According to the International Birdlife Council (IOC), as of December 2021, there are about 11,198 species of birds that have been described and named, belonging to 231 families and 2,288 genera. These birds are distributed all over the world, and different regions and ecological environments have their own unique species.
It should be pointed out that there are still some birds that have not been discovered and described, and there are also some controversial bird classification issues, so the specific numbers may change. But in general, the world's bird species are quite rich, and people's understanding and knowledge of them are constantly deepening and expanding.
