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Our science activities today are inspired by a lively guessing book, Whose Egg Is This? by Lisa J. Amstutz.

The premise of the book is to guess who laid the eggs in the large, colorful photograph on the left page by matching them with one of the four animals in photographs on the right page. Fortunately, each page comes with plenty of helpful hints, so even if the child doesn't recognize the egg, he or she will likely be able to figure it out. Answers are also provided in the back.

This is a great format for a children's book. It encourages children to observe closely and it engages their curiosity. It is fast-paced and fun. It is sure to inspire more activities and experiments like these:

Activity 1. Who is oviparous?

Oviparous means an animal that lays eggs. (Technically, lays eggs without further development of the embryo while it is in the mother.)

Brainstorm to create a list of different animal groups with egg-laying females.

Birds are probably the first to come to mind. They are the only animal group where all the members lay eggs.

What other vertebrates lay eggs?

What about

  • reptiles?
  • amphibians?
  • fish?

Can you find any exceptions, like snakes that give birth rather than lay eggs?

Turtles and tortoises lay eggs.

What about mammals? Mammals that lay eggs are in the group called monotremes, which include the platypus and echidnas.

Do any invertebrates lay eggs?

At least some species of

  • Insects
  • Spiders
  • Crustaceans, like lobsters
  • Some molluscs, like snails
  • Flatworms
  • Earthworms
  • etc.

Can you think of any others?

Activity 2. Compare and contrast the eggs of various animals.

Look at photographs of different types of eggs.

How are eggs that are laid in the water different from those laid on land?

Are all eggs covered with a hard, rigid shell?

Are they all the same size?

What about color?

Do you know whose eggs were in the photographs? (Answers at bottom of post).

3. Investigate egg anatomy

Surprisingly, an egg can be quite complex inside. There are multiple layers and structures.

(Illustration by Horst Frank at Wikimedia)

Schematic of a chicken egg:
1.    Eggshell
2.    Outer membrane
3.    Inner membrane
4.    Chalaza
5.    Exterior albumen (outer thin albumen)
6.    Middle albumen (inner thick albumen)
7.    Vitelline membrane
8.    Nucleus of pander
9.    Germinal disk (blastoderm)
10.    Yellow yolk
11.    White yolk
12.    Internal albumen
13.    Chalaza
14.    Air cell
15.    Cuticula

The Exploratorium has a series of egg-vestigations for looking inside an egg, including

4. The Color of Bird Eggs - In the News

Birds eggs come is an astonishing array of colors.

Poster of bird eggs - (Note:  This poster does have stylistic diagram of a bird's internal reproductive organs, in case you aren't ready to go there )

Scientists have begun to realize that the color of bird eggs may be about more than just camouflage and there has been a recent burst of studies examining various aspects of color and speckling patterns.

For example, speckling may add structural support to the shell and as well as protection from direct exposure to the sun. The speckles may protect against ultraviolet rays while allowing enough light it so the chick inside can adjust its internal clock. Or the speckles may absorb heat and help maintain temperatures when the incubating parents are away from the nest.

Ornithologists (scientists that study birds) have found that species that are the target of nest parasites, like cowbirds, are sometimes better able to recognize the color patterns of their own eggs than species that aren't as susceptible.

It seems likely that how egg color works will differ between different species of birds and may serve more than one purpose. Sounds like some great potential for science fair projects.

To study bird egg speckles with youngsters, try this craft to make artificial speckled eggs. See if eggs with speckles or without are easier to find when hidden in the grass.

If you are interested in participating in a citizen science project, Caren Cooper put out a call for photographs of the eggs in house sparrow nests last year. The speckling of house sparrow eggs varies quite a bit. The instructions ask that you include  a white piece of paper and a penny in the photograph for scale.


Wired magazine has a popular science article "Debate Over Purpose of Bird-Egg Coloration Continues"

For a scientific review, see CHERRY, M. I. and GOSLER, A. G. (2010), Avian eggshell coloration: new perspectives on adaptive explanations. Biological Journal of the Linnean Society, 100: 753–762. available online

If you have early elementary-aged children, be sure to take a look at Whose Egg Is This? by Lisa J. Amstutz.

Paperback: 32 pages
Publisher: Capstone Press (January 1, 2012)
ISBN-10: 1429678542
ISBN-13: 978-1429678544

This book was provided by the publisher for review purposes.

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(The eggs in photographs are frog eggs and snail eggs.)


Today we were inspired two bright and colorful books for first graders, Macaws by Cecilia Pinto McCarthy and Rain Forest Life by Janine Scott. These two books would be perfect to accompany a trip to the zoo or a unit on rain forests for the youngest set.

Macaws are from Mexico, Central and South America. Their bright colors and inquisitive natures make them popular with humans.

Facts about Macaws:

  • have colorful feathers
  • can live 50 years or more
  • have strong beaks for eating fruit and seeds
  • males and females pair for life
  • nest in tree cavities
  • travel in flocks

Most macaws live in rain forests. A rain forest is a place with trees that gets a lot of rain. How much rain? Some rain forests get up to an inch of rain per day, or 365 inches per year! Rain forests are often found in warm, tropical regions, but there are also cooler rain forests. An example of a cooler climate rain forest occurs in the west coast of the state of Washington.

Tropical rain forests are home to an abundance of interesting, colorful, and unique birds, in addition to macaws:


1. Bird Beaks

Birds use their beaks for many of the same purposes that we humans use our hands. Birds eat with their beaks, build nests with them, and even groom themselves with them. Birds do not have teeth, but they do have tongues.

One of the first things you might notice about the macaws, toucans, hornbills and hummingbirds is how different their beaks are.

(Photograph of hyacinth macaw by Malcolm at Wikimedia)

The macaw's beak is long and curved on top, coming to a hook at the end. The lower beak is short and stubby in comparison. It looks rather like a can opener.

Check out how these wild macaws use the pointed tip of their beak and their tongue to remove nut meats from nuts. Note: This video has numerous pop-up ads.

The toucan's beak is so large that you might wonder how it flies. It turns out that the beak is very light. Toucans eat mostly fruit, although they also eat insects.

The hornbill's beak is also very large. The structure on the top is called a "casque" and it is thought to be involved with calling (sound production). Larger hornbills have a diet similar that of the toucan. Smaller ones are omnivorous (they eat many things), or even carnivorous (eating only meat).

The hummingbird's beak is long and slender like a needle. Known for drinking nectar from flowers, hummingbirds also eat small flying insects.

Eating like a Bird

1. Food


  • various small fruits like blueberries, raisins, nuts, 0-shaped cereals, gummy worms, and small crackers (check about food allergies beforehand and avoid foods with those ingredients). If you don't want the children to snack on the food afterwards, choose inedible items like un-popped popcorn and packing peanuts.
  • plates or dishes to present the food on
  • variety of equipment to mimic bird beaks, such as tongs, toy pliers, toothpicks, chopsticks, tweezers or forceps, and straws
  • paper cups or similar containers to act as the bird's "crop" (where the food goes)
  • timer (optional)

Depending on the number of children and the amount of food and equipment you have, you might want to form small groups.  Explain that the children are going to "eat like a bird." Suggest that they try to put the different food items into their "crops" (cups) using the different tools, but not to use their fingers. Present each child/group with a plate holding an assortment of food items and allow them to freely explore the options. Do some tools work better than others? Brainstorm about what might be other challenging foods that birds might eat. How would you eat an oyster or a snail without hands? How would you eat a fish without dropping it? What other types of tools might be helpful?

Handling time:

Introduce the idea of "handling time," that is the amount of time it takes to pick up, process and eat a particular food item. Using a single tool and a timer, see how many pieces of a particular food they can get into their crops (cups) in a short period of time, such as a minute. Try other kinds of food for the same length of time. Weigh the amount of each type of food that was gathered to discover which type was most efficient, or resulted in the most food consumed per minute. Graph the results.

Another way to perform this test might be to time how long it takes to pick up a particular number of one type of food item with different tools. For example, how long does it take to pick up 30 raisins with tweezers versus toothpicks?


Have you ever watched a bird drink? Notice how these chickens scoop up water and then tilt their heads back to let the water flow down their throats.

Drinking is also a challenge with a beak. Often the tongue helps. Scientists have recently discovered that hummingbirds have a tongue like a mop that they use to slurp up nectar. If you've ever visited a lorikeet exhibit, you might have seen the brush-like tongues they use to lap nectar.


  • straws
  • spoons
  • new toothbrush
  • juice
  • shallow bowls

Pour the juice into shallow bowl. Compare how easy it is to drink with a straw or spoon versus try to drink by collecting fluid in the bristles of a toothbrush.

2. Bird Craft

One thing that catches your eye about these tropical birds is their colorful feathers. Make a brightly colored bird.


  • craft pom poms (2 sizes, body and head)
  • colorful feathers (available at craft stores)
  • matching color chenille pieces, cut into short lengths for beaks
  • sewing thread
  • white or craft glue
  • scissors

Chose 1 large pom pom for body and one smaller pom pom for the head for each bird. Take a few minutes to study the structure of the feathers. Find two similar feathers for wings and one for a tail. If the feathers are widely different sizes you can trim them with scissors. Choose a section of chenille to serve as a beak. Bend the chenille into a v-shape, if desired, or leave it long to serve as a hummingbird beak.

Glue the head and body together. Set aside to let dry or the head may slip when adding other elements. If you are doing a flock of birds, you can glue some while others are drying. Put a bit of glue on the hard tip of each feather (where it attached to the bird in real life) and insert it into the body on either side to form wings. Add glue to the hard tip of the tail feather and insert it on the opposite side from the head. Finally add some glue to the tip of the chenille and add to front of head, taking care not to move the wings and tail. Allow to dry.

Once dry, tie a length of thread around the body and hang up. You can create mobiles or flocks of birds or use them as puppets.

3. Bird homes and rainforest layers

The rainforest is divided into layers.

The emergent layer consists of the very tallest trees that push up through the canopy.

The canopy is the dense layer of treetops.

Under the canopy there may be little light. Wherever light passes through the canopy, young trees, shrubs and vines can grow. The forest floor is also teeming with life.

Birds like the hoatzin use the trees of the rainforest for homes and food.

Many birds live in the canopy layer of the rainforest, although some nest in the shrubs and vines of the understory. Ant birds follow army ant swarms running over the forest floor, catching insects and other arthropods chased up by the approaching ants.

Project:  Chose a rainforest bird that interests you and find out where it lives in the rainforest. Does it nest in trees in the canopy or shrubs in the understory? Where does it find food?

Prepare a short report and share what you have found out with others.

Macaws by Cecilia Pinto McCarthy

Reading level: Ages 4 and up
Library Binding: 24 pages
Publisher: Capstone Press (August 1, 2011)
Language: English
ISBN-10: 142966049X
ISBN-13: 978-1429660495

Rain Forest Life by Janine Scott

Reading level: Ages 4 and up
Paperback: 24 pages
Publisher: Capstone Press (August 1, 2011)
Language: English
ISBN-10: 1429671521
ISBN-13: 978-1429671521

Books were provided by publisher for review purposes.

See our growing list of children's books about birds at Science Books for Kids.


Quick, what are the states of matter?

If you said solid, liquid and gas you are almost right. Almost? It turns out that many scientists now agree there is a fourth state of matter called plasma, and very possibly others. It is distinct from the other states of matter in its properties and it is extremely common. In fact it is the most abundant state of matter in the universe by far.

If it is so common, then why hasn’t everyone heard of it? Or if you have heard of it, why aren’t you really clear what it is?

One problem may be the term plasma. Plasma is a word also used for the fluid in blood that carries the cells and other materials from place to place. Same word, two very different meanings, but that happens all the time in the English language.

The state of matter plasma is a gas that has been energized so much some of its electrons have come flying off. It can also be called ionized gas, but that is confusing because it sounds like it is just a special kind of gas. Scientists have realized that plasma behaves differently from gas, and is a separate state.

To help you develop a better understanding, let’s look at some examples of plasma.

A flame is a simple form of plasma, where only a few of the gas molecules have lost their electrons and become ionized. Lightning is a much more intense form of plasma. The sun and stars are plasma.

You can even have plasma in your home, if you have any neon signs or lamps. You can also buy plasma balls. Inside the glass ball, electric fields pass through a gas that has been charged to make it plasma. Here is a YouTube video that shows one.

If your children are not very familiar with the concept of an atom, it might be a great time to review. One of my favorite demonstrations of atoms uses a pile of oranges and some tennis balls. The oranges are the protons and neutrons and they sit in the center of the atom. You can put a P or N on the oranges, too. The tennis balls are rather wacky and can bounce around all over the place. They are the electrons. If you have gone over the periodic chart, then find some actual elements to create using the atomic mass and atomic number. Choose a simple gas like helium, which has 2 protons, 2 electrons and 2 neutrons. Relate your atom to the gas found in balloons that makes them float.

Once you have created a few atoms, now you can strip away the tennis balls, leaving the oranges. Now you have created plasma, a gas that has lost some of its electrons and has become charged or ionized. Note: not all the electrons need to be lost, and not all the atoms have to lose electrons. Only a few lost will be enough.

The Coalition for Plasma Science has educational materials and links to other websites.

I also found a fun game to help understand plasma by sorting items into the different states of matter at the Space Weather Center.

Here are a few plasma balls you can buy for your own experimentation in various sizes and prices. Just remember they are made of glass, and be careful with plasma balls around young children.

Plasma Ball 3.5 Inch USB or Battery Operated

Plasma Globe

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