Frogs By Rhonda Lucas Donald and Kathleen W. W. Kranking
S
C
H
O
L
A
S
T
I
C
FESSIIONA ONAL OOKS PROFESS BOOKS
N E W
Y O R K
•
T O R O N T O
M E X I C O
C I T Y
• •
L O N D O N N E W
D E L H I
• •
A U C K L A N D H O N G
K O N G
•
S Y D N E Y
To Aggie, who taught me that it was okay for girls to catch frogs in the creek —R.L.D.
Scholastic Inc. grants teachers permission to photocopy the activity and pattern pages from this book for classroom use. No other part of this publication may be reproduced in whole or in part, or stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or o therwise, without written permission of the publisher. For information regarding permission, write to Scholastic Inc., 555 Broadway, New York, NY 10012. Cover design by Norma Ortiz Interior design by Solutions by Design, Inc. Interior illustrations by Patricia J. Wynne, except doctor on page 29 by Michael Moran Cover photograph by Nic Bishop from RED-EYED TREE FROG by Joy Cowley. Published by Scholastic Press, a division of Scholastic Inc. Photograph copyright © 1999 by Nic Bishop. Reprinted by permission. permission.
ISBN: 0-439-05178-9 Copyright © 2000 by Rhonda Lucas Donald and Kathleen W. W. Kranking All rights reserved. Printed in th e U.S.A.
Contents How to Use This Book: Welcome to Frogs! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
Background Background Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
Student Activities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Makes a Frog a Frog? (Critical Thinking, Science) .
. . . . . . . . . . . . . . . . . . . . . . . . . . .
11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
All in the Family (Critical Thinking, Science). Frogs on the Map (Geography, Mapping) . Tadpole Tadpole Transformation (Art, Science) Frog Walk (Movement, Science) .
Frog Olympics: Long Jump (Math, Science) .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
Webbed Feet Are Neat (Science) Stuck-Up Frogs (Science) .
11
Croak of the Wild (Language Arts, Science) .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
What’s in a Name? (Language Arts, Science)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
Leap-Frog Pop-Up Card (Art, Language Arts, Science)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
Warning Colors (Art, Math, Science) Tongue Zapper (Science)
Amphibian Aviators (Science)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Lily Pad Press (Critical Thinking, Language Arts, Science) .
18
. . . . . . . . . . . . . . . . . . . . . .
20
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
Frog Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
Student Reproducible Pages
= Activities with student reproducibles
How to Use This Book Welcome to Frogs! Take a leap into learning about frogs! These remarkable creatures are sure to fascinate kids with their unique life cycle, interesting eating habits, special survival strategies, and impressive athletic abilities. This complete resource includes background information, creative cross-curricular activities, and handson reproducibles—everything you need to help kids learn about and appreciate these amazing amphibians. Before you get your feet wet, here are a few tips for using this book.
1. Find out how many frog fans there are in your class. Ask students how they feel about frogs before you begin studying them. Do they think frogs are slimy? Do they think that frogs will give them warts? Have any of your students ever observed a frog or tadpole up close? Have they heard frogs singing? Ask children what they would like to learn about frogs. Once you have completed your frog studies, poll students again. What’s the most interesting thing they learned about frogs? What do they like best about frogs?
2. Choose activities that are right for your curriculum and your students. Before you begin your frog unit, look through the activities and choose the ones that connect with your students’ interests and learning styles, as well as the content areas you want to teach. Feel free to adapt, amend, or develop spin-off projects to meet the needs of your students as you see fit.
3. Encourage kids to read about frogs. Gather plenty of fiction and nonfiction books about frogs to develop students’ interest. You’ll
4
find suggestions throughout the activities section on pages 11–20. Book Breaks provide brief reviews of frog books, along with suggested activities. Also refer to the list of frog resources at the end of the book, including books for students and teachers, videos, kits, and Web sites. Sharing these resources with students will heighten their interest and deepen their knowledge of these critters.
4. Join the Frog Force. As your students will learn, many frogs are in danger of extinction. Other frogs suffer from deformities, the causes of which scientists are still investigating. (See “Frog Mystery” in The Lily Pad Press on page 29.) Your students can help frogs and the scientists studying them by participating in Frog Force, a program in which kids monitor frogs in their area for malformations. Frog monitoring is a great way for students to study frogs in their natural habitat. Plus they’ll be contributing information that may help save frogs. To learn more about Frog Force, go to the program’s Web site at www.frogweb.gov. There you’ll find instructions for monitoring frogs, rules for “frogging,” and forms for reporting what you find. The kids will need to be well supervised when monitoring frogs to be sure they don’t inadvertently harm them. Joining the Frog Force can help you turn your study of frogs into “real” science.
Background Information Jump Into Frogs!
Leading Double Lives
The throaty sound of frogs croaking at night is familiar to almost everyone. But there’s a lot more to frogs than croaking! Frogs are champion jumpers, amazing climbers, and skilled hunters. Some are as flashy as works of art, while others are so well camouflaged that they can disappear into their surroundings in the blink of an eye. Frogs can be tiny or huge, slimy or dry, poisonous or harmless. But one thing’s for sure: They’re never boring! Almost 3,500 species of frogs exist in various habitats, from rain forests to marshes to deserts—nearly everywhere except oceans and the North and South poles. Frogs have been popular subjects of myths and legends throughout history. The ancient Chinese believed that the entire world sat on the back of a huge frog whose movements caused earthquakes. The ancient Egyptians worshipped a frog goddess named Heket, who had a woman’s body and a frog’s head. Frogs were at one time thought of as evil creatures that helped witches, but they have also been believed to have curative powers. They have figured prominently in both fairy tales and popular culture, from the story of “The Frog Prince” to Kermit the Frog.® With their plump bodies, bulging eyes, and somewhat comical expressions, frogs have won fans throughout the world.
Frogs belong to the group of animals called amphibians, a word that means “dual lives.” This refers to the fact that frogs spend part of their lives as tadpoles in water and part as adults on land. Two other groups of animals are amphibians as well: salamanders and newts, and a group of wormlike animals called caecilians (see-SIL-ee-uns). So, what features Frogs take make an in about a amphibian quarter of an amphib the oxygen ian? First of they need through all, amphib their skin. ians have moist skin. Most frogs need moisture to keep their skin from drying out. Although frogs have lungs with which to breathe, they also take in some oxygen through their skin. Their skin must be moist in order to absorb the oxygen. Frogs that live in dry climates such as deserts usually stay out of the sun during the day. They burrow into the ground or hide under logs or rocks, coming out during the cool, damp night. The second feature of amphibians is that they are cold-blooded. Being cold-blooded doesn’t mean amphibians actually have cold blood, of course. It means that they can’t generate enough heat to keep their bodies at a constant temperature. To maintain a body temperature warm enough to allow them to be active, amphibians must lie in the sun or in warm water. The third feature of amphibians is that most of them lay shell-less, jelly-covered eggs, usually in water. Some frogs lay thousands of eggs at a time. The clear jelly covering protects the developing embryo inside.
Frogs were hopping the earth long before dinosaurs existed.
KERMIT THE FROG is a trademark of Jim Henson Company, Inc. All rights reserved.
5
What About Toads? You might be wondering where toads fit into the picture. Some people think that frogs and toads are separate types of animals, but toads are actually a kind of frog. They usually have drier, bumpier skin than other frogs, and most toads live on land instead of near water. But they are still frogs and, therefore, amphibians as well.
Frog Legs and Other Parts Frogs have a short, rounded body with no neck, a large head, and long, strong legs for jumping and swimming. Since their eyes and nostrils are on top of their head, frogs can hide underwater and still poke their head above the surface just enough to see and breathe. Frogs don’t depend on their senses of smell or hearing very often. They hunt mainly by sight, so their eyes are very large and contain sensors that detect even the smallest movements. Their irises come in many different colors—red, brown, black, silver, gold, Frogs don’t bronze, or drink water; green—and they absorb their pupils all the moisture can be round, they need through heart-shaped, their skin. or triangular. Frogs’ skin is covered with mucous glands; the mucus makes them slimy and keeps their skin moist. Some frogs’ skin contains poison glands as well, which ooze liquid that can be bad tasting or even deadly to enemies.
Frog Chow You won’t ever see a frog savoring its food. When it comes to eating, frogs are gulpers. Because they have such tiny teeth, they can’t chew their prey. Their big, wide mouth comes in handy to swallow prey whole.
6
Most frogs use their When sticky tongue zapping prey to grab food. with their The tongue is tongues, big attached at frogs can reach prey the front of farther than three the frog’s inches away. mouth rather than at the back like a person’s. When the frog sees a tasty creature it wants to eat, it flips its tongue out, grabs the meal, and pops it into its mouth—quick as a wink. As the frog swallows, its eyes sink down into its head to help push the food down its throat. A few kinds of frogs have very small tongues or no tongues at all. They catch their food by biting it or stuffing it into their mouth with their hands.
Frog leaping to catch food Some frogs eat only one kind of prey, whereas others will eat almost anything they can find. Frogs are hunters and always eat live food. Insects, spiders, worms, and ants are just a few frog favorites. Bigger frogs can handle bigger prey, including mice, rats, snakes, lizards, baby birds, fish, and even small crabs. Some frogs will gobble up other frogs as well.
A Nippy Nap
Pretty Poison
When wintry winds begin to blow in cold climates, many kinds of frogs settle in for a winter’s sleep. Frogs prepare for hibernation by digging into soil or even into the bottom of a pond, stream, or lake. While they are in this inactive, resting state, hibernating frogs use much less oxygen than active frogs and can take in the oxygen they need through their skin. Some frogs can survive even after being frozen almost solid! When spring comes, they thaw, dig out, and go about their froggy business.
While many frogs are colored to blend in with their environment, others really stand out. These flashy poison dart frogs use their vivid colors to send a message to predators: “Leave us alone—we taste awful!” A few species of these frogs produce some of the deadliest poison in the world. Most of these beautiful frogs live in tropical rain forests. They come in a rainbow of colors, including bright blue, yellow and black, green and black, red and blue, bright red, and brilliant yellow. The poison dart The biggest frog is frog got its the goliath frog, name from which grows as big the way it’s as a dinner plate. used by The smallest frog is certain a type of poison dart South frog that’s only a American little bigger than a Indians. grain of rice. When the Indians are hunting, they use blowguns to shoot darts at animals. To make the darts more effective, they cover them with poison that is produced in the frogs’ skin. Poison dart frogs don’t have many natural enemies. Most animals heed the warning given by the frogs’ bright colors. If an animal tried to eat one of these frogs, it would spit it right back out. Although such a quick taste probably wouldn’t be poisonous enough to kill the predator, the frog’s terrible flavor would teach the predator to avoid that type of frog in the future.
Tricks of the Trade When does a frog not look like a frog? When it looks like a leaf, a bud, or even a bird dropping! Frogs have an amazing variety of tricks to camouflage themselves, whether to avoid hungry enemies or ambush unsuspecting prey. Some frogs are shaped and colored like objects in nature to blend in with them. Asian horned frogs have pointed flaps over their eyes that look like leaf tips. Green tree frogs huddle their flat bodies against a branch to look like buds. The false-eyed frog puffs up its body when it’s threatened, showing two big eyespots that make it look like a fierce owl. Other frogs simply rely on coloring to match their surroundings. Green frogs disappear among leaves or grass, and brown frogs blend in with dark tree trunks or dead leaves on a forest floor. Many frogs have dark backs and light bellies, which can make them difficult to see in the water. To an enemy watching from above, the frog’s dark skin looks the same as the dark water. To enemies below, the frog’s light underside matches the sky.
Asian leaf frog
Blue poison dart frog
7
Froggy Athletes
At Ease in the Trees
If frogs could enter the Olympics, they’d probably hop away with some gold medals! These amazing athletes are some of the world’s greatest jumpers. Specially built for leaping, frogs have long, powerful hind legs that are mostly made of muscle. Their feet help “Flying” frogs can glide them jump as well; as far as 50 feet they bend easily through the air. for a springing launch and are even a little sticky to give the frogs traction for takeoff. In one quick movement— boiingg!—a frog can bound many times its own length. Frogs are incredible swimmers as well. Some frogs spend most of the time in the water; others may just jump in to escape an enemy. But they all swim like little powerhouses. Their strong hind legs bend and then kick, pushing through the water with big, webbed feet and propelling the frog forward. Under water, special eyelids called nictitating membranes function like goggles to cover the frog’s eyes, protecting the eyes and helping Frogs are the frog see.
When it comes to climbing, tree frogs are champion acrobats. These small and often colorful frogs live in trees, bushes, and reeds around the world. Their feet are the secret to their climbing success, with long, slender toes that wrap around even very thin branches or stems. Each toe ends in a sticky disk covered with microscopic bristles. These disks help the frogs get a grip on the slickest leaf or limb. Tree frogs can even climb up glass without slipping.
legendary leapers. The African sharp-nosed frog can jump farther than 16 feet in one hop. That’s more than half the length of a school bus!
8
Tree frog
Something to Croak About Besides their athletic talents, frogs are also famous for their calls. Male frogs call during the breeding season to attract female mates. They also call to tell other males to stay away from their “turf.” Each frog species has its own particular place to call from, such as ponds, swamps, or bushes. Each species also has its own specific call, which may be anything from whistles, grunts, or barks to clicks, buzzes, or squeaks. Sometimes a group of males will sing together in a mating chorus. Frogs call by using their vocal cords. First they take air into their lungs, and then they close their mouth and nostrils. Next, they move the air quickly back and forth between their lungs and mouth. The vocal cords vibrate as the air passes over them, producing sound. Many male frogs have elastic pouches of skin under their chin or near the sides of their
mouth. These vocal sacs inflate like balloons as the air moves into the frog’s mouth, making the calls louder.
Frog with vocal sacs inflated
From Eggs to Frogs Once a male and female frog of the same species find each other, mating takes place. First the male frog grasps the female from behind. As she lays her eggs, usually in the water, he sheds his sperm over them. Most kinds of frogs then leave the eggs on their own. Frog eggs are covered with a gooey jellylike substance. When the Some bullfrogs lay eggs are first over 20,000 laid, the jelly eggs at a is thin. As the time—more jelly absorbs than any other water, it type of frog. becomes a slimy, protective mass around the eggs. Some egg masses are huge, covering as much as five square feet. Though most
Frog eggs
frogs lay their eggs in clumps, others lay long strands or chains of eggs. After a few weeks, the eggs hatch and out swim tadpoles—legless creatures with a rounded body and a tail. Tadpoles’ lives are very different from the lives they will lead as frogs. They spend all their time in the water, breathing with feathery gills instead of lungs and feeding only on vegetable matter such as algae. But soon the tadpoles begin the process of metamorphosis, which means “changing shape.” They begin to grow legs and their bodies get bigger . Their tail starts shrinking until it disappears altogether, their gills are replaced by lungs, and they begin eating tiny water creatures. When metamorphosis is complete, the young frogs—called froglets— are small copies of their parents and are ready to leave the water.
Eggcentric Alternatives Not all species of frogs follow this typical pattern of reproduction. Certain species of poison dart frogs lay their eggs under leaves on the forest floor, and then one of the parents stands guard over the eggs. Once the tadpoles hatch, they get a “froggyback” ride on their parent. The parent climbs high up a tree until it finds a bromeliad flower, which usually holds a pool of rainwater in its center. The parent deposits the tadpoles in the pool, and there the tadpoles grow up! Other species have fancy tactics as well. The female pygmy marsupial frog tucks her eggs into pouches under the skin on her back,
9
carrying the backpacking babies there until they are ready to hatch. The male Darwin’s frog goes even further than that. He slurps up his mate’s eggs in his mouth, and they hatch and grow inside a sac in his throat. When they have grown into froglets, they hop right out of his mouth! But It doesn’t really the gastric rain cats and dogs, brooding frog of course. But has an even sometimes tiny more unusual froglets are method. She picked up by swallows her strong winds in a storm and newly laid eggs, rained down to and her young earth miles away. develop in her stomach. Once they have become froglets, she vomits them up! “
”
Frogs in Trouble In many places around the world, frogs are facing big problems. People destroy frogs’ habitats by filling in or polluting breeding ponds and by clearing land for farms, buildings, and roads. As frogs try to cross these roads to get to their breeding ponds, many of them are killed. Water pollution is another problem that frogs face, mainly due to chemicals from agricultural runoff. In dozens of states, people are discovering alarming numbers of deformed frogs. Some scientists believe that these deformities could be the result of water pollution from insecticide. Since frogs are considered good indicators of the health of the environment, scientists are studying the implications that these findings may have on human health.
10
Frog Medicine Scientists are discovering that frogs, especially some species that live in rain forests, can be valuable in helping cure human diseases. The poisonous or bad-tasting chemicals in the frogs’ skin actually have medicinal qualities. Rain forest tribes have used these frog remedies for hundreds of years. For example, scientists have discovered a type of frog from South America that gives off a chemical that can be used as a painkiller. The chemical is 200 times more powerful than painkillers used in hospitals now. Scientists have also found that Australian tree frogs produce a chemical that helps sores heal. Currently, a stomach-brooding frog from Australia is being studied for clues to a remedy for ulcer patients. Scientists think that many more discoveries will result from the study of frogs. Unfortunately, the rain forests where many frogs live are disappearing. As your students enjoy doing the frog activities in the next section, they’ll gain a new appreciation for these amazing aniMore than mals—and four-fifths of they’ll underall frog stand how species live in important it the tropics is to save and subtropics. such unique creatures.
Student Activities What Makes a Frog a Frog?
All in the Family (Critical Thinking, Science)
(Critical Thinking, Science)
Students identify the characteristics that are unique to frogs and color a frog picture. Make a copy of page 21 for each student. Show children pictures of different frog species and discuss the characteristics all frogs share: moist skin, wide mouth, large eyes and nostrils on top of the head, eardrums on sides of head, long hind legs, and long toes. Talk about how the frog’s shape helps it sur vive. For example, a frog’s strong hind legs help it jump, swim, or climb to escape predators or catch prey. Eyes and nostrils on top of the head enable a frog to stay underwater and still breathe and see. Ask students to color the frog on their handouts. Then have them draw lines from the words for each part of a frog to that part of the frog in the drawing. Ask them to draw an “X” through the words that don’t apply to frogs: feathers, scales, wings, and antennae.
Amazing Frogs and Toads by Barry Clarke, Ph.D. (Knopf, 1990), is an excellent resource to have in your classroom collection. It features numerous photographs and interesting facts about many kinds of frogs. Select a few of the frog facts and share them with the class to pique students’ interest. This book will come in handy for many of the activities in this guide.
Students distinguish between frogs and other amphibians and learn the meaning of the term amphibian. Make a copy of page 22 for each student. Explain that frogs are members of a group of animals called amphibians. The word amphibian can be broken down into two parts: amphi meaning “both” and bios meaning “life.” Amphibians do seem to live double lives: one as larva (tadpoles) and another as adults (frogs). The change from larva to adult is called metamorphosis. Amphibians are the only vertebrates that go through metamorphosis. Frogs look very different from their amphibian relatives—newts, salamanders, and caecilians. But they are all cold-blooded, have moist skin that can take in oxygen, and go through metamorphosis. Students may think that newts and salamanders look like lizards. Although they may resemble lizards, newts and salamanders do not have scales as reptiles do. Students may also think that caecilians look like snakes or worms. Again, caecilians do not have scales as snakes do and, unlike worms, caecilians have skeletons and teeth. After students have colored the pictures on page 22, direct them to draw a circle around the frogs, a square around newts and salamanders, and a triangle around the
Fire salamander
11
caecilian. Have kids mark an “X” over the animal that is not an amphibian— the chameleon. Talk about how frogs are similar to the other Orange amphibians (as striped newt discussed above) and how they are different. The most obvious differences are that adult frogs generally have Ornate horned frog plump bodies, no tails, and their hind legs are adapted for jumping. Help students fill in the blanks to spell the word amphibian . Common frog
ANSWERS: 1—spring peeper (frog), 2—fire salamander , 3—chameleon, 4—ornate horned frog, 5—caecilian, 6—common frog, 7—orange striped newt; The chameleon is a reptile, not an amphibian.
Frogs on the Map (Geography, Mapping)
Students use a world map to match frogs with their continents of origin. First cut seven frog shapes out of construction paper. (You may wish to trace the outline of the frog illustration on page 21.) Write one of these frog species on each shape: African reed frog, Asian painted frog, Australian gastric brooding frog, North American cricket frog, European common frog, and South American banana tree frog. Show students a world map and explain that a continent is what geographers call each of Earth’s seven main areas of land. Trace the outlines of the continents on the map and name them: Africa, Antarctica, Asia, Australia,
12
Europe, North America, South America. Point out where you live on the map and ask students which continent it is. Then ask student volunteers to place the frogs on the correct continents on the map. Tape or tack the frogs in place.
EXTENSION: Find out which species of frogs live in your state. Are any of them protected because they are rare? One way to find out about rare frogs in your state is to visit the U.S. Fish and Wildlife Service’s Web site at http://www.fws.gov/. Once at the site, go to the area on endangered species.
Tadpole Transformation (Art, Science)
Students make a paper tadpole puppet that turns into a frog and learn the meaning of the term metamorphosis. Make a copy of page 23 for each student. Begin by discussing a frog’s metamorphosis, the process of changing from a larva (tadpole) into an adult (frog). Meta means “change” and morph means “shape.” Show students pictures of frog eggs, tadpoles in various stages, froglets, and full-grown frogs. Explain that once the tadpoles hatch from the eggs, they have gills to breathe with and a long tail. Eventually, the tadpole transforms into a froglet, a small adult frog with four legs, no gills, and no tail. After kids have colored the frog and tadpole body parts on page 23, help them fill in the blanks to spell metamorphosis. Then help them cut out the pieces along the solid lines. (To make the pieces sturdier, glue them to thin cardboard before cutting them out.) The spots marked with an asterisk show where to punch holes for the paper fasteners. Guide students through the stages of assembling the tadpole and frog:
1
Attach the tail to the body as shown to make the tadpole.
Invite students to arrange puppets in various stages of frog development and line them up in the correct sequence. Frogs ( First Discovery Book ) by Daniel Moignot (Scholastic, 1997) will come in handy when discussing metamorphosis. The see-through pages and detailed art make the progression from egg to tadpole to frog easy for children to follow.
Frog Walk (Movement, Science)
2
Attach the two hind legs in the same place as the tail.
3 4
Attach the two front legs. Remove the tail to make the froglet.
Students imitate the walking and leaping patterns of frogs and participate in a relay race. Most children have played leapfrog, but have they ever tried to walk like a frog? In this game, they’ll get to do both. First, have kids practice leaping like a frog. For the purposes of this game, they won’t leap over each other as in traditional leapfrog. Instead, they’ll simply leap in a froglike way from a squatting position. Tell students that not all frogs get around by jumping. Some walk to where they’re going. To walk like a frog, a child should get on all fours. The left arm and right leg move forward at the same time. Then the right arm and left leg move together. Give children a few minutes to practice walking like a frog. Next, divide the class into teams. Each team member must walk like a frog to a turn-around spot, then leap back to tag the next “frog” in line. The first team to have all members complete the relay wins.
13
Frog Olympics: Long Jump
2
(Math, Science)
Next, have children hold a small plastic lid in their hands as they paddle. They should notice that they are better able to push through the water with the lid than with their bare hands.
Students compare frogs’ jumping ability with humans’ and other animals’ by making a graph. Frogs are pretty amazing athletes—especially for their size. Ounce for ounce, frogs outswim and out-leap humans. Frogs are even good gliders. To see how frogs measure up to other animals athletically, help children fill in the graphs on page 24. To make the graphs easier to read, children can use a different color for each animal athlete. Help students count by fives to make filling in the graphs easier. Have children imagine that it is time for the medals ceremony. Ask them which animal is the gold medal jumper. Point out that even though the kangaroo and person jump farther than a frog, a frog is actually a better jumper for its size. A frog can jump 100 times its body length, whereas a kangaroo jumps about nine times its length, and a person jumps just over five times his or her length.
Webbed Feet Are Neat (Science)
Students perform an experiment to see how webbed feet help propel a frog through water. Frogs that spend a lot of time in the water often have webbed feet that help them swim better. Ask children why they think webbed feet would help a frog. Then let them try an experiment.
1
Fill a sink, small aquarium, or deep dishpan about three-quarters full of water.
14
Have kids splay their fingers out and move their hand like a paddle in the water.
3
Explain that the lid functions in the same way as the webbing on a frog’s feet. The webbing acts like the flippers that divers wear. Ask children to name another animal that has webbed feet (duck, beaver, sea otter), and consider how webbed feet help those animals.
Stuck-Up Frogs (Science)
Students perform an experiment to learn about tree frogs and their adaptations for climbing. Life in the forest would be dangerous for tree frogs if they didn’t have special adaptations to help them climb and hang on to trees and leaves high off the ground. An adaptation is a physical characteristic that a plant or animal has developed to help it survive. One adaptation tree frogs have developed is circular disks on the tips of their toes that help them hang on to tree bark or leaves. The disks make the tips of tree frogs’ toes larger, so there’s more to hang on with. Plus, the disks are covered with tiny bristles and sticky mucus that allow the toes to adhere to even the slickest surface. With such neat feet, some frogs are able to walk up a vertical pane of glass. Help students understand how a tree frog’s toes help it climb and live in the forest.
1
Cut out several leaf shapes from paper. The shapes should be about five inches long and three inches wide.
2
First, demonstrate the experiment to the kids:
• Touch all five fingertips on one of the leaves to show that the leaf doesn’t stick to them. • Then dip the tip of each finger on one hand into petroleum jelly. There should be a fair amount of jelly on each finger. • Now touch the jellied fingers to a leaf and lift it. Explain that the sticky jelly acts like the mucus on a tree frog’s toes that helps it cling to leaves and tree bark.
3 4
Carefully supervising children, let them try to pick up leaves with jellied fingers.
If you don’t mind messy windows, you can let the kids cut out small paper frogs and smear petroleum jelly on one side. They can then stick the frogs onto your classroom window.
Croak of the Wild
will have one.) Put the slips in a paper bag.
2
Have each child draw one slip. On your signal, students should begin making their calls. You may wish to determine and demonstrate a desired noise level in advance. Have children move around the room to find others making the same call.
3
Once a student finds a match, the two should stay together and keep calling. When everyone has found a partner, collect the slips and play again so that kids get a chance to make other calls. Note: It’s possible that some students will not find a match.
“Croak of the Wild” is adapted from SuperScience magazine, February 1996.
Frogs and Their Calls barking tree frog: “arf! arf! arf!” (like a dog) bullfrog: “o-rum, jug-o-rum, o-rum” (very deep) cricket frog: “gick, gick”
(Language Arts, Science)
green tree frog: “hey baby, baby! hey baby, baby!”
Students listen to frog calls and play a frog-call game.
narrow-mouthed toad: “neeee! neeee!” (high voice)
One reason frogs sing or call is to find mates. But sometimes there are many species in the same area all singing at the same time. With so many singing frogs, it’s important that frogs be able to recognize members of their own kind. That’s why each species has its own special call. Familiarize your students with frog calls by imitating the sounds listed under “Frogs and Their Calls.” Practice making the calls with your students, and then play “Croak of the Wild.”
1
Make several copies of the list at right. You may wish to enlarge it on the photocopier. Cut the calls apart so that there is one call on each slip. (Make sure that there are enough slips so that each student
pig frog: “woink, woink, woink” (like a pig, very deep) spotted chorus frog: “wrrrank, wrrrank, wrrrank” (roll the Rs) spring peeper: “peep! peep! peep!” squirrel tree frog: “quank, quank”
In one of the five short stories in Frog and Toad Are Friends by Arnold Lobel (HarperCollins, 1979), Toad loses a button from his jacket. He and Frog look everywhere for Toad’s button, but they only find buttons that don’t match.
15
Sorting buttons is a fun activity in conjunction with this book. Bring in several buttons of different shapes and colors, but only one big, white, round button with four holes like Toad’s. Let children eliminate buttons that have the wrong characteristics until they are left with a button like Toad’s.
What’s in a Name? (Language Arts, Science)
Students match frogs to their names based on the frogs’ appearances.
half so that it is 8 inches by 5 inches. Keeping it folded, cut a slit across the center fold about three inches from the bottom edge. The slit should be approximately three inches across when the card is opened.
2
Open the folded sheet and gently pull the slit toward the inside of the card, as shown. Then press along the fold as you close the card, as shown. When you open the card now, the triangular fold should pop out slightly. Note: This step is tricky and may require advance preparation by the teacher.
Scientists sometimes name animals, including frogs, based on how they look. Distribute copies of page 25 to students and help them match the names of six different frogs with their pictures. Explain that they should read the clues and look at the drawings. When they are finished, go over the answers and show kids photographs of the frogs on the sheet. Ask children to guess how the frogs got their names.
ANSWERS: 1—glass frog, 2—duck-billed tree frog, 3—tomato frog, 4—Asian leaf frog, 5—false-eyed frog, 6—strawberry poison dart frog
3
Fold another sheet of blue construction paper in half. Use clear tape to attach this piece to the outside of the first piece. Note: Be sure not to tape near the
Leap-Frog Pop-Up Card (Art, Language Arts, Science)
Students make a pop-up card and complete a verse inside. Your students can send froggy greetings to friends with these fun pop-up cards. Note: Children will need your help following these steps to assemble their cards:
1
Fold an 8 - by 11-inch sheet of blue construction paper in
16
pop-out fold.
4
Reproduce page 26 and cut out the frog and the poem. Tape or glue the poem to the inside of the card on the right side. Color the frog and tape the frog’s left hind leg to the left side of the pop-out fold, as shown. Make sure the frog does not show when the card is closed.
5
Cut out a moon and stars from construction paper. Tape or glue them in place, as shown. When you open the card, the frog should appear to move toward the moon.
predators of their danger. In fact, some frogs that aren’t poisonous benefit from their bright colors because predators may not want to take a chance! Make a copy of page 27 for each student. Have children solve the equations to determine which colors to color the frogs. When they are finished, explain that all of the species shown are poisonous except the corroboree frog. It is an imposter posing as a poisonous frog! Have students research other brightly colored poisonous animals, such as yellow jackets and coral snakes.
ANSWERS: blue = 7, bright green = 5, red = 4, orange = 12, yellow = 8
6
After children have completed their cards, have them fill in the blank to complete the sentence: “If I could hop anywhere, I’d hop to ________.”
Tongue Zapper (Science)
Students make a toy that can catch prey in a way similar to a frog. “
Warning Colors (Art, Math, Science)
Students solve math equations to determine the colors of frogs on a color-in page. Students also learn about poisonous frogs. One of the ways some frogs protect themselves from enemies is by releasing poison from glands in their skin. The poison may cause the predator to release the frog. In some cases, the poison may even be strong enough to kill the predator. Poisonous frogs are often brightly colored, which effectively warns
”
Kids will love learning about frog tongues that are specially adapted to protract and catch prey at a distance. Show kids pictures of frogs using their tongues to catch prey. Then let them see how good they are at zapping prey the way a frog does. Here’s what to do:
1
Give each student a paper party favor, a copy of the fly shown here, and a small piece of self-sticking Velcro™ (with both a hooked side and a fuzzy side).
2
Carefully unroll the party favor and stick one half of the Velcro™ on the end, as shown. The Velcro™ must face away from the child when the favor is blown out.
Poisonous frogs
17
3
Cut out the fly and stick the other side of the Velcro to its body, as shown.
Amphibian Aviators (Science)
Students make a paper parachute to illustrate how frogs like the Costa Rican flying frog glide.
4
Place the fly within reach of the extended party favor, with the Velcro™ side facing the child. Children should blow on the favors and try to catch the flies. Kids might even try to toss up the flies and catch them in midair—just as a real frog might!
Explain that a frog’s tongue doesn’t work in the same way as the party favor. Muscles at the base of the frog’s tongue snap it out and pull it back in. And instead of Velcro™, a frog’s tongue is coated with sticky mucus. It’s Mine by Leo Lionni (Knopf, 1985) features a trio of greedy frogs that each want to claim everything on the island where they live as their own. It takes a big storm and a friendly toad to make them realize that sharing is better than being selfish. This book is a good introduction to fables. Explain to students that a fable is a story meant to teach a lesson, and ask them what the lesson is in It’s Mine. Lionni uses paper cutouts to illustrate his stories. Let your kids try their hands at making pictures using paper cutouts.
18
Most people think of frogs as jumpers, but they are also excellent diggers and climbers. And a few frogs are “fliers.” Although they are called flying frogs, these frogs actually glide by jumping from one spot, extending their webbed feet, and gliding to the next spot. A Costa Rican flying frog can sail more than 50 feet in one trip! Show students pictures of flying frogs and other gliding animals, such as a Southern flying squirrel, a flying dragon, or a sugar glider. Point out the folds of skin that act like a parachute to help the animal ride the air. Now help students make flying frogs of their own. Each student will need a copy of page 28, a paper napkin, tape, a pencil-top eraser, and four 18-inch pieces of string. Have students follow these steps:
1 2
Color and cut out the frog on page 28.
3
Unfold a paper napkin and tape the frog cutout in the center.
Tie the string to each corner, as shown. Tie the four loose ends of the string together under the napkin and tape them to a pencil-top eraser. The eraser adds some weight to the parachute to make it descend properly.
could fly? In one picture, the frogs are watching TV . What TV programs do the students think frogs would like? Ask kids to guess why the frogs’ magic ends at sunrise.
4
Before launching the chute, drop an eraser from a height of a few feet so that kids can see how it falls without the aid of the parachute. Ask them what they think will happen when the eraser falls while attached to the chute.
5
Grasp the chute at its center and make sure the eraser is underneath it. Hold the chute up high and then drop it to see how the frog rides the air and glides downward. Explain that the parachute breaks the fall of the eraser by getting “caught” on the air and slowing it down.
Extend your look at flying frogs by exploring David Wiesner’s picture book Tuesday (Clarion Books, 1991). After sharing the book with the group, ask kids where they would go if they could fly on a lily pad. What do students think their dogs, cats, or other pets might do if they
19
The Lily Pad Press (Critical Thinking, Language Arts, Science)
Students read about frogs, learn about frog habitats, and play fun frog games. Make a copy of The Lily Pad Press on pages 29–31 for each student. Have students tape together the pages so that they can read it like a real newspaper. First, read aloud the news on the front page and lead a discussion on the issues involved. Next, use the classified ads in this activity on frog habitats. Explain to students that many frogs live near ponds, but frogs also live in tropical forests and in the desert. One small frog spends time in the water that collects inside the leaves of a bromeliad, a plant that grows in the tall trees of tropical forests. Introduce students to the term habitat and explain that a habitat is the place where a living thing finds what it needs to survive: food, water , shelter, and others of its kind. Acquaint students with various frog habitats by having them pretend to be a frog looking for a place to live. What better place to look than in the classified ads in The Lily Pad Press? Invite children to circle the ads that describe suitable frog habitats. When they’re done, go over their answers and explain that four of the six habitats are ideal for certain frog species.
ANSWERS: 1—Ponds are great for species like bullfrogs and leopard frogs. 2—Species such as the plains spadefoot toad and Australian water -
20
holding frog can live in desert habitats. 3—The bromeliad frog grows up in the water that collects in the leaves of the bromeliad plant, which grows in the branches of tall tropical trees. 4—Frogs do not live in places that are this cold year-round. 5—Red-eyed tree frogs and poison dart frogs would be right at home in this tropical habitat. 6—Frogs do not live in the ocean. Finally, have students play the games on the third page.
ANSWERS: Who’s Different? Frog 4 Cricket Crossing: 5 hops as shown.
Name _________________________________________________________ Date _____________________________________
What Makes a Frog a Frog? Draw lines connecting the words to the parts of the frog. Cross out words that are not parts of a frog.
long hind legs feathers large eyes
wings
wide mouth
antennae
long toes
eardrums on side of head nostrils on top of the head
scales
moist skin
21
Name _________________________________________________________ Date _____________________________________
All in the Family Circle the frogs. Draw a square around newts and salamanders. Draw a triangle around the caecilian (see-SIL-ee-un). Which animal is not an amphibian? Draw an “X” over it.
1
7
2
6
3
5
4
A frog is an ___ ___ ___ ___ ___ ___ ___ ___ ___.
22
Name _________________________________________________________ Date _____________________________________
Tadpole Transformation Color the pieces and cut them out.
When a tadpole changes into a frog, the process is called ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___.
23
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
e t a D
p m u J g n o L . : d s e p t m e c f i j t u e 6 o 1 p o f — y g r o r m e v f e d y e l r o f s o k n O c p o r l b a h s g e n n e o o a i c i m r n r l f a i N F F A _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5 4
5 4
5 4
0 4
0 4
0 4
5 3
5 3
5 3
0 3
0 3
0 3
5 2
5 2
5 2
0 2
0 2
0 2
5 1
5 1
5 1
0 1
5
0 1 t e e f 0 3 — n a m u h
5
t e e f 4 4 — o o r a g n a k y a r g
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
? t s e t 0 h 1 r a f e h t p m u 5 j n a c o h W
Name _________________________________________________________ Date _____________________________________
What’s in a Name? Match each frog name below with its picture.
1. Can you see through me? I got my name because parts of me are as clear as a windowpane. I am a _________________
2. I don’t say “quack,” but my snout looks like a feathered friend’s. I am a _________________
3. I may be red and plump, but you wouldn’t want me in your salad! _________________________. I am a _________________ _________________________.
_________________________.
4. Because I’m brown and have a pointy face, I look like a leaf on the ground. I am a _________________
5. When I get scared of enemies, I show off my fake “eyes” in back. They make me look too big to be eaten. _________________________. I am a _________________ _________________________. tomato frog glass frog false-eyed frog
6. I may look like a tasty fruit with my bright red skin and dark spots, but an animal would be unlucky to eat me! I am a _________________ _________________________.
strawberry poison dart frog duck-billed tree frog Asian leaf frog
25
Name _________________________________________________________ Date _____________________________________
Leap-Frog Pop-Up Card One Giant Leap High above the quiet pond, High above the trees, A frog went “hop” and didn’t stop, Not that I could see. He sailed along past planet Earth, And landed on the moon. The frog went “hop” and didn’t stop, Guess he won’t be back soon! If I could hop anywhere, I’d hop to _____________________________________________________.
26
Name _________________________________________________________ Date _____________________________________
Warning Colors Add and subtract to see which colors to make the frogs shown here. 3 + 4 = blue
9 – 4 = bright green
10 + 2 = orange
7 – 3 = red
5 + 2 + 1 = yellow
5 4
12
red and black striped frog
green poison dart frog
golden mantella
7
4
strawberry poison dart frog
blue poison dart frog
8 8 harlequin frog
corroboree frog
27
Name _________________________________________________________ Date _____________________________________
Amphibian Aviators Color this Costa Rican flying frog and cut it out.
28
Name _________________________________________________________ Date _____________________________________
T H E L I LY P AD P R ESS News Worth Croaking About Frog Mystery
Froggy Medicine Can you imagine a doctor telling you, “Take some frog juice and call me in the morning”? Scientists believe that frogs may help to cure human diseases. Some frogs make chemicals in their skin. These chemicals taste bad and are sometimes poisonous. Now scientists are studying these chemicals to see if they can be used for medicine. A frog in Australia makes a chemical that helps sores heal quickly. And a frog in South America makes a chemical that can be used as a painkiller. Scientists believe that there are lots of other medicines that can come from frogs.
Three years ago, a class of kids in Minnesota was on a field trip. They came upon a pond full of frogs. But these frogs were different from other frogs they had seen. Some had extra hind legs. Some didn’t have any legs at all. Some were missing eyes or even jaws. What had happened to these frogs? Thanks to these kids, scientists began studying this problem. They found ponds with deformed frogs in them in 12 different states! Scientists don’t know exactly what is causing frogs to be deformed. They think that a chemical used in farming could be polluting the frogs’ ponds. Scientists will keep studying the problem until the mystery is solved.
29
Name _________________________________________________________ Date _____________________________________
T H E L I LY P A D P R E S S
CLASSIFIEDS Circle the ads that describe places where frogs might live.
1. This Pond’s the Place!
4. Glacier Glory
Quiet, clean pond features sunny lily pads and lots of mosquitoes.
Snow-white ice stays frozen year-round. Pack warm clothes—the temperature doesn’t get above freezing here.
2. Like It Dry? Lovely desert with loose soil perfect for burrowing. Lots of spider and insect neighbors. A must-see when it rains!
5. Rain Forest Retreat Damp rain forest home with towering trees, warm weather, and more insects than you can count!
3. Penthouse Living Beautiful bromeliad plant with water-filled center high in a treetop. A perfect mini-pool!
30
6. Settle in the Sea Glorious ocean home with seaweed, coral, and fishy neighbors. All the saltwater you could want!
Name _________________________________________________________ Date _____________________________________
T H E L I L Y P AD P R E S S Who’s Different? Circle the frog that looks different from the others.
1
2
3
4
5
Cricket Crossing You are a cricket trying to get to the other side of the pond. But there are hungry frogs along the way! To get there, you must jump across on lily pads that
Safe!
don’t have frogs on them. You can’t skip over any pads or swim around them. What is the fewest number of hops that will get you across the pond?
Start on this side.
31
