Easter Week: Science: Eggs, Eggs, Everywhere, Part Seven: Hard Shells vs. Soft Shells and Egg Shapes

We are finding so many ways to sort and graph our eggs. This time we looked at which one have soft shells and which have hard shells. We were able to make the generalizations that bird and insect eggs tend to have hard shells while reptile and amphibian eggs have soft shells. Amphibians tend to have a jelly-like substance surrround the eggs.

We also talked about the different shapes of the eggs. The elongated shape of the eggs help the parent to turn the eggs while incubating them to keep them warm. The pear-shaped eggs laid by birds like the murre, pivot in a circle so that it is less apt to roll. The eggs that are not turned during incubation tend to be more rounded.

We talked about how shape can affect how an object moves. We set up a ramp and rolled a round ball down it and saw that it rolled fairly straight, perhaps curving slightly toward the end of its roll, but generally straight.

Then we rolled the plastic eggs down the ramp and could see that it distinctly curved in its path.

We then talked about how birds turn their eggs a dozen times an hour and that the oval shape makes it easier for them to turn the eggs. If the egg does roll, it rolls in a circular pattern, just like the plastic egg did on their ramp, making it head back to its starting point.

I then asked them which way it curved and they rolled more eggs and concluded that it rolled toward it's more pointed end. We talked about how the Murre uses no nest materals by lays its one egg on the ledge of a cliff near the ocean. The eggs has an even more elongaged oval with a thinner pointed end than the chicken egg we are used to seeing. Because it is so thin on its end, it rolls in a sharper circle and this keeps it from rolling off the cliff. Murre Eggs are interesting in another way as well. They come in many colors and patterns so that the parent bird can recognize their own egg among all the eggs on the cliff that don't have nests to keep them seperate.



Eggs, Eggs Everywhere, Part Six: What Happens Inside An Egg?

This week we looked at what is inside a chicken egg.

Quentin cracked an egg inside a bowl and the boys looked at the different parts, and touched them, feeling the different textures. They are quite familiar with eggs because of helping me out in the kitchen so much, but they had never really looked closely at one. (Sorry I didn't get a shot until after they were done with it and by that time the yolk had broken and spread.)

We washed our hands after to protect ourselves from possible salmonella germs.

I found this worksheet that shows the parts of the egg and I thought it would be a nice idea to make a flat, layered model of it. So, I got out craft foam, paper and yarn, and we cut and glued and learned new names for the parts.

I continue to be surprised at how much individuality the boys can bring to their projects. Quentin opted for orange construction paper rather than the yellow craft foam I had imagined them using. He also decided to draw his chalazae, the string-like fibers that hold the yolk in the middle of the egg, rather than use yarn.

James decided to use this whispy yarn we had.

Alex used some yellow yarn and seperated the fibers a little.
They all used cut-outs of the terms to label their eggs.

Alex's

James'

Quentin's

We also looked at egg development. When Katie was in first grade we did a duck hatching project, but the project is quite a commitment and I didn't have that time this spring. I would like to so it again in the future, but for now, to help them understand what was going on inside the egg, I found this page  that shows the stages of development of the chicken (last page).

It is supposed to be made into a wheel with paper plates,

but we are going to make booklets instead,

but then again they may each decide to do it slightly differently.

Eggs, Eggs Everywhere, Part Five: Colors and Sizes

I had some coloring pages that had a variety of eggs on them for them to compare and contrast. We talked about camouflage and how some eggs were colored to take advantage of this but that others did not need camouflage. We then painted the egg pictures as accurately as possible.

The Ostrich egg is 8 1/2 inches long and 6 1/2 inches wide.

We also discussed the variety in the sizes of the eggs, and how, for the most part, that size of the egg depended on the size of the adult, the larger adults having the larger eggs, for example. We also talked about the difference between precocial birds, or birds that can run and feed themselves shortly after hatching and altricial birds or birds that are helpless, blind and usually naked after hatching. The precocial birds tend to lay larger eggs because they develop more in the egg.

The salmon egg is 1/4 inch round; the parakeet measures about 3/4 inch long and a little less than 1/2 inch wide at it's widest point; the quail is 1 1/2 inches long and 1 inch wide; the turkey is 3 1/4 inches long and 2 inches wide; the emu egg is 5 1/ inches long and 4 inches wide. All width measurements are at its widest point.

Once they painted them, we used them to play a few games. One was cut out and the names of them were put on the back and they could be used like flashcards. The other game was a matching game, matching cut-out ones to one on the page. This was to help them learn to pay attention to details more than it was important for them to know what any kind of egg looked like.

Eggs, Eggs, Everywhere, part four: Where Are Eggs Laid?

We drew a nice scene with a tree and a pond, a little field and a small cliff on our white board. Lots of places to find eggs. We looked at the animals we had put on our chart in terms of where they lay their eggs.

Then we put our egg-layers in our little scene. We had to think about the eggs and why different places would suit different animals and different eggs in order to figure out where they went. We noticed that the different classes tended to lay their eggs together, but not always.
Some eggs went underground, some in trees,  others on cliffs, some in water and others beside the water. Some animals, we discovered, can go in more than one place.

The boys added more details to the scene as we went along.
We also talked about camouflage and how the eggs could be hidden from predators.

Eggs, Eggs Everywhere, Part Three: Cultural Connections to Eggs

This week we looked at cultural connections to eggs. The ancient Persians were the first people known to exchange eggs dyed in festive colors, but Macedonia was the first country to merge the egg-decorating tradition with the celebration of Easter. In France and China there is a tradition of giving red dyed eggs for good fortune. In Mexico there is a tradition of cracking confetti-filled eggs called "cascaas" (egg shells) on people's heads. Ukrainians developed the wax-resist method of decorating eggs known as Pysanky, which means "to write" in Ukrainian.

I really wanted to do Pysanky eggs this year, but I just didn't get the materials in time.
Here is a step-by-step post at That Artist Woman on making Pysanky eggs, if you would like to try.
Instead we used the idea at Gingerbread Snowflakes and made ours with Sharpie markers.

Lots of information on Pysanky eggs at Learn Pysanky.

Or, you could do a Pysanky Egg with wax resist on paper. Idea from Alpha Mom.

Eggs, Eggs Everywhere, Part Two: How Many?

Continuing from last week's lesson, I had some coloring pages for them of different egg-laying animals.

As they colored them, we talked about how many eggs the different animals lay, and that the number of eggs an animal lays usually depends on the animal's chance of survival.

I asked them which of these animals had the least protection by the parents and face the most hazards and which had the most protection. We then made a parallel between the most protected animals had the least amount of eggs and the least protected had the most amount of eggs and that this insured enough but not too many offspring.

We looked at the animal classification chart in terms of this and could see some generalities.

One one end of the spectrum, (egg-laying) mammals take care of their helpless young and have few eggs and on the other end, insects emerge from their eggs as miniature adults and have many predators and therefore have many eggs.

Eggs, Eggs Everywhere, Part One: A Variety of Eggs and Animals

With plastic eggs so easy to find this time of year, I thought that I could find something educational to do with them. My boys are always up for an egg hunt, even if there isn't candy and such involved, so that was an easy starting point. I wanted to fill the eggs with small toy plastic animals that hatch from eggs -turtle, lizard, snake, bird, fish and the like, but I didn't have the time for a small toy search and ended up putting in pictures of the animals.

Once the egg hunt was over, and interest peaked, we talked about the different kind of eggs that animals lay. I read to them Ruth Heller's Chickens Aren't the Only Ones. If you have not read this book before, it is a must for the pre-K to 2nd grade crowd, although even my older kids like it because of its vividly colored and beautiful drawings.

We then went over classification and talked about the characteristics of each class. We then divided the animals according to their characteristics. We talked about the exceptions to the descriptions of the classes such as the egg-laying mammals. They were a little surprised to find out that there were egg-layers in each of the classes.