- Hummingbirds and Swifts – The smallest category of birds, this group includes more than 400 different species.
- Ostriches – The ostrich, the most famous flightless bird, is also the only species in its genus. It also holds the distinction of being among the largest birds.
- Owls – Another important type of bird is the owl. There are more than 200 species of owls across the world.
- Parrots and Cockatoos – This colorful group, which includes macaws, cockatiels and budgerigars, consists of more than 350 species. They are popularly kept as pets.
- Penguins – There are roughly 20 species of this flightless bird in the world.
- Perching Birds – Also known as passerines, this group includes more than 5,000 species, making it the largest and most diverse. Common types of perching birds include crows, swallows, jays, finches, sparrows, wrens, starlings and larks.
- Pigeons and Doves – This group includes more than 300 bird species. Pigeons are famous for ferrying messages for humans, and have been used in such a way since Roman times. They were also used during World War I and II and the Korean War.
- Shorebirds – More than 350 species are found in this group, including sandpipers, terns, oystercatchers and gulls.
- Waterfowl – Ducks, geese, swans and many other birds belong to this group, which includes more than 150 species.
- Woodpeckers and Toucans – Known for their distinctive beaks, this group is made up of more than 400 species.
