Simple as it is, a bird’s egg is a very clever piece of engineering. It has to be strong and weak at the same time. It has to be tough enough to protect the young bird growing inside and weak enough to let the baby bird break out when it is ready to hatch. Nature’s answer to this is to make eggs curved.
Any pressure on the outside of the shell com presses it. This makes it stronger. And by being stronger it gives added protection to the young bird. Try breaking an egg by squeezing it in your hand and you will prove the point for yourself. (But have a bowl ready in case you squeeze too hard!)
A strong shell is ideal for a bird while it is growing, but when it is ready to hatch the shell must let it out. This is where the curved shape scores again. When the baby bird begins pecking and pushing from the inside, the shell is not com pressed and breaks easily.
Picture Credit : Google
