Ostriches are the largest and heaviest birds. Males can reach over two metres (6.6 feet) tall and weigh more than 150 kilograms (330lbs). It’s not too surprising then that they are capable of producing loud calls that can sometimes be confused with a lion’s roar.
Ostriches use a variety of whistles, snorts, bill-snapping and guttural noises to communicate with each other. They tend to roar during courtship displays, or when predators are close by.