Loons, gulls, puffins and petrels are some of the 100 species of birds that can both fly and swim. These diving birds can plunge into water to swim after prey, and leap back into the air to fly away.Loons, gulls, puffins and petrels are some of the 100 species of birds that can both fly and swim. These diving birds can plunge into water to swim after prey, and leap back into the air to fly away.[#item_full_content]