) and hard toes (claws), but no outer toes. The hind legs are strong. In addition to sprinting, they can also kick forward and attack.

The wings are big, but they can't fly because the scapula is flat, there is no keel B, the neck B drops, the feathers are evenly distributed, there are no feather areas and bare areas, and the feathers are fluffy and underdeveloped, and there is no bifurcation. The male bird with perfect feathers 1.75~2.75 meters high, so it is not heavy.

Male adult birds are mostly gray-black, and the wing feathers and tail feathers are milky white. Beautiful white wavy feathers and tail feathers set off Kuroha. Male birds are particularly eye-catching in broad daylight, and their wings and feathers are the key to finding the other half. The back hair of female insects is similar to that of male birds, but the dark brown and dark gray hair is not as gorgeous as that of male birds. Chicken feathers are brown-gray, with many shades, and they can't grow feathers until they are two years old. This kind of back hair is mainly for better and more convenient hiding. The two chicks look alike, even the ostrich chicks are not far apart. So far, it is impossible to distinguish women from men in appearance, only in reproductive organs.

Perfect male ostriches with small reproductive organs have mating devices. In mating season, the perfect male testis is fist-sized, but it will shrink in non-breeding period and will not swell until the next breeding season. The ostrich's pelvis is closed, and the upper and lower phalanges (pubis). ) closed at the midline. In particular, ostrich's urination and defecation are separated, which is different from other birds. Raw eggs are big and color like goose eggs. They are 15~ 20cm long and weigh 1400g, which is the largest among raw eggs. The eggshell is a little hard and can bear a person's net weight.