As the biggest ostrich, why can't it fly?

Now spring is blooming, and it's the season for migratory birds to fly back. We can see many geese flying back from the south to the north in droves. However, not all birds can fly. For example, as the largest ostrich, it just can't fly. So since it is a kind of bird, why can't it fly? Today we will discuss this problem.

First of all, I think it has something to do with its internal structure. We know that birds can fly. Their bones are tough, and the inside of the femoral head is hollow. They are thin and light, so to speak. The bones in their chests are connected together to form a curved arch, which greatly helps them reduce air resistance when flying in the air. However, the ostrich's body shape and bone structure up to 2.5 meters are also very strong and heavy, without the bones of birds, and it is very light. Besides, its sternum is not.

Secondly, birds' eyesight is very developed, which helps them to find the position of food accurately even when flying in the air, and sense the direction of flying in the sky for them. However, the ostrich's eyeball is the largest on land, and one eyeball can weigh 60 grams. Although he can see a distance of 3 to 4 kilometers, how can he fly with such a heavy eyeball? This feature is conducive to his survival in the desert and is not suitable for flying in the sky.

Then I think the important thing is its feathers. We know that the feathers of birds are streamlined, and the feathers on the surface are not so soft to the touch. Sometimes they feel like plastic. In the picture, we can see that the ostrich feathers are streamlined, but the feathers are unevenly distributed and drooping, so it is difficult for ostriches to fly for various reasons.