Bird eggs are found in many sizes, shapes, colors, and textures depending upon which bird they come from. Bird eggs differ from other animal eggs in the fact that they have hard, chalky shells. Some eggs are very plain whereas others are brightly colored. They can even be spotted or speckled. However when it comes to the anatomy of a bird’s egg, they all have a seven things in common.
All bird eggs are encased by a hard shell. The shell itself is made of calcium. Not only does calcium make the shell hard, but it also helps develop the embryo’s bones. The hard shell also helps aid in protecting the vital parts inside the egg.
If you held a bird’s egg in your hand you may not be able to see the pores in the shell. However, if you put the egg in a glass of water you will notice tiny bubbles emerging from the shell and rising to the top of the water. The purpose of these tiny pores is to allow oxygen and water inside the egg while also allowing carbon dioxide to leave.
Just beneath the hard shell you will find the shell lining. This is like the womb of the bird. You may notice that many bird eggs are somewhat oval in shape. At the more rounded end of the egg there is a pocket of air between the shell lining and the shell. This allows the embryo to receive oxygen.
The egg white’s function is quite simple. It provides the embryo with water. The egg white also acts as a shock absorber helping to cushion the embryo. It’s like the embryo has its own water bed.
The eggs yolk has a simple yet very vital role in the development of an embryo. The yolk is where all the food for the embryo is stored.
If you have every cracked an egg into a frying pan, you may have noticed white strands close to the egg yolk flowing out into the egg white. These are the twisted strands. The purpose of these twisted strands is to keep the embryo upright when the egg is being turned. Many mother birds will turn their eggs frequently because this allows the egg to be warmed evenly.
The embryo is the developing bird. It is the reason for all of the parts of the egg to exist and function. To find the embryo inside the egg you will have to look at the yolk. The white spot in the yolk is a sign of a growing embryo.
To study the inside of an egg without having to crack the egg open, there is a simple method for this. Simply place an egg inside a clear jar of white vinegar. Over the course of a few days the hard outer shell will dissolve away, leaving the shell lining perfectly intact. As long as the lid of the jar is leak proof, you can turn the jar and watch the twisted strands to their job. This is a great experiment for children as well as adults.