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© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

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About Ready-Ed Publications Ready-Ed Publications was established in 1984 with the purpose of creating practical classroom blackline master activities. At the time, the role of the teacher was becoming ever more diverse with an increasing range of duties and responsibilities within the school and school community. Since then, the role of the teacher has continued to evolve with an escalating range of tasks and obligations, ensuring a reduction in time available to prepare work for the daily instructional program. Throughout these past 24 years, Ready-Ed Publications has built a reputation as publishers of Australian made, high quality, innovative, timesaving materials for teachers of primary and lower secondary levels. In addition, all materials are based on state or national curriculum guidelines or specific age-related interest areas and subjects.

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Ready-Ed Publications aims to assist busy professionals by making available contemporary classroom materials that contain relevant and stimulating work to support the requirements of the curriculum.

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Acknowledgements: i.

Front cover photograph of a Western Australian spotted-thighed frog (Litoria cyclorhyncha).

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Frogs © 2008 Ready-Ed Publications Printed in Australia Author: Sally Murphy Illustrator: Melinda Brezmen Typesetting and Cover Design: Shay Howard

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y•

Photographer: Gary Geoffrey Sutton.

ii. Clip art images have been obtained from Microsoft Design Gallery Live and are used under the terms of the End User License Agreement for Microsoft Word 2000. Please refer to www.microsoft.com/permission. iii. iStockphotos.com

iv. Corel Corporation collection, 1600 Carling Ave., Ottawa, Ontario, Canada K1Z 8R7.

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v. Photos from individual sources have been acknowledged where applicable. While every attempt has been made to acknowledge the ownership of photos used herein, in some instances this has not been possible. If you know of the photographers for these images, please contact the publisher so that proper acknowledgement can be given.

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Published by: Ready-Ed Publications PO Box 276 Greenwood WA 6024 www.readyed.com.au info@readyed.com.au

ISBN: 978 1 86397 749 4 COPYRIGHT NOTICE All rights reserved. The reproduction of any part of this book for an entire school or school system or for commercial use is strictly prohibited. No form of this work may be reproduced, transmitted or recorded without written permission from the publisher. Requests for such permissions should be addressed to Ready-Ed Publications.

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What Is a Frog?............................................. Page 4 Frogs and Toads ............................................ Page 6

Frog Homes .................................................. Page 9

A Frog’s Life Story ....................................... Page 14

© ReadyEdPubl i cat i ons Frog Anatomy ............................................. Page 18 •f orr evi ew pur posesonl y• Mealtime .................................................... Page 22

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Frogs From Around the World ...................... Page 24 Predators and Defence ................................ Page 30

. te Frogs into Backyard Ponds ....... Pageo Encouraging 38 c . c e r Froggy Petsh ................................................. Page 39 er o t s super Under Threat .............................................. Page 34

Frog Stories................................................. Page 41

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What is a Frog?

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The frog is a member of the group of animals known as amphibians. Amphibians begin their lives in the water. They have tails to swim and gills to breathe. They then develop into adults which live on land and use lungs to breathe air. Frogs start life as tadpoles and then develop into adult frogs.

red-eyed tree frog. © ReadyEdAP ubl i ca t i ons •f orr evi ew pu pos es o nl y • Asr adults, frogs still need plenty

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This tadpole has just started the transformation process. Tiny legs are visible below the tail.

of water to survive. Their skin needs to stay moist, because as well as breathing through their lungs they also breathe through their skin. As a result, most frogs live close to water – in ponds, swamps, or creeks. It also means that many frogs are nocturnal. They are more active at night when the sun cannot dry out their skin.

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© iStockphoto.com/Thomas Mounsey

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Frogs can be as small as one centimetre long and as long as thirty centimetres. They have big back legs for hopping and jumping, and smaller front legs. 4


Fear of frogs is called r o e t s Bo ranidaphobia. r e p ois u Fear of toadsk S bufonophobia.

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Did you know?

Fear of all amphibians is batrachophobia.

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Frog species which swim a lot have webbed toes, to make swimming easier. Frogs can be very noisy. Their loud croaks can make them sound much bigger than they are. They croak to attract other frogs. This is called a mating call.

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© ReadyEdPubl i cat i ons This• frog is r a fully grown f o r e vi eadult. w pur posesonl y•

o c . che e r o t r s su er There are over 5000 species of p frog. They can be found in most countries of the world – in both warm and cold climates, living in deserts and swamps and even in trees. Some people even keep frogs as pets.

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Frogs and Toads

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Frogs and toads are closely related and, at first glance, it is hard to tell whether an animal is a frog or a toad. Both are amphibians, but frogs belong to the animal family Ranidae and toads belong to the family Bufonidae.

© iStockphoto.com/Sascha Burkard

Appearance

Although frogs and toads both have four legs and a similar body shape, frogs usually have a narrower body, with a more defined waistline. Toads have a shorter body, which is flatter and wider.

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This American toad (Bufo americanus) has rough, bumpy skin.

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o c . che Frog skin tendsr e to be smoother o t r sbecause they stay and moist, sup r e damp. Toads have bumpy or © iStockphoto.com/Eric Isselée

This poison dart frog (Dendrobates auratus) has smooth, moist skin.

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Frogs’ back legs are usually longer, making them better hoppers than toads, and their feet are usually webbed for swimming. Toads have shorter, more muscular hind legs, and can walk.

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warty skin and are dry to touch, because they are often found further from water. So, if you touch a frog, it will feel slimy or velvety, while a toad will feel a little rough.


while toads lay eggs in long chains or strings. Some toads (nectophrynoides) don’t lay eggs at all – they bear live young.

r o e t s While these differences can help B r e ooan animal is a to decide whether p u frog or a toad, it k is sometimes still S hard to decide. Some frogs, for

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A frog’s eyes are often bulgy, standing out from the head. A toad’s eyes are usually set into the head. Behind a toad’s eyes are sacs (the parotoid glands) containing poison, which they release when threatened – for example, if bitten by a predator. Frogs don’t have these poison sacs, although some frogs do have poisonous skin.

example, have bumpy skin, and some toads will be found near water. © iStockphoto.com/Tree4Two

Habitat

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Frogs can be found on every continent except Antarctica. Toads are also found in most parts of the world, but are not native to Australia, New Zealand, some parts of Africa and Antarctica. Some toads have been introduced into these parts of the world.

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Another way of telling a frog from a toad is by where it is found. Generally, frogs spend their lives in or near water or moist surroundings. Toads need water or moisture to reproduce, but often live away from water.

Frog eggs clump together at the edge of the water.

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When they reproduce, frogs lay their eggs in clusters or clumps,

© iStockphoto.com/Tina Lorien

Toad eggs in strings.

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© iStockphoto.com/Eric Delmar

© ReadyEdPubl i cat i ons poisonous to bigger animals The Cane Toad •f orr evi ew pu r posesonl y• which try to eat them. They also

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breed prolifically and so compete with native animals for space, food and shelter.

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The cane toad (Bufo marinus) was deliberately introduced into Queensland, Australia in 1935. Scientists hoped that the toad would control beetles which were a pest to sugar cane crops. Instead of getting rid of the pest, cane toads became pests themselves.

One of Australia’s biggest pests, there is no known way to control or eradicate the cane toad effectively.

o c . che e r o t r syou know? uper Did Since 1935 cane toads have s spread throughout northern Australia, almost to Western Australia and down into New South Wales. They are a threat to native species because they eat smaller animals and are 8

A group of frogs is my called an ar army my. A group of toads is called a knot knot.


Frog Homes

r o e t s Bo r e p ok u S Near Water

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Frogs are found on every continent except for Antarctica, where it is too cold for the animals to survive. Although all frogs need water to survive, they are found in a wide variety of habitats. Frogs can be found in trees, in deserts, high in mountain ranges and even sheltering in caves. Each frog family must adapt to its environment.

Where there is a permanent water source such as a pond, stream or river, frogs will be found living close by. They will shelter under logs, or in long grass or reeds. They will generally be found near stiller water, and in places where the water is shallow enough for them to climb out.

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places to breed. Sometimes they don’t have all these things in one place and so must move, or be patient in finding what they need. For example, they may not have a place to breed all year round, so will wait until the conditions are right to do so.

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© ReadyEdPubl i cat i ons Apart from needing water, all •need f oshelter, rr ev i e w pur posesonl y• frogs food and

Other frogs live where there is regular water. They might find a drain or even a garden soakwell which fills regularly, and stays moist for a long time after it drains. If the water dries up the frog will move on until it finds a new water source, or it might bury itself in the mud at the bottom of the puddle until the next time it rains.

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© iStockphoto.com/Morley Read

Tree Frogs

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© iStockphoto.com/Mark Kolbe

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The name ‘tree frog’ is a little misleading, because not all tree frogs live in trees. Tree frogs have round sticky discs on the ends of their toes which make it easy for them to climb trees and other plants, but also anything else they might like to climb.

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The sticky pads on the feet of this White’s tree frog help it to cling to the reeds.

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This Amazon leaf frog (Cruziohyla craspedopus) climbs a vine in the Ecuadorian Amazon Rainforest.

Many species of tree frogs live in rainforests and jungles, but they also live in and around homes. In tropical areas it is common to find tree frogs living in people’s houses – and they are often found in toilet bowls and cisterns. Tree frogs can also be found on the ground and rocks, especially close to water.


© iStockphoto.com/Kevin Kaminski

Desert Dwellers

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Frogs such as the water-holding frog (Cyclorana platycephala) and the spadefoot toad dig deep into the desert sands to escape the heat, digging their way out again when it rains. They will then mate, laying their eggs in puddles, and hunt for food. The young tadpoles develop quickly, so that when the earth dries out again they, too, can dig down into the sand.

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Although frogs need water to survive, some species have adapted to life in the desert. They become inactive during hot, dry periods, and use rainy times to hunt and to reproduce.

This desert toad has skin which helps to camouflage it against the rocky terrain.

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© iStockphoto.com/Kevin Ross

© iStockphoto.com

o c . che e r o t r Did you know? s super In tropical areas it is

The spadefoot toad has a spadelike growth on its rear legs which allows it to dig up to a metre beneath the ground.

common to find tree frogs living in people’s houses – and they are often found in toilet bowls and cisterns.

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the ground is not as cold, as frosts are usually limited to the surface soil.

Other frogs dive deep below the r o e t s Bo r water of lakes and ponds and e p hibernate below o the water. Even u k when a lake freezes, the water at S the bottom does not. Frogs such

Cold Frogs

Some frogs dig not to escape the heat, but to escape the cold. In places where it snows or gets very cold in winter, these frogs hibernate by digging. They dig beneath the ground, or move into the abandoned burrows of other animals, to escape winter forests. The temperature below

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© iStockphoto.com/Kevin Snair

as the leopard frog sit in the mud at the bottom of the lake, absorbing oxygen through their skins to breathe. In the spring when the water temperature rises they swim to the surface to hunt and reproduce.

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o c . che e r Did you know? o t r s supe r The leopard frog survives

freezing winter temperatures by hibernating at the bottom of a lake until the water warms up in spring.

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Water-holding Frog

© iStockphoto.com/Johann Piber

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When the weather is hot and dry, the water-holding frog digs deep into the sandy soil. It slows down its metabolic rate and then secretes a special mucous membrane which forms a balloon around the frog. This balloon stores water to keep the frog moist and hydrated. Nose holes are left free to enable the animal to breathe slowly.

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The water-holding frog lives in arid and semi-arid areas of Australia. About six centimetres long, this frog survives in the desert by using a process called aestivation.

This frog takes shelter in a cave.

Did you know?

The cave-dwelling frog might be found sheltering

© ReadyEdPuinbal i cat i ons cave, but does not itss whole life there. •f orr evi ew pur pspend ose on l y •

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during the day or during very hot, dry periods. At

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When it rains in the desert, the frog will emerge from this cocoon and dig its way to the surface to resume normal life.

Rather, it shelters in caves and rock crevices

night, and during wet periods, it leaves the cave

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to hunt and to breed.

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A Frog’s Life Story

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© iStockphoto.com/Jolande Gerritsen

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In Brief: The Frog Life Cycle

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A frog starts its life as one of hundreds of eggs laid by its mother By about twelve weeks the tadpole and fertilised by its father. The eggs has become a froglet, with a froglike body and legs, but a still form a clump in still water. visible tail. The frog has About three weeks after the eggs developed lungs and the gills are are laid, the tadpole emerges. It sealing up. breathes through gills and swims using a tail. The tadpole feeds on Soon, the tail disappears completely, and the tadpole has algae in the water. now become a frog. The adult After six weeks as a tadpole, tiny frog will soon look for a mate to back legs begin to grow. The begin the life cycle all over again tadpole’s body gets longer and with a fresh clutch of eggs. then the front legs start to emerge.

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Mating Calls

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When you hear a frog croaking on a damp evening, the chances are it is looking for a mate. Each frog species has a distinct call and the female frog will respond to the male’s calls when she is ready to mate. The frog croaks by forcing air into special pouches called vocal sacs. The air travels from the frog’s lungs, over its vocal chords and into the vocal sacs, which amplify the sound. Females hear the croaking and respond by looking for the male.

© iStockphoto.com/Peter Herbig

The male frog holds the female as she lays her eggs.

they are laid the male fertilises them. The frog will lay hundreds or even thousands of eggs, because many will not hatch. Even if they do hatch, many tadpoles will not survive to adulthood.

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o c . che e r o Whent the eggs have been r s supelaid r and fertilised they form This frog calls for a mate. Mating When the male frog sees the female, he ‘hugs’ her by clasping her around the back. The female frog then lays her eggs, and as

a clump in the water. Some frogs will leave the eggs unattended, while others wait until the eggs hatch to care for their young.

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© iStockphoto.com/Achim Prill

These tadpoles swim in shallow water, amongst leaves and other natural debris.

© ReadyEdPubl i cat i ons Tadpoles •f orr evi ew pu r p os enoticeable sonl y • frog. The first change

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is the gradual appearance of tiny back legs, just above the base of the tail. After this the head and body start to become more obvious, with a longer body and a more obvious head.

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When the eggs hatch, the tadpoles which emerge do not look much like their frog parents. They have a round body and long tail, and breathe through gills. The tadpoles must live completely in water, like fish, until they develop legs and lungs.

o c . che e r o The tadpoles eat algae, and also t r s s r u e p small insects and anything else they can find in the water. Many species will actually eat other dead tadpoles or eggs. Soon, the tadpole will begin the process of transformation into a 16

Did you know?

Another name for a tadpole is a pollywog.


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© iStockphoto.com/Lee Pettet

Froglets

Depending on the species, by about twelve weeks the froglet develops front legs, and the frog’s lungs have developed enough for the young frog to breathe out of the water. The tail has become short and stumpy and soon it will disappear altogether.

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These tadpoles are just beginning to sprout tiny back legs. Soon they will be frogs.

This adult spotted tree frog will soon begin the life cycle over again by seeking a mate and producing a new generation of tadpoles.

Adult Frogs

Between twelve and sixteen weeks © ReadyEdP ubl i cat i ons after the tadpole has hatched, the frog reaches adulthood. In• areas •f orr evi ew pur p o s e s o n l y where water is scarce – such as

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the desert – the life cycle is shorter which is an adaptation to the short wet season. The adult frog will live from between one and forty years, depending on the species, but the average is about four years. Frogs kept in captivity as pets usually live longer than those in the wild.

o c . che e r o t r s supe r Adult frogs will seek out partners

This bullfrog tadpole has both front and back legs visible. Soon his tail will disappear and he will be able to leave the water.

to mate and breed with when conditions are right. For many species this is in spring or autumn, but in harsh conditions frogs will wait until there is plenty of moisture. Other frogs may breed all year round. 17


Frog Anatomy

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Legs and Feet Frogs have four legs – though their front legs are also sometimes called arms. These front legs have feet with four toes, whilst the rear legs have five toes each. The rear feet have webbed toes to help the frog to swim.

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Like any animal, a frog needs to be able to see and hear, to eat and digest, and to move around. Some of its functions are specially adapted to life in and around water. Others help it to camouflage, or to move quickly to escape predators.

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Frogs’ hind legs are long and muscular to help them to hop. Many frogs are able to hop twenty times their body length. For a human child that would be a jump of around twenty five metres.

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This frog’s webbed toes and muscular legs help it to swim and to hop long distances.

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This red-eyed tree frog has long back legs to help him to hop, and sticky pads on his toes to help him to grip.

Frogs which climb, such as the many varieties of tree frog, have sticky pads on their toes to help them to grip.


Eyes, Nose and Ears

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As the eyes are at the top of the head, a frog can sit in the water with just its eyes and nose above the waterline.

© iStockphoto.com/Marcus Jones

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Frogs’ eyes come in many different colours and shapes, but what they have in common is the way their eyes bulge out from the head. Because the eyes stick out like this the frog can see to the front and the sides, as well as some of what is behind it. Their range of vision is 180 degrees.

The frog’s eyes have another interesting function. When the frog swallows food, its eyes sink into the roof of its mouth, helping to push the food down into the stomach. From the outside, it looks as if the frog closes its eyes every time it swallows. When this happens the frog’s bottom eyelid slides up over the eye.

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The frog’s nose is very simple. Two small holes – the nostrils – are visible on the top of its face, below the eyes. These nostrils have valves which open and close to allow air in and keep water out.

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o c . che e r o t r s supe r The frog’s ears are also simple.

This frog’s bulging eyes help it to see in all directions. Behind the eye the frog’s ear can be seen as a circle of similar size to the eye. In front, the nostril is visible on the frog’s nose.

A round membrane – the eardrum – sits on the skin behind the eyes. The membrane detects sound and the ear canal below this helps the frog to keep its balance. 19


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The strawberry poison dart frog (also known as the blue jeans dart frog) signals danger with its bright colours. The skin of this frog is poisonous to predators.

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Although frogs are most commonly green or brown, some frogs have bright skin colours. The green and brown frogs blend in easily to their environments. Other colours – including blues, reds, yellows – might make camouflage harder, but can be useful in attracting a mate, or in signalling danger to potential predators.

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A frog’s skin doesn’t just provide a cover. It is an integral part of its bodily regulation. Frogs use their skin to breathe and to absorb water. A frog does not drink water. Instead, it absorbs water through its skin.

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Skin

o c . che e r o t r s sup Although a frog does have lungs, er it can only use these when it is out of the water. When in the water, the frog absorbs oxygen though the skin. Even out of the water, the oxygen absorbed in this way helps it to survive.


Inside the Body Inside the frog’s body are organs which function similarly to those of humans. The frog has a brain and nerves which help the body to function and respond to its surroundings. There are also simple lungs for breathing, a heart and veins for pumping blood around the body, and digestive and excretory systems for processing food and removing waste.

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© iStockphoto.com/Glenn Bartley

© ReadyEdPubl i cat i ons f osmooth, rr ev i ew ur posesonl y• This• frog’s moist skin p

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It is because the frog absorbs oxygen through its skin that it must keep its skin moist. If the skin dries out, the frog will suffocate.

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helps it to drink and to breathe.

o c . che e r o t r s super Did you know?

Like humans, frogs have a skeleton of bones including a skull, leg and arm bones, and a spine.

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Mealtime

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The frog’s mouth holds small teeth and a long, sticky tongue. The teeth are not usually used for chewing, but for holding onto prey. Most frogs can catch prey using their tongues. Inside the mouth, the tongue is folded or rolled backwards. When it sees an insect, the frog can rapidly flick out its tongue. Because the tongue is sticky, the insect sticks to it and is drawn back into the frog’s mouth.

Did you know?

Unlike most animals, a frog’s tongue is attached at the front of its mouth instead of the back.

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© iStockphoto.com/Craig Boggan

o c . che e r o t r s super This green tree frog prepares to catch a cricket. When the insect is close enough, the frog will flick out its tongue and trap the cricket.

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© iStockphoto.com/Philip Puleo

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This frog has just caught itself some dinner. An insect is seen hanging from its mouth.

© ReadyEdPubl i cat i ons Frogs carnivorous –e that •are f o rr evi wis pur p os es onl y• Did you know?

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Frog legs are considered a delicacy in France, where they are usually fried and served with a buttery garlic sauce. Frog legs are also eaten in other countries including China and parts of Greece.

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they eat other animals rather than plants. Depending on the size and breed of the frog, it will eat flying insects, beetles, worms, snails, spiders and small fish. Bigger frogs will often eat smaller frogs, and some will even eat small mammals such as mice.

o c . c e hebyrthe r When food is swallowed o t s su frog it travels into the stomach and per on to the small intestine, where most of the digestion process happens. Just as with humans, food and fluid that are not needed by the body pass through the body in the form of faeces and urine.

© iStockphoto.com/Pawel Strykowski

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Poison dart frogs are so called because their skin is poisonous to touch, and harmful to predators. The bright colours act as a warning to potential predators, and the speckles of the skin also help the frog to blend into surroundings when the animal is still.

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Frogs From Around the World

Poison dart frogs are very small – between one and six centimetres long. It was once thought that the poison from poison dart frogs was used by South American tribesmen to manufacture poison arrows and darts, but it is now known that only two or three species of these frogs are actually toxic enough for this use.

© iStockphoto.com/Brandon Alms

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shapes and sizes, and while all frogs are fascinating to watch, some are a little more unusual than others.

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© ReadyEdPubl i cat i ons f o r e vi ew pur posesonl y• Frogs • come inr many different

. te o c The most brightly coloured frog . c e her r family is that of the poison dart o t s uper frog, also sometimes called s Poison Dart Frogs

poison arrow frogs. These frogs (from the family Dendrobates) come in many colours including yellows, blues, reds and blacks and are found in rainforests in Central and South America. 24

© iStockphoto.com/Eric Isselée

This yellow and black poison dart frog (Dendrobates leucomelas) is found in Brazil and Guyana.


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These blue dart frogs (Dendrobates azureus) are found in Suriname in South America.

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When poison arrow frogs are kept in captivity (such as in zoos), their skin loses its toxicity. This is because the poison is created during their digestive process when they eat specific types of insects found in the rainforest. In captivity, their diet does not produce these toxins.

© iStockphoto.com/Steve Geer

© iStockphoto.com/Mark Kostich

The Peacock Tree Frog

Although its name suggests bright colours, the peacock tree frog (Leptopelis vermiculatus) is actually fairly plainly coloured, compared to some of its frog cousins. Its brown skin tones are not the source of its name. Instead, it was given the name ‘peacock’ because of its unique call, or croak, which sounds like the call of a peacock.

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o c . che e r o t r s s per This black and white dart frogu

The peacock tree frog is found in the rainforests of Tanzania. © iStockphoto.com/Brandon Alms

(Dendrobates tinctorius) is one of the bigger members of the species, growing up to six centimetres long.

A peacock tree frog. 25


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The fire-bellied toad (Bombina orientalis) has a green speckled back and fiery red underside.

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y• The Fire-Bellied Toad

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The fire-bellied toad manufactures the bright red colour by eating aquatic organisms which are rich in carotene (an orange pigment).

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The fire-bellied toad is found in Korea and parts of China and Russia. 26

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Another frog which uses its colour to scare off predators is the fire-bellied toad (Bombina orientalis). Whilst this frog has a green or brown back which allows it to blend into its surroundings, it has a bright red or orange stomach. When it is threatened by a predator, the toad shows this underside, which startles predators and gives the animal a chance to escape.


The Motorbike Frog

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Another frog which gets its name from the sound it makes is the motorbike frog (Litoria moorei). This frog, commonly found in the southwest of Western Australia, has an unusual croak. First it makes a series of rising tones which sound like a motorbike revving. This is followed by a warbling growl. Together, the calls sound like an approaching motorbike. This distinct croak can be heard from more than a hundred metres away.

Gastric Brooding Frog

Like many other frogs, the gastric brooding frog (Rheobatrachus vitellinus) gets its name from something it does. But it isn’t its colour or its call which gives this frog its name. Instead, the gastric brooding frog is so called because it grows its tadpoles inside its stomach.

The motorbike frog is often found in suburban gardens – a noisy addition to a backyard.

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Because this frog is endangered, little is known about it, but it is believed that the frog lays its eggs, and then swallows them. The tadpoles hatch and develop inside the mother’s stomach, which expands as the tadpoles grow. When the tadpoles have developed into young frogs, the mother regurgitates them and they leave via her mouth.

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A motorbike frog clings to a reed. 27


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Flying Frog

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The flying frog cannot really fly, but it has developed large membranous webs between its toes. When hunting, or when being hunted, the frog can jump big distances between trees and branches, spreading its webbed toes to glide up to fifteen metres.

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The flying frog also exhibits some strange behaviour which gives it its name. Also known as the parachute frog, the Wallace’s flying tree frog (Rhacophorus nigropalmatus) spends most of its life living in trees in Malaysia and Borneo.

Tree Frog © ReadyEdWaxy Pub l i cat i ons The waxy tree frog •f orr evi ew pu r poses onl y• (Phyllomedusa sauvagii) gets its

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Secret Weapon: This Wallace’s flying tree frog keeps its webbed toes a well-hidden secret.

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name from the waxy feel of its skin. This frog lives high in the rainforest canopy, where temperatures are higher and humidity is lower. To avoid drying out, the frog produces a waxy substance which it uses to coat its skin. The wax traps moisture close to the skin, keeping the frog moist.

Ornate Horned Frog The ornate horned frog (Ceratophrys ornata) is an impressive-looking frog found in South America.


Surinam Toad The Surinam toad has strange reproductive habits. The mother carries the fertilised eggs in a pouch of membrane on her back. The eggs hatch and the tadpoles develop in the pouch, eventually merging as toads.

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The ornate horned frog is large and fairly inactive. It lies in wait for its prey, but when threatened or attacked it will jump about. Its croak is a loud bellow a little like that of a cow. The ornate horned frog is also sometimes called the Pacman frog because it looks like the round video game character, Pacman.

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Its name comes from a large flap of skin, which looks like a horn and protrudes above each eye. The horn is actually soft and not dangerous, but the frog itself is carnivorous, with a big mouth which it uses to bite and attack its prey. It will eat other frogs, lizards and mice.

Did you know?

The world’s biggest frog is the goliath frog (Conraua goliath) from Africa. It grows to around thirty centimetres in length.

© ReadyEdPubl i cat i ons The smallest frog is the gold •f orr evi ew pur p o(Psyllophryne sesondidactyla) l y• frog

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which is less than a centimetre in length.

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This ornate horned frog lies in wait for a meal, which it will trap with its huge mouth.

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Predators and Defence Enemies

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Frogs hunt other animals (and insects) for food in order to survive. In the same way, other, bigger animals also hunt frogs for their own food. On land, frogs can be eaten by birds, snakes, lizards and animals such as foxes and cats. In the water, frogs can be eaten by fish, diving birds and water mammals. Little frogs can also be eaten by bigger frogs.

frog has, © ReadyEdThis Pu bl i cunfortunately, at i ons become dinner for a copperhead snake. •f orr evi ew pu r posesonl y•

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o c . che e r o t r s s r u e p With so many things out to eat them, frogs have had to come up with ways to avoid ending up as another animal’s dinner.

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Even when swimming in the water frogs are still vulnerable. This grey heron has caught itself a frog for dinner.


Appearance Other frogs, rather than blending in, choose to stand out from the foliage with bright skin colours. The bright colours of poison dart frogs warn potential predators that the frog is poisonous. Other frogs have bright bellies which they flash when confronted by a predator. The bright colour warns the predator to stay away, or may momentarily startle the predator, giving the frog time to escape.

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Some frogs avoid being eaten by using camouflage to hide from potential predators. Many frogs have green or brown skin tones which blend well with water and plants. Stripes and speckles also help frogs to blend into their surroundings. When a frog is threatened, it may close its eyes and stay very still, to avoid being seen by the predator.

© ReadyEdPubl i cat i ons Some frogs try to look bigger to •f orr evi ew pur posesonl y• scare predators away. When

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startled, the frogs will inflate themselves so that they look too big for the predator to catch. Other frogs have false ‘eyes’. The false-eyed frog (Physalaemus nattereri) has two markings on its lower back which look like large eyes. When under threat, the frog will turn its back to the predator, showing ‘eyes’ which look like they belong to a bigger animal.

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This grey tree frog blends well with the bark of a tree whilst the green tree frog blends in with the leaf on which it rests.

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© Robert Puschendorf

Jumping and Climbing

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Poison

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If they can’t scare potential predators away, most frogs have another useful way to escape being eaten – their strong hopping legs. Their muscular legs can take them a long way in a single hop, and their range of This frog doesn’t need to vision means they see predators camouflage. Its bright colours warn coming even when they predators of its poisonous skin. approach from behind. Some frogs will dive deep into the water as they jump, helping them to escape land-dwelling predators, while others will jump or climb into trees.

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Toads have poison in special glands behind their eyes. This poison is pushed out when the toad is threatened. If it hits the predator in the eye, or squirts in its mouth, it can cause burning and stinging, again scaring the predator away. In some cases this poison will make the predator ill. 32

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As well as having bright colours, poisonous frogs and toads use their poison to get rid of predators. The poison secreted from poisonous frogs’ skin tastes awful, and will cause the predator to spit out the frog and to avoid similar-looking frogs in the future.

At the first sign of trouble, this bullfrog (Rana catesbeiana) will use its strong rear legs to jump free.


Disease

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Even if they escape all their predators, frogs face another peril within their natural habitats – disease. Just like humans, frogs are susceptible to illness and some diseases can cause death in individual frogs or whole populations. In recent years, amphibians around the world have been affected by chytridiomycosis. This disease is caused by the chytrid fungus (Batrachochytrium dendrobatidis), a fungus which lives in water and soil, and can invade the frog’s skin. The fungus is present in Australia, New Zealand, America and Europe, and is believed to have caused or hastened the extinction of some frog species. Scientists have not yet determined why the disease is spreading, or how to cure it.

declining, including the disappearance of at least ten frog species in Australia, and it is widely accepted that this is because of the destruction of their natural homes.

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While frogs are naturally hunted by other native predators, in Australia it is introduced species which threaten frog populations. Animals such as the European fox, the domestic cat and the cane toad hunt native frogs and compete for habitat. Frog species such as the golden bell frog have become endangered or extinct due to hunting from introduced species.

o c . che e r o t r s super Under Threat As well as facing threats within their natural habitats, frogs suffer because of the destruction of these habitats. Worldwide populations of frogs are

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Under Threat Pollution

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Pollution is one factor which affects and destroys natural habitats. When chemicals and rubbish enter waterways, they pollute the water in which frogs swim, eat and breathe. Frogs absorb water through their skin, at the same time absorbing anything else that is in the water. If their food comes from within the polluted water, or from polluted air, again the frogs absorb some of the pollutants. Frogs are also prone to being caught or trapped in litter which lies or floats around their homes.

UV rays are impacting on many frog species.

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Pollution in this pond will affect any frogs living there.

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Scientists also believe that depletion of the ozone layer is impacting on frog species. The ozone layer is part of the earth’s atmosphere which helps to filter harmful ultraviolet (UV) rays from the sun. As the ozone layer is depleted by pollution and natural changes, more UV rays reach the earth’s surface. It is believed that this harms frogs’ skin and also affects the development of their eggs.

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Ozone Layer


Clearing of Habitats

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In some instances frogs’ habitats are deliberately cleared by human activities. Forest areas are logged for timber and land is cleared to make way for building or mining projects. Swamps and wetlands are drained so that the land can be used for other purposes. When this happens, frog populations may be wiped out or be forced to find new homes.

He may look cute, but this cat can be bad news for native frogs.

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As previously discussed, frogs’ habitats are also affected by introduced animal species. Fish which have been brought into the country for sport fishing compete with frogs and also damage the local plant life and ecology. Pets such as cats, and feral animals such as foxes and cane toads, all damage the delicate environment on which frog survival depends.

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The wide scale clearing of trees like this can destroy the habitat of any frog species living in the area.

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What Can Be Done? Save Our Frogs

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Projects which aim to clean up waterways and stop pollution can be a big help to frogs. Removing rubbish and working to ensure that water is clear and free of chemicals, pesticides and

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Although habitats are under threat, there are things that can be done to protect the habitats and the frogs that live in them. In Australia and around the world small and large projects aim to look after frogs and their homes.

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o c possible, clearing of . che Wherever e r natural vegetation should be o t r s sup eror minimised. Not only stopped

This unpolluted creek in the Australian rainforest provides a clean environment for native frogs.

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On farmland, keeping farm animals away from river and creek banks can also help. Animals with hooves flatten the earth around waterways and destroy plant life. Frogs need the plants for shelter and food.

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other toxins can make it possible for frogs to breed and live in and around waterways.

do frogs need their native plants, but their removal can also encourage weeds and introduced plants to thrive, causing further problems for frogs.


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Frogs need clean air, native vegetation and unpolluted waterways to survive.

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Reducing air pollution can also help, by minimising ozone damage and providing clean fresh air for frogs, plants and the insects on which they feed.

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Japanese koi make appealing pets in ponds, but if released into waterways can damage frogs and their environments.

o c . c e he r Domestic pets should not be o t r s uper allowed to wander free. Pets fish and frogs should never be released into waterways. Even though we want frogs to thrive, releasing a frog which is not native to an area may cause problems for the native frogs.

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Encouraging Frogs into Backyard Ponds

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One way of aiding the survival of native frog species is to encourage them to live in backyard ponds. However, only frogs native to a local area should be invited to take up residence – pet exotic frogs should never be released outside. Native frogs should not be captured for backyard ponds. Instead, build the pond and provide the right environment and the chances are that frogs will take up residence.

there should be plenty of rocks, leaf litter and native plants around the edges. Frogs will look for shelter as well as water.

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The bottom (or base) of the pond should be covered in washed sand or gravel, and 38

Before you build a pond you should check with your local authorities as in some places there are restrictions or guidelines in place regarding building ponds. Before you dig you should also check what is beneath the ground – you don’t want to dig into a pipe or wires. Once your pond is built it may take a while for local frogs to discover it, depending on where the nearest frog colony is and the time of year you build the pond.

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Backyard ponds should be located in a place that provides both sun and shade. Because frogs can be noisy, it should not be close to your house, or your neighbour’s. The pond should be shallow around the edges so that frogs can climb in and out, but at least half a metre deep in one or more places so they can dive. Because of this depth, ponds should not be located in places where young children play.

a pump will keep the water moving and keep it clean.


Froggy Pets

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To set up a home for your frog you will need a glass tank – an aquarium or vivarium. The size you will need will depend on the breed of frog you are going to keep. Your aquarium will need a light, heater and a net cover. Because frogs don’t spend all their time in water, you’ll need to

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Frogs can make interesting pets and don’t require as much space as bigger animals. In most places, however, it is illegal to simply catch a frog and keep it in your house. You will need to visit a pet store or licensed frog breeder to purchase your frog and find out what special equipment you will need.

Frogs can make interesting pets.

© ReadyEdPubl i cat i ons provide both water and sand •f orr evi ew pur pos es on l y •or

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rocks, as well as some plants. Again, you’ll need to find out what specific plants and soil your frog breed needs. You should set up the aquarium well before you bring your frog home. This will give you a chance to work out the heating and also to test the water and make sure it is balanced for your frog. Set your aquarium up on a flat, steady surface away from direct light. So your frog can’t escape, you will need a lid, but because your frog needs air, a screened lid is preferable.

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r o e t s Bo r e p ok u S Once you bring your frog home,

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When you buy your frog, find out what kind of food it needs. Often this will be crickets or insect larvae. Many frogs require their food to be still alive when they are fed, so that they ‘catch’ it for themselves. it is best to avoid handling it too often. If you do need to pick it up, wash your hands with clean water (no cleansers) first. Then, cup the frog gently or pick it up near the shoulder area. Avoid the frog’s stomach, which is very sensitive. Again, you should ask your frog retailer to show you how to do this when you buy the frog.

handling your pet frog.

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Enjoy your frog pet and remember not to let him go outside.

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Did you know?

A frog’s stomach is very sensitive. If you do need to handle your frog, make sure you do it gently.

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fertility and also used frogs in art and literature. Aristophanes wrote a play called The Frogs which featured a chorus of frogs, and Aesop wrote several fables featuring frogs.

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Froggy Stories

Other ancient cultures also featured frogs in their folklore. The ancient Chinese associated the frog with wealth and good fortune, while the Australian Aborigines and American Indians saw the frog as the bringer of rain. In India the sound of thunder was said to be made by a frog in the sky.

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In ancient Egypt, the annual flooding of the Nile was followed by the appearance of thousands of frogs, and so the frog became associated with fertility. The Egyptian Goddess of Fertility, Heqet (also called Heket) was shown as a frog or as a woman with a frog’s head. Four of the male gods associated with creation were also frog-headed.

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Frogs are popular characters in modern books, songs and films, but they have also been part of myths and legends since ancient times.

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The ancient Greeks and Romans also saw the frog as a symbol of

If you kiss a frog it may turn into a prince!

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Children are taught to count by singing frog songs such as Five Speckled Frogs, and watch Kermit the Frog on Sesame Street, as well as a never-ending supply of picture books featuring froggy characters. Adults, too, like frogs. They collect frog ornaments, wear frog clothes and hang frog art in their homes.

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Frogs and toads have continued to appear in stories and fables. The claim that if you ‘kiss a frog it will turn into a prince’ comes from the story of the Frog Prince, a story made popular by the Brothers Grimm. The version you can read on the next page has a happy ending and is gentle and tender, but the original story was not so nice, with the Princess hurling the frog against a wall before he transformed.

Perhaps frogs are so popular because they are so widespread – frogs live in most places on earth. Or perhaps it is because their cute appearance makes them appealing to people. Whatever the reason, frogs continue to be a source of fascination around the world.

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The frog appears in many other fairy tales and stories from around the world, including Asia, Europe, Africa and America. In Australia, Aboriginal legend tells the tale of Tiddalik, a frog who is so thirsty he drinks all the water in the land. The other animals beg him to release the water, but he refuses until they manage to make him laugh. It is thought that this story was inspired by the water-holding frog (Cyclorana platycephala).

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Frog Stories 1

The Frog Prince Once upon a time … A spoilt princess played with her golden ball in the garden of her castle. She threw the ball over and over, but when she missed it the ball rolled away and splashed into a big pond.

“I am a frog,” said the frog. “I have no need for jewels and crowns. But if you give me a kiss I will fetch the ball.”

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“Oh woe!” said the Princess. “My beautiful ball is gone.”

“Okay,” said the Princess. “But fetch the ball first.”

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The princess could not reach the ball and watched in dismay as it sank beneath the water. She was not allowed to get wet, and besides, she couldn’t swim.

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“Or perhaps you could wear my crown?”

The frog dived down and soon brought the ball to the surface. Laughing happily, the princess grabbed the ball and tried to run away.

But the frog hopped in front of her. “What about my kiss? You made a promise.”

© ReadyEdPubl i cat i ons “Why you crying, princess?” The princess stopped and sighed. •aref o r r ev i ew pur p o s e s o n l y • “Must I?” The princess stared in surprise at the talking frog. “What do you care, you slimy creature?”

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“Tell me your problem and I may be able to help,” said the frog.

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The princess told the frog about her lost ball. Then she had a thought. “Perhaps you can dive down and fetch the ball for me?”

The frog waited patiently. Screwing her face up, the princess picked up the frog and kissed the frog’s forehead.

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Just then a frog popped up from under the water.

Instantly, the frog turned into a tall, handsome prince. He had been trapped in the frog’s body by a wicked witch. Now that he was free, he asked the princess to marry him.

o c . che e r o t r s super “And what would you do for me in return?” croaked the frog. “I will give you this jewel,” said the princess.

… and they lived happily ever after.

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Frog Stories 2

An Aesop’s Fable –

The Frogs and the Well

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Together the two frogs set out to find a new home. When they came to a deep well, one frog stood on the edge and looked down.

“This looks like a nice cool place, brother. Let’s jump in.” But the other, wiser frog, said: “Wait, brother. The well is deep and you can’t see if there is water at the bottom. If the well, too, has dried out, you will be stuck down there with no water.”

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Two frogs lived together happily in a swampy marsh, but when summer came the marsh dried up and the frogs were left without a home.

© ReadyEdPubl i cat i ons •f orr evi ew pur posesonl y• The moral of the

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story is “Look before you leap”.

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Frogs: Awesome Amphibians