Bird Science Projects

The Case of the Disappearing Eggshell

An egg is covered by a hard shell to help protect the chick growing inside. When the chick is ready to hatch, it breaks the shell open. Try this experiment to find out what a shell is made of:

What You Will Need:

• An egg from the grocery store
• A drinking glass
• White vinegar

What To Do:

1. Set a raw egg in a glass of white vinegar so that it's completely covered in the liquid. Bubbles should start to form on the surface of the egg.
2. Let the egg sit in the vinegar for about 3 days and then take it out and rinse it in water, being careful not to pop it. Does it feel different from when you put it in the vinegar? Does it still have a white shell?

What's Happening?

The eggshell disappeared! But there might be some chalky white stuff left on the egg. This is because vinegar is a type of acid that "ate" away and dissolved the calcium carbonate that the shell is made out of. (Chalk is also made out of calcium carbonate!) When something dissolves, it breaks into very tiny pieces and mixes with a liquid. You can see it happening if you put a sugar cube into a cup of hot water and stir. The sugar cube disappears as the sugar dissolves into the water.

You might be wondering why the egg white and yolk inside the shell stayed in the shape of an egg even though the shell is gone. This is because the egg has another covering underneath the shell; called a membrane. It is very thin and you can see the yellow yolk through it. The vinegar can't dissolve the egg membrane, but some of it was able to get through the membrane, making the egg swell up.

The Shrinking Egg

In the last project, the egg membrane let liquid in, making the egg swell a little bit. Do this project to see if you can get the egg to shrink!

What You Will Need:

• The egg without its shell from the previous project
• A drinking glass
• Corn syrup

1. Carefully place the egg in a glass of corn syrup, so the egg is covered.
2. Let the egg sit in the corn syrup for about 3 days. Then take it out and see what happened!

What's Happening?

The egg shrank! This is because the egg membrane let a bunch of water pass out of the egg to try to balance how much water was inside the egg and how much water was outside it in the glass. The very tiny parts that make up corn syrup (called molecules) were still too big to pass through the membrane, so none of the corn syrup got inside the egg. The egg lost a lot of water, but didn't get anything to take the water's place, so it looks a little funny! Do you think it would fill up again if you put it in a glass of water? Try it out!

The fact that the egg membrane can let some things through is very important for a baby chick. Air passes through the membrane, just like water did in this experiment, and that allows the baby chick to breathe while it's inside the egg.

All About Feathers

When baby chicks hatch, they are covered with tiny, soft, fluffy feathers called down. Down helps keep them warm. (It can keep us warm too, which is why quilts and coats are often stuffed with down!) As they grow older, chicks grow bigger feathers called contour feathers. These are colored on the tips and downy at the base (the part closest to the body) to help keep them warm. They also grow long, strong flight feathers on their wings and tail. Look at a feather up close to learn more about it:

What You Will Need:

• A large feather (you can try to find one outside, or buy one from a craft store. Feathers you find outside can be very dirty, so make sure you wash your hands when you're done with this project!)
• Magnifying glass
• Velcro
• Water

What To Do:

1. Feathers help protect birds from getting drenched in the rain. Instead of soaking through them, water just slides right off! Turn on the water faucet so it is just a tiny trickle. Hold a paper towel underneath the faucet and watch how the water soaks right through. Next, put the feather under the trickle. What happens? The water should just roll off, leaving the feather dry. (If it doesn't, try turning the feather over.) Birds keep their feathers waterproof by putting a layer of oil on them. They get the oil from a place near their tail called a preen gland.
2. Look at a piece of velcro. Do you see how one side has tiny hooks that catch on to the other side? Bird feathers work a little bit like this. Take your feather between two fingers and rub your fingers down from the tip. The long, thin "branches" of the feather (called barbs) will separate into sections. Use a magnifying glass to look at the barbs: they are covered with tiny little hairs called barbules. Now take your fingers and smooth the barbs back together. The barbules catch each other and stick, like velcro. Sometimes you will see a bird rubbing its feathers with its beak. This is called preening and the bird does it to smooth the barbs back together.
3. What's that running down the middle of your feather? That's the rachis (say RAY-kuhs), and it makes the feather strong. Look at the very end, which is called the quill - does it look a little bit like a drinking straw? That's because it's hollow, to keep the feather from getting too heavy. People used to dip the quill in ink to use as a pen!

Website artwork, text and images Copyright © 2009 Home Training Tools, Ltd. All rights reserved.