Birds’ eggs have different shapes, such as round, oval and pointy. The scientists observed 50,000 eggs from 1,400 different bird species. They looked at the shape, length and height of the eggs. Scientists know why birds’ eggs are different shapes. People once said male birds came from rounder eggs. But that was wrong. Scientists say the shape makes birds fly better. Birds with the most-oval-shaped eggs were the best fliers. Hummingbirds have the most-oval-shaped eggs. Owls have the roundest eggs. And sea birds have the pointiest eggs.