The diversity is pretty fascinating. About half of the 10k are songbirds, the largest group by far even though they’re believed to be the most recent to diverge. Many groups have ~200-300 species each, like owls or woodpeckers or parrots. Some that you wouldn’t expect have a bunch of species (150 cuckoos?! 114 kingfishers!) and then others barely have any (6 flamingos; 2 ostriches - tho they’re both very old)
There's quite a few more birds than mammals, though mammals are not especially diverse, esp. with 60% of mammal diversity in bats and rodents. There's at least 50k identified mollusk species, 65k identified arachnids, and with insects things go nuts with ~900k. There's around 60k identified vertebrate species overall (fish, mammals, reptiles, birds, amphibians, etc), the invertebrates ~1.3 million.