celebrating nature, inspiring good writing
This summer, you may be able to observe an amazing event in nature. You can watch a small animal build a structure much bigger than itself, using materials from inside its own body!
This is what happens when a spider spins a web. Inside a spider are glands that can produce seven different kinds of silk. The silk comes out of little spigots, called spinnerets, at the rear of the spider's body.
A strand of spider silk is stronger than a similar strand of steel, and spiders use this amazing material in many ways. If they catch an insect, they may wrap it in silk, to eat later. Female spiders enclose their eggs in a silken sac to protect them. And some spiders—almost always females—make webs that are death traps for insects.
Webs can be in the shape of funnels, sheets, or domes, but the best-known are called orb webs. From an orb web's center, lines of silk radiate out in all directions, like the spokes of a bicycle wheel. After building this basic structure, a spider goes round and round, laying down ever-bigger circles of silk. Some of the silk threads have sticky glue to catch a moth or other prey. A spider can create this whole complex design in an hour or less.
When an orb web is complete, some kinds of spiders wait right in the center. Others hide at an edge. Either way, the builder keeps a front leg in touch with the web. Vibrations from the threads tell a spider whether prey has been caught.
Spiders often have to repair their webs, and some species routinely build a new one every day. And they recycle! They eat most of their old web. After digestion, it becomes brand new silk for the next construction job.
You may be able to watch a spider on the job. Look for webs in a field, park, or backyard. Also look for webs near doors, windows, or on a porch. The nighttime lights from such places attract night-flying insects, and spiders often build webs there. They may or may not be orb webs, but watching any kind of spider at work on its silken insect-trap can be fascinating fun.
And remember: the spider wants nothing to do with you. It is just trying to stay safe and catch some food.
This video was shot by Ingrid Taylor, " I shot this a few minutes after the rain subsided, when the City of Spiders outside the door came to life. Mass web-building and repair going on..." wikimedia commons
Scorpions are cousins of spiders but they are very different. Learn how they are strange and wonderful in Laurence Pringle’s book.
MLA 8 Citation
Pringle, Laurence. "Watch a Webmaster at Work!" Nonfiction Minute, iNK Think
Tank, 14 June 2018, www.nonfictionminute.org/the-nonfiction-minute/
Dorothy Hinshaw Patent
Nature's Animal Ambassador
If I asked you what grain is the most harvested in the world, you’d probably answer either wheat or rice. But the answer is actually corn, more accurately called ‘maize.’ This nutritious crop that originated in Mexico feeds not only people but also animals around the world. We’re used to the wonderfully tender sweet corn harvested in late summer and early autumn, but most maize is actually field corn, more starchy than sweet and used as animal feed or to make cornmeal and flour.
For a long time, biologists puzzled about the origins of this important crop. There is no wild plant that looks anything like modern corn, which is actually a giant grass. The closest relative is a scrawny branching plant with hard dark seeds called teosinte. It seems a huge jump from teosinte to corn, yet geneticist George Beadle found in the 1930s that corn and teosinte have the same number of chromosomes and could be crossbred to produce hybrids. With the limited tools available at that time, Beadle deduced that only about five genes were involved in creating the differences between teosinte and corn.
Fast forward to modern times, when scientists can look directly at DNA and analyze every detail of its structure. We now know that Beadle came very close to the truth—about five regions in the DNA seem to control the major differences between teosinte and corn. For example, these two plants look so very different, yet just one single gene turns a branched plant into a single stalk, like a stalk of corn. Another single gene controls one of the most dramatic and certainly most important traits for farmers—the nature of the seeds and their stalk. In teosinte, each seed has a hard covering. Just one gene eliminates the hard covering and produces a stalk bearing exposed seeds, like an ear of corn.
Scientists now use maize as a perfect example of two major ways evolution happens. One way is through major sudden jumps, like the change from a branching plant to a single stalk. The other is the more gradual kind of change that has led to the thousands of different kinds of maize grown by farmers today. There are probably hundreds of varieties of sweet corn and thousands of varieties of field corn. Think about that the next time you bite into a nice crunchy taco made from a corn tortilla.
Corn was a very important crop for homesteaders in the American West, used both to feed themselves as well as their animals. Read about it in Homesteading: Settling America's Heartland, revised and expanded edition, Mountain Press, 2013.
Dorothy Hinshaw Patent is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.
MLA 8 Citation
Patent, Dorothy Hinshaw. "Amazing Maize." Nonfiction Minute, iNK Think Tank, 8
June 2018, www.nonfictionminute.org/the-nonfiction-minute/Amazing-Maize.
celebrating nature, inspiring good writing
Almost every spring an amazing event in nature happens in parts of the United States. Huge numbers of insects called periodical cicadas emerge from the soil. For a few weeks they fill the days with loud buzzing calls.
Every summer you can hear the calls of some kinds of cicadas, but periodical cicadas are different. They exist only in the eastern two-thirds of the United States, and have the longest of all insect lives. Some periodical cicadas live 13 years, others 17 years, with nearly all of that time spent underground. Young cicadas, called nymphs, sip water and nutrients from tree roots. The nymphs count the years, probably by sensing changes in tree sap, as it is affected by the seasons of each year.
When their countdown ends and soil warms in the spring, millions of cicada nymphs dig out. They climb posts, bushes, and trees, and cling there. Their nymph "skins" split open and adult cicadas wriggle free. Finally, after many years underground, they are out in the sunshine. They can fly, and the buzzing noises of males attract females. It is a noisy and hectic time in their lives. They have just a few weeks to mate and produce the next generation. Once females lay eggs in tree twigs, all of the adults die. Soon after, tiny nymphs hatch from the eggs. They drop to the soil, borrow in, and begin to sip juices from tree roots. The nymphs grow slowly, counting the years until they will have their own time in the sun.
Nearly every year, one or more populations, called broods, of periodical cicadas emerge. Seventeen year cicadas live mostly in the Northeast and Upper Midwest. Thirteen year cicadas are most common in the South and Lower Midwest. Some broods emerge in parts of just a few states. Some years, a more widespread brood emerges in parts of fifteen states. Notice that I say "parts" of states. These cicadas don't roam around. The nymphs go underground in the same places where their parents emerged. You will find them in one town but not another, in one neighborhood but not another.
Some people call cicadas "locusts," but locusts are a kind of grasshopper that eats plants. Cicadas do not chew on plants. They are harmless, fascinating creatures. And, once in a great while, they give us a rare and awe-inspiring animal spectacle.
Visit the great website, Cicadamania, which has high praise for this book: "Definitely the best cicada book for kids. Adults will appreciate it as well, as it is well written, factually accurate, and beautifully illustrated."
You can read more about Larry's fascination for these creatures on his website.
MLA 8 Citation
Pringle, Laurence. "Here Come the Cicadas." Nonfiction Minute, iNK Think Tank,
23 Apr. 2018, www.nonfictionminute.org/the-nonfiction-minute/
It was December 24, 1801, when bundled-up Philadelphians bought their 25¢ tickets and entered Peale’s Museum on Fifth Street. Once inside, they saw the owner’s paintings. And I’ll bet you have too—even if you’ve never heard of Charles Willson Peale. This one, for instance, of his fellow Revolutionary War soldier:
Visitors to the museum had seen Peale’s collections of butterflies, too, and other nature specimens, such as the fossilized teeth of mysterious beasts. (Who knew then that animals went extinct? Hardly anybody!) But on this extra-special Christmas Eve, people probably hurried past Peale’s handmade dioramas, with the lifelike bodies of birds and mammals that he’d stuffed and posed. Today, Mr. C.W. Peale himself was introducing his NEW ATTRACTION. People had paid an extra 50¢ just to see it! Now they looked up, up, UP at it, and were astonished.
What animal’s skeleton was eleven feet tall? Seventeen and a half feet from its bony tail to the tips of its giant, curving tusks? It was a mastodon.
No one had seen a live mastodon in more than ten thousand years. So how did one’s bones get to Philadelphia? Mr. Peale and other naturalists such as Thomas Jefferson, the new President-elect, wrote to one another about their studies, collections, and the latest discoveries, such as like these huge, mysterious bones in southern New York state. Some of North America’s long-gone mastodons ended up there, by the Hudson River. As soon as he heard about them, Peale hurried to see them. Then he not only figured a way to dig up the bones, but he also painted a picture of the huge excavation!
Peale’s son, Rembrandt helped to draw and assemble the bones:
For years, people paid to marvel at the enormous, sensational skeleton. Later on, after Mr. Peale’s death in 1827, his museum slowly went broke. P.T. Barnum, the circus showman, bought a lot of his exhibits. Later still, they were destroyed in a fire. And the mighty bones of the mastodon wound up lost for a hundred years, until the skeleton turned up in Germany, where you can see it today.
In Thomas Jefferson, her sixth presidential biography for National Geographic, Cheryl Harness illuminates the many sides of Thomas Jefferson: scientist, lawyer, farmer, architect, diplomat, inventor, musician, philosopher, author of the Declaration of Independence, founder of the University of Virginia, and third president of the United States. Readers meet this extraordinary man of contradictions: a genius who proclaimed that "All men are created equal" and championed the rights of "Life, Liberty, and the Pursuit of Happiness," while at the same time living a life that depended on the enforced labor of slaves.
MLA 8 Citation
Harness, Cheryl. "The Big Deal in Mr. Peale's Museum." Nonfiction Minute, iNK
Think Tank, 18 Apr. 2018, www.nonfictionminute.org/the-nonfiction-minute/
Science through the lens
Do you know about the “birds and the bees?” If you don’t, don’t worry. You will learn soon enough.
When it comes to flowers there’s nothing to hide. There’s just no way around it—flowers are sexy. Their colorful, curvy petals are soft as velvet and as fragrant as the most expensive perfumes. Their nectar is as sweet as…well, honey. Besides being pretty, flowers have power. Their pollen is packed with protein. No wonder the birds and the bees, and insects of many kinds, find them so irresistible.
Pollen may be the perfect food for bees, but it is also the way plants get together. Think about it. Plants can’t walk, crawl, swim, or fly. So, how does boy meet girl?
In order to reproduce, the pollen from the male has to have direct contact with the female (and I don’t mean texting). Pollen grains are carried on the legs of bees and in the beaks of birds, from one flower to another. A few grains become engaged, hitched, and literally stuck on the sticky female flower part called the stigma. Sugar from the stigma fuels the pollen grain to sprout a tube. This pollen tube grows downward through the female part called the pistil and into the chambers that contain tiny bubble shaped eggs. When the tip of the pollen tube finally reaches an egg chamber it releases a male sperm cell. The sperm and the egg unite, and a brand-new cell is formed. This is the beginning of a seed.
Picture an apple. Before the apple was a fruit containing seeds, it was a very sexy flower. So the next time someone asks you if you know about the birds and the bees, tell them about flower power. They might be surprised how plants get together to make baby plants, which in scientific terms is an interesting example of the process called sexual reproduction.
Pollen is contained in the anthers, which are the six slipper shaped sacs at the end of the stamens. The female stigma is the rounded tip located at the top of the style. The pollen tube is a microscopic tube that grows through the style and into the ovary, which is hidden inside the base of this flower. Hanging down, at the lower right side of the photo are the remains of another flower. The petals and stamen have fallen off revealing the entire pistil: the stigma, style, and the ovary (green structure), which holds the eggs. Photo credit © Alexandra Siy
Why not watch some web-spinners do their thing with the help of this stunning and superlative book by Alexandra Siy? You can read more about it here.
Alexandra Siy is a member of iNK's Authors on Call and is available for classroom programs through Field Trip Zoom, a terrific technology that requires only a computer, wifi, and a webcam. Click here to find out more.
MLA 8 Citation