Multiple choice Which of the following is the tallest bird? Peacock Penguin Ostrich Emu Reveal answer Fill a bubble to check yourself C Correct answer Explanation Ostriches are the tallest birds in the world, standing up to 2.8 meters (9 feet) tall. They're also the heaviest and fastest-running birds. Peacocks, penguins, and emus are all large birds, but none match the ostrich's height.