Designed with children in mind:

The Smithsonian National Zoo has “A Walk in the Forest” with six different animated walks. One allows you to take soil samples and measure soil pH. Another helps you learn how to identify trees using keys. Each is led by an animation of a real employee of the zoo. How cool is that!

University of Illinois Extension has a virtual walk in the woods and Secret life of trees. Both show photographs of actual forests. There’s a teacher’s guide with ideas, resources and many extras.

For children or adults:

Ever wanted to visit a redwood forest? Muir Woods has a virtual tour. There are 92 photographs, and you get to choose where you look next. The virtual tour always has good weather.

Florida Hikes has slide shows from various Florida parks.Check out the giant snails at Pine Land. Isn’t fun to see how different the landscape is at the different parks?

Finally, YouTube has a number of videos of walks. I like this one because the tour guide discusses, what else, science!

Hope you enjoy these virtual walks in the woods, and can talk your own walk soon.

Where’s your favorite place for a hike?

1. Tree Transpiration

Transpiration is a fancy word for the movement of water out of trees and other plants. Did you know that almost twice as much water enters the atmosphere through plants as through the surface of the oceans? (Another benefit of trees!)

Gather:

• a nearby tree (outside) with branches you can reach
• clear plastic baggy for each child
• chenille or twist tie to hold bag around branch (enough for each child)

You might want to gather enough of these materials to compare branches on different parts of the tree and/or branches on different types of trees. (You will see the best results on a hot, sunny day.)

Place the bag over the tip of a branch so that it contains at least one leaf. Use the chenille or twist tie to close the bag around the branch to hold it closed. Make a prediction about what will happen. Now wait for 15 or 20 minutes and check the bag. See anything? Try again after 1/2 hour.

The bag should fill with moisture and condensation. Each tree leaf has tiny holes called stomata. Moisture exits the holes not only to cool the tree (like our sweat does for us), but also to help plants move materials up from the roots.

Were there any differences between different parts of the tree or different kinds of trees? What do you think would happen if you did the same experiment at night?

You can also perform this experiment indoors if you place a cut tree branch in a water-filled vase. Be sure to place the tree branch in a sunny window or under a bright lamp to encourage water movement into the plastic bag.

Extension (for older students):

Make up and perform experiments to test the factors that influence transpiration:

• temperature
• sunlight intensity
• water supply
• tree growth rate

Where does the water come from?

Most plants and animals need a lot of water every day. Trees absorb the water they need through their roots and then move it up to the leaves through the xylem.

2. How far does the water have to travel from roots to top of the tree? Let’s learn how to measure the height of trees.

There are several different methods to measure the height of any tall object, including a tree.

Method 1 (requires math):

Gather:

• a stick
• a tree that is apart from other trees (so you can see its entire shadow at least one time of day)
• tape measure (longer the better)
• paper and pencil

For this activity, you will need a sunny day. Place the stick upright in the ground near the tree. Use the tape measure to measure the height of the stick from the ground, and the length of the resulting shadow from the base of stick. Also measure the longest length of the tree’s shadow from the base of the tree. Assuming the two ratios are the same, solve for the height of the tree by multiplying the length of the tree’s shadow x (the height of the stick/the length of the stick’s shadow). See the illustration:

I found this video that discusses two other methods. You will need a second person to help you and a measuring tape.

Now, how far does the water need to move? If you take into consideration that a tree’s root may be a large or larger than its crown, then a tree one hundred feet tall may have to move water two hundred feet or more. That one big straw!

Let me know if you have any questions or other methods for measuring trees.

I. What is a tree?

Most of us recognize a big tree when we see one, but sometimes it may be hard to tell whether a plant is a large shrub or a small tree. What do you think? Brainstorm and write down all the words you use to describe a tree.

One definition might be “a tree is a perennial, woody plant that grows to at least 20 feet tall and has an erect (straight up) main stem.” Talk about what that means and if all the trees you know will fit this definition. Can you think of something more? Let us know what you decide.

II. Why study trees?

Trees are so important. Can you think of a list of benefits of trees? Here’s just a few we thought of:

• shade (really important in Arizona!)
• food and shelter for wildlife
• rubber
• paper and paper products
• source of wood products such as furniture, houses, pencils, musical instruments
• food for us
• fuel for heating
• medicines such as aspirin and quinine
• produce oxygen
• conserve water
• reduce pollution

Can you add to this list? Do some research to find more benefits of trees.

III. External parts of a Tree

Vocabulary:

• bark
• trunk
• crown
• leaf/needle
• branches
• roots
• twigs
• nuts
• fruit
• flowers
• buds

Make index cards with each of these names (make sure you have at least one card for each child participating.) Punch holes in the cards with a hole punch.  Cut pieces of yarn of various lengths. Find a tree outside and have the children attach the cards to the correct parts with pieces of yarn – a fun way to decorate a tree. Take extra cards and draw any parts that are missing, such as flowers, nuts or fruit. Add those to the tree where they might be found. Older children can discuss the function of each of the parts, such as roots hold up the tree (support) and bring water into the tree. (Scissors speed up card removal when you are finished.)

Sketching trees is a good way to learn the shape of different kinds. Claire Walker Leslie has an excellent guide to sketching trees (click on the Guide to Tree Sketching resource to download a .pdf file). Sketch a tree and label the parts if you can’t go outside.

IV. How Trees Grow – The Internal Parts of a Tree

See if you can find a “tree cookie,” a cross-sectional piece of wood through a tree trunk. These are often available at craft stores. Those with the bark still on are the best.

Internal parts of a tree:

• cambium – layer of active cells that divide to form inner bark and sapwood
• sapwood
• xylem – water carrying elements (in sapwood)
• phloem-food carrying elements (inner bark)
• heartwood

Look at the tree cookie and see how new rings are added each year. Explain how the tree only grows from the cambium and cutting it (for example by carving initials on a living tree), damages its ability to grow and live. A fun demonstration of how a tree grows might be to add layers of clothes to a doll or person, to show how the tree expands by adding layers. See if you can tell how old the tree that made the tree cookie was when it was cut down by counting the rings. (More information on internal parts).

We’ll continue with more activities next week. Until then, here are two sources of more information about trees:

Illinois Department of Natural Resources has  lesson plans in .pdf format

Arbor Day Foundation has education links and online games.

Hope you enjoy our celebration of tees this month. If you have any suggestions for activities or websites, please let us know.

1. Ice Spikes

Have you ever seen bumps or spikes come up from the ice cubes in your ice cube tray? SnowCrystals.com has a great discussion of ice spikes, how they form and how to grow some of your own. For more pictures and a movie, try Spikes on Ice Cubes.

2. Ice cube rescues

Give your child(ren) a challenge to “rescue” ice cubes floating in a glass of water with only a piece of string and some salt. Then watch this video to see how it is done.

3. Freezing and thawing water

Freeze water in various-sized containers and then set the ice “sculptures” out to thaw. (Set them in in deep bowl indoors or outside on a sidewalk or patio where a little melt water won’t matter.) Time how long it takes various sizes and shapes to melt with a watch or clock. Does size or shape influence melting time? How?

Try freezing a water-filled water balloon (set in a bowl first). Once it is frozen, what happens when you toss it? What happens when you freeze a balloon filled with air in a bowl of water?

4. Floating and sinking

Create an ice cube boat and float it to emphasize that ice is less dense than water.

Gather:

• ice cube tray
• cold water
• pie plate or shallow bowl
• plastic wrap
• toothpicks
• triangle of paper
• clay (optional)

Fill the ice cube tray with water. Cover the tray with a tight layer of plastic wrap, which will hold up the toothpicks. Stick a toothpick in the center of each cube, enough so that there is a least one for each child. When the ice cubes are frozen, remove from the tray. Insert a small triangle of colored paper on each toothpick to make a sail, and float the ice cubes in a bowl of cold water (the colder the better). Do the boats float? Do they stay upright? If not, try adding some clay to the bottom until the ice cubes are balanced. (This may be difficult at first, if the oily clay doesn’t stick to the wet ice. I found it did work with patience.)

5. Moving on to dry ice

Dry ice (frozen carbon dioxide) is available at many grocery stores. Just remember that it is much colder than regular ice and will require special handling. Always use gloves, and tongs are a good idea too. Never put dry ice in a swimming pool!

See this Steve Spangler video for some ideas and handling suggestions.

Ice is so much fun to experiment with in the summer. Let me know if you have any other experiments to do with ice or activity tips.

For more information, try these books:

and these related subjects:

Ice Scientist: Careers in the Frozen Antarctic (Wild Science Careers) by Sara L. Latta

Pioneering Frozen Worlds by Sandra Markle

Even if you don’t want to participate, take a look at the Parents and Educators section for information and activities that you might find useful.

You may have heard on the news that honey bees are disappearing. The Hive Detectives follows the research of four scientists trying to figure out what is going on, as well as discussing a lot of general information about honey bees.

In the 1990’s I co-authored a set of lesson plans about honey bees, called “Africanized Honey Bees on the Move” for the University of Arizona. At the time the Africanized honey bees had just moved into Arizona, and many people were concerned about them. The lesson plans have a number of hands-on activities to do with many aspects of honey bee biology. If you go to a grade level, it will list appropriate lessons. Each lesson has links to activity and information sheets. Many of the lessons can be adapted to mixed-age groups.

Here are some honey bee-related activities and links:

1. Gardening for bees

Honey bees require pollen and nectar from flowers in order to survive. One simple activity is to investigate what kinds of bee-friendly plants grow in your area and have your children design and plant a bee garden.

You may wonder if encouraging honey bees to visit flowers in an area with children might be dangerous. It turns out that bees collecting food, called foraging bees, are not likely to sting unless they are stepped on, caught or otherwise threatened. This might not be an appropriate activity, however, for children who are allergic to bees.

(The first two websites were recommended in the book).

Pollinator.org has planting guides to help you find appropriate plants.

The Haagen-Dazs help the honey bees website has simple instructions for a bee garden, as well as funny videos.

What can the layperson do to help the honey bee has a lot of practical information about gardening for honey bees and other things you can do to help honey bees.

And don’t forget the Great Sunflower Project mentioned in a previous post.

These flowering plants help all kinds of pollinators, not just honey bees.

2. Honey bees and water

Any idea what these bees are doing?

Honey bees need a lot of water, especially in the summer. They use the water to cool inside the hive, to prevent the wax honeycomb from melting. You can see the tongue, called a proboscis, sucking up the water at the edge of this lily pad.

Getting water can be dangerous business for a honey bee. Honey bees often end up falling in, like the ones you see in swimming pools. Can you design a safe place for honey bees to gather water to add to your garden?

3. Honey bee communication and dances.

One of my favorite lessons was always doing the honey bee waggle dances as a way of learning how honey bees communicate.

Dancing under a polarized sky also has a lot of information about honey bee dances.

4. Honey bee senses

Honey bees perceive the world in a way that is very different from humans.

Honey bee senses lesson

What a bee sees

5. Honey bee and other bee nests

Investigate where honey bees live, where beekeepers keep bees and what it is like inside a hive.

The Insect Architects post has a some information about honey bee homes.

You can supply nest sites for other kinds of bees.

I don’t know whether you can read it, but the sign says “Digger Bee Nest Site.” We have left a patch of soil for the tiny digger bees to nest in.

The solitary and social bees lesson has a explanation of the different kinds of bees and how to construct an orchard mason bee nest.

There are a lot of ways to use honey bees as examples for science and nature lessons. Please let me know if you would like more information about any of these activities or if you have found a great website that helps children learn about honey bees.

Books to help you find out more:

In addition to The Hive Detectives,

you might be interested in these other books about bees from a precious post:
For young children you might want to try The Magic School Bus Inside a Beehive

Are you a Bee? is an intriguing book that compares humans and honey bees in an informative and gently humorous way.

The Bumblebee Queen by April Pulley Sayre (Author), Patricia J. Wynne (Illustrator) is a positively gorgeous book, chock full of good information. Any child who is interested in bees will love this book.

A Country Year by Sue Hubbell has some interesting tidbits on keeping honey bees, although it is about many other aspects of the natural world as well. A few of the chapters can some information that could be considered adult, such as she briefly discusses her divorce. You might want to read it first to determine if it is suitable for your older children. I have to say my son and I love it and I read it to him almost every summer (a summer tradition).

Book of Bees by Sue Hubbell contains a lot more technical information about beekeeping. There are many other books about beekeeping available, but this one warms my heart because it also shows more of the human side of the experience.

Note: the book that inspired this post was found at our local library.

Dr. Geoffrey Marcy is an astronomer who hunts for planets around stars other than our sun. He and his team have found about half the planets discovered thus far.

According to the book, Dr. Marcy became interested in outer space when his parents gave him a telescope at 14. He climbed out the window to the patio roof with it. One look into the night sky, and he was hooked on astronomy.

Dr. Marcy pioneered a technique to look for planets that involves the use of a spectrometer, which gathers and measures light from stars. Let’s celebrate the book by taking a look at some of the science behind his techniques.

1. Activity:  Make a rainbow

One of the easiest ways to study how the light we see is made up of a mixture of colors (or light of different wavelengths), is to create a rainbow using water.

Robert Krampf has a video to show us how with a hose. (If you have never tried his Happy Scientist website, it is well worth a visit.)

Another device that can be used to separate light into its component colors is a prism.

This prism is made of glass. You can find them at teaching or science supply stores. When the light passes through it, we can see this on the ground:

For best results I put a piece of white paper on the ground in a shaded area, and held the prism about three or four feet away in the direct sunlight. With practice you can find and direct the resulting rainbows by rotating the prism.

If you don’t have a prism, the grooved side of a CD can separate colors in light as well. CD’s act as what are called “diffraction grids.”

2. Activity:  Make your own spectrometer from a cereal box. (Requires adult assistance)

What is a spectrometer? Is it different from a spectrophotometer?

A spectrometer is a device that gathers light from a source and divides it into a spectrum by passing it through a medium. Those used for astronomy would have a telescope to gather the light, some sort of device to separate the colors – such as a prism or diffraction grid – and a detector to record the results. Sometimes gases or solutions are added for the light to pass through to help gather additional information about the characteristics of the light.

There’s a more detailed explanation at How Does a Spectrometer Work?

A spectrophotometer is simply a specialized spectrometer that works with light near or in the visible spectrum for humans.

To make a spectrometer using a cereal box,

Gather:

• an empty cereal box
• sharp knife (ask an adult to help with this part)
• empty rewritable CD
• masking tape
• scissors

Seal the top of empty cereal box with masking tape, so no light can enter. Lay the cereal box on one of its narrow sides. Ask an adult to cut a slit across the bottom of the box, about 1 inch down from the top side. Some of the instructions suggest reinforcing the slit with masking tape. Ours worked okay without doing that, but if your box tears, you will need to fix it.

Take a look at these websites for additional diagrams and information:

A fresh look at light: build your own spectrometer

How to Make a Color Spectrometer From a Cereal Box & CD
at eHow (site has ads)

Leaving the box on its side, turn it to the other end. Have an adult cut a diagonal slit at about an 60 degree angle from the top, towards the middle of the box. This groove will hold the CD at an angle. Then cut the CD in half with the scissors so it will slip into the groove. Be careful, the CD may shatter. Put 1/2 the CD in the groove, shiny (reflective) side up.

The last step is to cut a viewing window. With the CD in place, cut a square opening at the same end of the box so that you can look down onto the tilted CD to see the colors.

To test your spectrometer with a flashlight, take it into a room that can be made dark. Turn the flashlight on to shine into the light slit and then turn off the room lights. Look into the viewing hole. If you don’t see a rainbow of colors, adjust the flashlight and or the angle of the box until one appears. You may now want to check the color spectrum of other light sources.

3. The Doppler Effect

When Dr. Marcy and his team study the light from stars, they are looking for evidence that the star is wobbling due to the presence of a nearby planet. Evidence of wobble comes from shifts in color due to the Doppler Effect.

Here is a video that explains how the Doppler Effect works.

Wasn’t that fun?

Next time you hear about a new planet being discovered some distant star, think of Dr. Marcy and his team. And if you know a child who is interested in science, particularly astronomy, then you should check out this inspiring book.

Book supplied by author (see disclosure page).

A. Is it honey bees or honeybees?

When in graduate school, I learned a convention from Dr. Roger Morse for insect names (I have since learned the idea originated with Robert E. Snodgrass). The insect names that are taxonomically correct, such as honey bees are actually bees, should be written as two words. Insect names that are not accurate in identification are given as one word. For example, whiteflies are not really flies, but are relatives of aphids, and thus should be one word.

Quiz (answers at the bottom of this post):

Pick the correct common name according to this convention:

1. Butter fly or butterfly?

2. Crane fly or cranefly?

3. Dragon fly or dragonfly?

4. Lady bug or ladybug?

5. Leaf-footed bug or leaf-footedbug?

Photo from Wikimedia

6. Bumble bee or bumblebee?

The convention is only a rule of thumb, however, because there are definitely exceptions:

Photograph by Craig Pemberton. Wikimedia

Although this creature is really a wasp, it’s common name is velvet ant (2 words).

B. Mantis or mantid?

This distinction is more difficult. I had learned that either is correct, that is the two terms are interchangeable. There is, however, a growing convention that mantis only be used for the insects of the genus Mantis, and that all others be called mantids. (Whitney Cranshaw, Colorado State University).

I personally like to use mantids for the plural, it is just easier.

For a searchable list of common names for insects of North America, see the Entomological Society of America

Let me know if you have any questions about insect names or would like to learn more.

Answers:

1. butterfly

2. crane fly (two words)

3. dragonfly

4. ladybug (Note: if you use beetle, then it is two words,  lady beetle or ladybird beetle)

5. leaf-footed bug (2 words)

6. Bumble bee (2 words)

The first place that Latin and Greek influence is obvious is in the scientific names.

Each species has a scientific name. The scientific name consists of the genus name, which is capitalized, followed by the species name, which is in lower case. Scientific names are often based on Latin or Greek words and are therefore printed in italics in typed works, or underlined (the editor’s mark for italics) in handwritten works. An example of a scientific name is Apis mellifera, the honey bee. In this case Apis is the Latin word for bee, melli- means honey and -fera means carrying or bearing.

Why not just use common names? Sometimes a common name denotes a single species, like Argentine ants, but other times a common name can represent a group of species with some common characteristic, like most of the ant species of the genus Camponotus are called carpenter ants. In a few cases the common name may stand for a group of species that are not even closely related, such as the army ants, which are identified by their behavior. Another problem is that in different areas of the world, several different common names may be used for the same species or group of species. For example, leafcutter ants may also be called parasol ants, grasscutter ants or fungus-gardening ants, and the queens may be called “big-bottomed ants.” This can lead to errors in identification and lots of confusion.

If you are interested in learning some Latin names for animals, Bestiara Latina has a list of Latin animal names with links to photos and, if you are really interested in learning Latin, fables about the animals. Try Cygnus, for example. if you learn that cygnus is Latin for swan, you will have no trouble finding the constellation of that name or remembering that cygnets are young swans.

Not all scientific names are based on Latin. The Greek word leuko means white. Knowing that will help you figure out that leucocytes are white blood cells, and the species name leucocephalus, is referring to white-something. If you add your knowledge that cephalus means “head,” you won’t be surprised to learn that leucocephalus is the species name of our white-headed bald eagle.

More interested in plants? About.com has What Do Flower Names Mean? If you skip to the second page, you will find that a multiflora rose is simply one with many flowers.

Back to Arbor Day, it turns out that Arbor is the Latin word for tree. Many other words share the same root, such as “arboretum.” For a list, see the derivatives of the Latin word, arbor. The same site offers a Latin Word of the Week blog. If your child wants to become a scientist, it might be worth subscribing.

One of our favorite names is nasturtium, which we learned means “nose-twister” in reference to the pungent odor of the flowers.

If you found this topic useful and you think your children might want to learn more about Latin and Greek roots in science, please let me know. It would be fun to delve more into this.

And if you have found interesting resources discussing scientific Latin and Greek, I would love to hear about them.

A new book, Bugs and Bugsicles: Insects in the Winter by Amy S. Hansen and Robert C. Kray (illustrator) gives us the answers for a number of common species of insects and a few uncommon ones, too (see review at Wrapped in Foil).

What happens when we get cold? We put on more clothes, and our bodies work extra hard to produce more heat. We may even shiver. Insects can’t do those things as easily, and are thus susceptible to cold and freezing. They do have some “cool” strategies to get through the winter, though.

Activities:

1. Pick an insect and investigate its life cycle.

Each kind of insect has a unique life cycle. By investigating the stages an insect passes through, you can figure out which stage or stages the insect is in during the winter.

Insects may overwinter as eggs, which are small and resistant to drying out. Other insects overwinter as immatures, called “nymphs.” As you will see below, there are insects that go through the winter as larvae. Others, such as moths, may stay cozy in protective cocoons and overwinter as pupae. The remaining insects spend the winter as adults, often hidden in cracks and crevices, such as in the bark of trees.

A few insects and insect relatives seem to defy their cold-blooded roots and can be found active in the winter. One example are the snow fleas, a type of springtail or collembola. We once spotted the tiny black creatures hopping across the snow while we were cross-country skiing. Wow!

If you are interested in ants, check out Where do ants go in the winter? at Wild About Ants. One species is called the “winter ant.”

Monarch butterflies are interesting insects because they fly long distances, or migrate, to avoid the winter cold.

This is a video about overwintering monarch butterflies. It is a trailer for the Discovery Channel show Life. Note for parents of sensitive children: the video does show birds eating butterflies and a butterfly covered with frost (presumably dead).

Have monarch butterflies appeared where you live yet this year?

2. Activities with acorns

We recently went to a talk by entomologist Mark Moffett and he told us about insects that spend their lives in acorns. He said that if you put acorns in a container of water, the ones that float are likely to have critters inside. The most common insect found inside an acorn is the acorn weevil. Ants, moths, and flies sometimes use acorns for homes too.

Video from National Geographic showing the life cycle of the acorn weevil.

Note to parents of sensitive children: This video shows a predator eating an acorn weevil larva. The larvae spend their first winter in the acorn and theier second winter underground as pupae.

See more acorn activities at  Acorns for Rent

3. Examine the properties of water when it freezes.

Living cells are full of water. What happens to water when it freezes, such as during the winter?

Bugs and Bugsicles has two hands-on experiments in the back to help children explore the freezing process.

The author also discusses how one insect uses a special strategy to get through the super cold winters of the far north. Without giving away all the details, let’s just say it involves antifreeze. And bugsicles!

This book was provided by the author.

For more information:

Bug Info “Where do insects go in winter?” – Smithsonian Institution Encyclopedia

Winter Hideaways at the University of Kentucky

Where do bugs go in winter? at About.com