Scientists know why birds' eggs are different shapes. People once said male chicks came from rounder eggs, but that was wrong. Scientists say the shape makes birds fly better. A professor said birds have changed to lay eggs that have different shapes - from a round owl's egg to a pointy sandpiper egg.
The scientists looked at 50,000 eggs from 1,400 different bird species. They looked at the shape, length and height of the eggs. 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.