How many species of modern birds is known to science?

There are various classifications of animals. About 10,000 bird species are known to modern science. But this number may differ from the real number. All due to the fact that the extinction of species is constantly occurring. 3 species disappear every hour. Also, not all species have been studied and discovered. Although the ground-air environment is fairly well studied, there remain places where researchers are discovering new species that were believed to be extinct or were not known until the moment of discovery. Therefore, this amount is constantly changing.