DK Everything You Need to Know About Frogs and Other Slippy Creatures PDF

Everything you need to know about FROGS AND OTHER SLIPPERY CREATURES DK PUBLISHING LONDON, NEW YORK, MUNICH, MELBOURNE, and DELHI Senior editor Carrie Love Senior designer Claire Patané Design Hedi Hunter and Rosie Levine Editorial Holly Beaumont, Fleur Star, Ben Morgan, and Alexander Cox US editor Margaret Parrish Consultant Brian Groombridge Publishing manager Bridget Giles Art director Martin Wilson Creative director Jane Bull Category publisher Mary Ling Production editor Clare McLean Production controller Claire Pearson Picture researcher Rob Nunn Proofreaders Caroline Stamps and Lorrie Mack Jacket editor Matilda Gollon First published in the United States in 2011 by DK Publishing 375 Hudson Street, New York, New York 10014 10 9 8 7 6 5 4 3 2 1 001–180779–Aug/11 Copyright © 2011 Dorling Kindersley Limited All rights reserved under International and Pan-American Copyright Conventions. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. Published in Great Britain by Dorling Kindersley Limited. A catalog record for this book Can you is available from the Library of Congress. SEE ME? ISBN: 978-0-7566-8232-3 This high-casqued chameleon (Chamaeleo Printed and bound in China by Hung Hing hoehnelii) is superb at blending in with its surroundings. Find out Discover more at more about camouflage www.dk.com on page 17. CONTENTS 6 Amphibians 46 What’s for dinner? 8 Reptiles 48 Living fossils 10 What’s inside? 50 Snakes and ladders 12 Super skin 52 Horned lizard 14 Life cycle of a frog 54 Why did this woman turn 16 Colors and markings people into stone? 18 Home, Sweet Home 56 In search of the ﬂapping frog 20 Amazon horned frog 58 Defense techniques 22 How do crocodiles breathe 60 Travel blog underwater? 62 Lost and found 24 Parental care 64 Is it a bird? Is it a plane? 26 Biggest and smallest 66 Don’t look up 28 Sun seekers 68 How did frogs’ legs shock 30 Can you spot the fake? science? 32 The glass frog 70 How to survive an encounter with a crocodile or an alligator 34 Fancy feet 72 Working with amphibians 36 The water-holding frog and reptiles 38 Top 10 deadliest 74 How does this lizard 40 Sixth sense walk on water? 42 Gecko feet 76 Record breakers 44 The newt that never grows up 78 Glossary and index 80 Credits How does a fer-de-lance snake kill its prey? Discover its tactic on page 39. Ribbit, Which lizard is an insectivore? Take a look at page 46. scuttle, Why is the male midwife toad a hands-on father? See for yourself on page 25. How can you survive an attack from a crocodile or alligator? Read and REMEMBER the tips on page 71. 4 How far can a leatherback sea turtle travel? Take a journey with one on pages 60—61. Try to outstare a frog on pages How does a reptile obtain heat 30—31. One frog will always win, from its surroundings? Get a since it has a spot that looks like an eye! glimpse on page 28. slith r e Play a game of snakes and ladders on pages 50—51. Be careful, or you might slip down an inland taipan! When a frog sheds its skin what does it do with it? Discover the answer on page 13. Amphibians HOW MANY? There are about 6,800 species of amphibian, most Amphibians are animals of which are frogs. There are about 600 species of newt and salamander. that live PARTLY in water and PARTLY on land. Frogs, toads, NEWTS, and salamanders are all amphibians. REPTILES have dry, scaly skin, but AMPHIBIANS Fr og have soft, moist skin. Most spa amphibians can breathe through wn their skin, but only if it stays damp. Adult amphibians can Most amphibia also BREATHE ns breed in w ater. Unlike rep through lungs. tough-sh tiles, whic h lay elled eggs land, mos on t amphibi lay soft, je ans llylike egg in water. s 6 rog re ef Is a toa a t I have d d a frog I’m like it’s ry, lu mpy sk ? covered in that looks call me i n warts. P a toad, b eople us ut I’m r ually eally a f a river rog. Most frogs live near t in or pools of water. Bu mid rainforests, it is so hu the time, the trees are wet all to stay allowing some frogs. They in them permanently and have are called tree frogs to help huge, sticky ﬁngers them climb. Most baby amphibians live entirely in water. Called tadpoles, they swim like ﬁsh and breathe through gills. As they grow up, they develop legs and crawl onto land, but they must always be in wet places. tadpole poles When a f an eg g, ad s o u t o hatche n life is to s k i T t a its ﬁrst egg, a t ’s l e ft of its s. eat wh o f n utrient s fu l l which i s, the o s t a m phibian In m an c h a n g es into tadpole process called l t b y a adu is. e t a m orphos m 7 Reptiles HOW MANY? Lizards make up the largest group of reptiles (with 5,461 species), followed Today, there are more than by snakes (3,315 species), then turtles (317 species). There are fewer amphisbaenians (181 species), and even fewer crocodilians 9,000 reptile species (24 species). The smallest group is the tuataras (with just 2 species). on Earth; the major groups are alligators and crocodiles, Brightly colored Iguanas and their relatives make up some of the TURTLES, lizards, and most colorful of all lizards. This green iguana is snakes. ALL brightly colored with a few markings. All re p REPTILES are cold-blooded, have tiles backbo which is why they WARM THEMSELVES in the sun and nes have bodies covered in dry, HORNY SCALES. Some reptiles lay eggs; others Bright lines give birth to The red markings on a Madagascan giant day gecko vary between individuals. 8 live young. Reptiles vary greatly in shape and size. However, all reptiles have scales in contrast to the smooth, moist skin of amphibians. Scales differ among species, but they are a defining feature of a reptile. Legless and long Snakes are legless reptiles. They’re found all over the world, but they don’t do well in cold places. The Common boa constrictor, such as the one shown here, can grow to 3–13 ft (1–4 m)! Light like sand Like many geckos, this Sandstone gecko is colored to blend in with its surroundings. Tuataras are a group of reptile found only in New Zealand. 9 What’s inside? FROGS have simple skeletons with fewer bones than other vertebrates (animals with backbones). They tend to have robust bodies and strong hind limbs. Most frogs have protruding eyes and no tail. Take a look at what’s under a frog’s skin. Skull Frogs tend to have broad heads with large sockets for the eyes. The hands and ﬁngers of frogs vary They usually have short according to lifestyle. Climbing frogs spines and no ribs. need ﬁngers that can grip well. Hand Heart CHAMBERS Frogs have a developed nervous system that is made up of a brain, nerves, and a spinal cord. A frog’s heart has three chambers, whereas a mammal’s has four. A frog’s brain is structured in a similar way to a human’s brain. The cerebellum (region on the top of the brain) controls posture and muscular coordination. Elongated ankle bone Toe bone A frog’s bone structue helps it jump a long way. The tibia (shin bone) and ﬁbula (calf The legs and feet of frogs vary depending bone) are fused into a single, on where they live. Frogs that live in water strong bone. have webbed toes. The more time they spend 10 in water, the more webbed their toes are. SNAKES have incredibly LONG necks. The neck takes up one-third of their length. Their organs are also long and fit in one behind the other. The heart is encased in a sac, but it’s not fixed in place, preventing damage when swallowing a large animal. Snakes have strong skulls with a solid and complete braincase. Skull Trunk Dry SKIN vertebra Snakes have dry, smooth skin that is covered in scales. They shed their skin regularly. Ribs When they shed their skin it Longer species have as many as comes off as a whole layer and 400 vertebra along their backbones. is often intact. Smaller snakes have 180. Snakes have really ﬂexible lower and upper jaws, allowing them to stretch their mouths open Snakes have ﬂexible spines and strong wide to eat prey that is often trunks that allow them to move in a wider than their own heads. wavelike pattern. Tail vertebra 11 Frogs have very special skin. They don’t just FROGS don’t usually SWALLOW water like we do. Instead, they absorb most of the moisture they need through their skin. They also get water from prey that they eat. Their skin is used to get extra oxygen from the water (in addition to the oxygen that’s come into their lungs via their mouth cavity). Because frogs only get oxygen through their skin when it’s moist, they need to take good care of it or they might suffocate. Some frogs are slimy. This is because their SKIN secretes a 12 mucus that stops it from getting dry. wear it, they also drink and breathe through it! Frogs regularly shed their outermost layer of skin cells to keep it healthy. This looks pretty yucky. They start to twist and turn and act like they have the hiccups. They do this to stretch out of their old skin! Finally, they pull the skin OFF over their head LIKE A SWEATER, and then (this is gross) they EAT IT! Eeeeewww! 13 Life cycle of a frog From a baby tadpole to a young frog Life begins Tiny tadpoles A male and a female frog come When an egg hatches, a tadpole’s together to mate. Eggs are laid mouth, tail, and external gills are in clumps or strings. An egg not fully developed. At about seven hatches about six days after it’s to 10 days, a tadpole begins to feed been fertilised. At ﬁrst it feeds on on algae and attaches itself to weeds. the remains of the yolk. Fully formed Between 12 to 16 weeks a frog has completed its growth cycle. The timing varies between species and on the food and water supply. A fully formed frog starts the process afresh by mating. 14 Getting bigger At four weeks the external gills are covered by body skin. They eventually disappear and are replaced with lungs. Tadpoles have tiny teeth that help them to chew away at plants and algae-covered surfaces. A bit of both Tiny legs start to form from six to nine weeks. The head becomes more obvious. The arms begin to come out, with the elbows showing ﬁrst. After nine weeks the tadpole is beginning to look more like a frog. Nearly there! By 12 weeks the young froglet only has a small stub of a tail. It looks like a smaller version of an adult frog. Soon it will leave the water to live on the ground. 15 COLORS and G S AMPHIBIANS and REPTILES MA R K I N have a variety of markings and colors. The spectrum ranges from bright reds and blues to Texas coral snake Markings can be muddy greens and BROWNS. deceptive! Milk snakes have thin black bands, and Some have spots, while thick yellow and red bands. They aren’t poisonous, but they appear to others have stripes. be dangerous because their banding is so similar to venomous coral snakes. Fire salamander Regal Red-eyed tree frog ring-neck snake 16 Southern dwarf Colorful CAMOUFLAGE chameleon The pattern and color of an amphibian or reptile can help it to blend in with its surroundings to hide from predators. Chameleons, as their name suggests, have an amazing ability to hide themselves by changing their appearance. They can alter their color as well as their markings. Strawberry poison-dart frogs are Collared bright red. This acts to warn other creatures that their lizard skin secretions are highly toxic. Hide and seek The Paciﬁc tree frog is able to blend into its surroundings very easily. It reacts to seasonal changes and can switch its coloring from brown to green. It can also change its markings and the lightness of its skin according to the shift in background brightness. 17 Home, Sweet Home Amphibians are found on all continents except Antarctica. Nearly all amphibians live in or near wet areas such as streams, rivers, ponds, lakes, and other wetlands, but some display amazing adaptations that allow them to live in dry, dusty deserts. Many adult amphibians spend their lives on land, but nearly all need to lay their eggs in water. Desert LIVING Plant LIFE Up in the TREES The red-eyed tree frog The female strawberry poison-dart (Agalychnis callidryas) lives high up frog (Oophaga pumilio) lays her eggs in rainforest canopies in Central The desert tortoise (Gopherus agassizii) on a leaf. When the tadpoles hatch, she America. It is also known as the spends about 95 percent of its life moves them to a water-ﬁlled location. “monkey frog” because of its underground. It can go a year without water. excellent climbing skills. Couch’s spadefoot toad (Scaphiopus couchii) gets its name from its feet, which The tree hole frog (Metaphrynella help it to dig down through loose sand. It sundana) is a native of lowland lives underground during dry months. The gold frog (Brachycephalus forests in Borneo. It lives in the didactylus) makes its home in mountain hollows of tree trunks. The little The sandﬁsh rainforests. It mainly lives among leaf frog uses tree hollows to amplify (Scincus scincus) lives litter. It is a ground-dweller, since it can’t its mating calls so that it can be in Africa’s Sahara jump or climb very well. The female lays heard over long distances. desert and is famous eggs that hatch directly into small frogs, for its ability to missing out the tadpole stage. “swim” through sand. Who lives in a dry place? Many reptiles Who lives in a “house”? Some frogs Who lives up in the trees? Most live in deserts. They can hide from the have adapted to live in dead leaves that of the world’s frogs live in tropical extreme temperatures in burrows. The desert have fallen onto the forest ﬂoor whereas rainforests, where the temperature is the last place you might expect to ﬁnd an others cleverly use leaves to hide their is nice and high and there is plenty amphibian, but a few species have adapted to eggs in until they hatch. of water. this extreme environment. 18 Reptiles don’t exist in Antarctica either. Unlike amphibians, they have watertight skin. This means that they don’t dry out as quickly. Some reptiles live in hot, dry places such as deserts. Others live in warm swamps, rivers, or forests. A few have even adapted to a life at sea, but all return to land to lay their eggs. All at SEA In the WET Cool CREATURES The yellow-bellied sea snake (Pelamis The African clawed frog (Xenopus The wood frog (Rana sylvatica) platurus) has the largest lung of any snake. laevis) lives in ponds, lakes, or streams survives freezing conditions by This helps it to control bouyancy so it can in southern Africa. It spends most of hibernating. It ﬁnds cracks in rocks, stay under water for long periods of time its time in water. or gaps in logs, or can bury itself in (up to three and a half hours). leaves, to get through the cold winters. Northern water snake (Nerodia sipedon) lives in and around streams, ponds, lakes, and The hawksbill turtle (Eretmochelys Slow worm (Anguis fragilis) is marshes. Water snakes are good imbricata) uses its narrow beak to a legless lizard that hibernates in swimmers. They have been known forage for mollusks, sponges, and piles of leaves, or in hollows to herd tadpoles to the water’s edge other animals. between tree roots. It goes to sleep before tucking in. in October and emerges in March to breed in early summer. Who’s that in the sea? Amphibians Who likes to live somewhere Who’s hiding from the cold? Some can’t cope with seawater because their moist? Amphibians provide tasty reptiles and amphibians live in skin is too thin to protect them from meals for many reptiles, so where they temperate parts of the world, with cold all the salt. Reptiles have thicker skin live you will often ﬁnd reptiles, too. winters. One of the ways in which and a few species can regulate the salt The Northern water snake lives near they can survive these cold months is in their blood and are therefore able to ponds, where it can catch amphibians. to save energy by hibernating. live in the sea. 19 Amazon horned FROG Famed for its big appetite and its bad temper, the Amazon horned frog can grow to reach the size of a small dinner plate. ENORMOUS GAPE With a mouth that is wider than the length of its body, the Amazon horned frog can gobble up prey almost as big as itself. Patient PREDATOR Amazon horned frogs are voracious carnivores. They ambush their prey by sitting quietly and waiting for it to approach, before striking with a sudden snap of their jaws. Amazon horned frogs aren’t picky eaters. Mostly they live on a diet of ants and other insects, but they will try to eat any animal smaller than themselves, including mice and, occasionally, rats. They don’t always get it right, and may try to take on an animal that is too big for them to stomach. Watch your feet! The Amazon horned frog will sometimes defend itself by attacking people if it is disturbed. They tend to grab anything that comes near them that could be edible. 20 Impressive HORNS FROG FACTS As its name suggests, the Amazon horned frog has big ﬂeshy horns above its eyes. These are the largest horns of any of the horned frog species. These · Unlike other tadpoles, the pointed brows help to disguise the Amazon horned frog tadpoles frog’s shape as it sits among are predatory from the start. When they hatch, they attack the leaves on the forest ﬂoor other tadpoles and even attack awaiting its prey. each other. · Females lay up to 1,000 eggs! They lay their eggs around aquatic plants. · Males are slightly smaller than females. They make a mating call that sounds like a cow lowing (making a “moo” sound). This frog grows up to 8 in (20 cm) in length. 21 How do crocodiles breathe underwater Crocodiles have an amazing ability to breathe and hunt underwater at the same time. By closing a flap of skin at the ? back of their throats they prevent water from flowing into their lungs. They hold air in their lungs until they resurface. They are able to keep their mouths open to grab prey Saltwater underwater, although they usually move to land to swallow crocodile (Crocodylus it. They also have flaps that can be closed over the nostril porosus) and ear openings. TURTLES Aquatic turtles breathe through their lungs. The Florida softshell (right) has to surface and Florida use its snout to fill its lungs with softshell turtle oxygen above water. Some turtles (Apalone ferox) manage to stay underwater for weeks, living on very low oxygen levels. 22 Crocodiles can waterproof their eyes with a SEA SNAKES Sea snakes can stay underwater for up to five hours. They have an enlarged lung that helps them to store lots of oxygen for when they’re underwater. FROGS They have to resurface to breathe in Frogs can breathe more oxygen before they can make through their skin when they’re another dive. Banded sea snake in the water. Their skin absorbs Okinawa frog (Laticauda (Rana sp.) oxygen from the water around colubrina) them. Find out more about their amazing skin on pages 12–13. CROCODILIANS have a FLAP of tissue behind the tongue that covers their throats when they are submerged in WATER. membrane that acts as a transparent shield. 23 AMPHIBIANS and REPTILES have different ways PARENTAL CARE ofbringing their young into the world. Most hatch from an egg. Amphibian eggs However, many amphibians A lot of choose a sheltered amphibians lay egg-laying location their eggs in water, where they guard their where they develop eggs or protect them into tiny tadpoles. in a layer of foam. Other amphibians carry eggs on their backs, in their vocal sacs, in skin pockets, or even in their stomachs! Most Reptile eggs lizards lay eggs. They Alligators rarely return to and caimans their nests, although make their nests some skinks stay with from mounds of soil their eggs to help and leaves. Crocodiles maintain moisture and gavials lay their and warmth. eggs in holes they The shells dig in sand or dry, of eggs laid by crumbly soil. most turtles and tortoises are hard, but the shells of marine and river turtle eggs are softer. 24 Father FIGURES In some species of frog, the father plays a key role. The male Darwin’s frog takes care of the eggs as they The male midwife develop. When the tadpoles toad (right) shows an hatch, he puts them in his interesting form of care. The vocal sac, where they female lays the eggs, but the male grow until they are carries them on his legs! After about released as three weeks, the male takes the tiny frogs. eggs to water, where the tadpoles hatch. The Boy gender of baby or crocodiles, a caim an girl? turtles, and When b orn, i t tortoises is often l l i g a tor is t h er. or a ts mo determined by c l o se to i r e stay s es a egg temperature reptil rs in oung mothe during The y b y t h e i r ives. d l protec te f their incubation. Absent PARENTS the ea rly we e k s s o detect ed the y e r i The majority of geckos lay their eggs in dang r as a When mothe u s e their n der bark or in the crevices of rocks. Geckos DO can ing u i e l d by hid NOT take care of their young. The young are sh dy. her bo self-sufficient from birth. Turtles lay the most eggs out of all reptiles, but they don’t watch over them. The eggs are left in soil or sand and when the baby turtles emerge, they are on their own. They have to learn survival skills pretty quickly! 25 UA L T AC ZE SI from this......................................................to this! The GOLIATH FROG starts out SMALL. Its tadpole is the same size as that of the keeps on average frog, but it growing until it reaches the size of a cat. With legs outstretched, the frog can MEASURE almost 3 ft (1 m) in length. 26 The goliath frog (Conraua goliath) lives in western Africa. It is found across a narrow range of Equatorial Guinea and Cameroon, in and around fast-flowing rivers and waterfalls. It is a popular food for locals. Goliath frog The goliath frog is the largest anuran (the class How small? of animal that includes The smallest frog in the world is the Monte frogs and toads). Iberia frog (Eleutherodactylus iberia) of Cuba. This tiny amphibian reaches a full size of only ⅓ in (9.8 mm) from snout to vent. It would sit comfortably on one of your fingernails. Smallest frog The Monte Iberia frog breeds by direct development, missing out the tadpole stage altogether. 27 seekers Reptiles are cold-blooded animals, although once they have sunbathed their blood is about the same temperature as ours. Most reptiles live in warm climates, as they rely on their surroundings to obtain heat. eir e e p th e at a sk ur o e p tile perat ving t R m o l te ym t e rna level b e. in t ad n s tan the sh co m d fro a n eat o b t ain h lso t i l e can a lly on a r e p it s b e A sting by re rock. warm 28 If the temperature doesn’t suit a reptile then some Air ºC ºF temperature 45 110 In the summer months, reptiles Lizard’s body that live in tropical areas are temperature 90 30 inactive in the middle of the Sheltered to avoid cold day, since it’s too hot to move. 70 Basking 15 50 Normal activity 0 32 Sheltered to 6 am 9 am 12 noon 3 pm 6 pm 8 pm This graph shows the avoid heat ACTIVITY PATTERNS activity levels of a lizard. Take a look at how and where it spends its day. Reptiles need to stay warm when they eat. A snake that has eaten a meal but cannot get to a warm place might die if the food in its stomach is too cold to digest. species will hibernate until the temperature is right. 29 Can you spot the FAKE? FROGS use their MARKINGS for protection against predators. One of the frogs shown here has a cleverly positioned eyespot that helps it to confuse any potential ATTACKERS. Can you tell which one it is? 1 2 5 6 9 10 30 31 12 11 8 7 4 3 Answer: the fake eye is number 7, which is actually the back of a dwarf frog. Here are the names of the other frogs: 1. Dumeril’s bright-eyed frog 2. Common big-headed frog 3. Water-holding frog 4. Poisonous tree frog 5. Smoky jungle frog 6. Mossy frog 7. Dwarf frog 8. Long-nosed horned frog 9. Red-eyed tree frog 10. Bronze frog 11. American bullfrog 12. Red-eyed tree frog FROG With its amazing see-through body, the glass frog blends in perfectly with its surroundings. This little frog hangs on to leaves with tiny, round–ended toes that seem almost to melt into the leaf surface. It lives in Central and South America. THE 32 1–3 in (3–7 cm) Glass frogs are more transparent from beneath. You can even see their hearts beating busily in their chests. Glass frogs lay their eggs on leaves that overhang running water. The male frog stands guard and protects the eggs MOST GLASS from parasitic ﬂies. FROGS live high in THE rainforest CANOPY. At such a height, the trees are covered with clouds all year round and the frogs’ skin is kept nice and moist. When the tadpoles hatch, They come down from the canopy they drop down into the water. They have powerful to lay eggs. tails and are well-adapted for life in fast-ﬂowing forest streams. 33 There is only one known surface a gecko can’t stick to: Teﬂon®. (That’s the shiny black plastic used to coat nonstick pans.) Fancy colorful famil feet G EC m o st d yo an KO f li Sa t es re the larg zards, Some geckos have wi claws at the ends 2,0 th of their toes. The e ci es. 00 sp claws are known retractable (they can be pulled back in on demand). There are half a million hairs on a gecko toe! 34 The special pads on a gecko’s feet are self-cleaning. Dust or dirt in the hairs might stop them gripping. Fortunately, dirt easily drops off a gecko’s scaly skin. ing. e il c s id e d own o n the k up izes. They can wal come i EET n ir F a ll e Th ap e sh s and s If an average-sized, 2½ oz (70 g) adult gecko had every hair on its feet in contact with a surface, it would have enough force to lift a 290 lb (133 kg) weight. 35 WATER- H LDING This frog is bloated with all the water it has consumed. Where does it LIVE? W The water-holding frog (Litoria platycephala) lives in Australia. During T the rain rainy season, the frog absorbs water and in doing so puts on 50 percent of its own body weight! To keep from losing this water during the dry months, it creates an underground home to stay in. Since the mud is still wet from the rainy season, its able to burrow down more than 3 ft (1 m) beneath the surface. It enters a summer hibernation and can stay underground waiting for the next rainy season. When it senses the water from heavy rains, it wakes up and starts to resurface. STORING water S The water-holding frog stores water in its bladder and beneath its skin. T “Living WELL” “ Aborigines used to dig up the frog to extract drinking water. They used A the frog th f as a “living well.” To gain access to the water they squeezed the frog. FEEDING time F W When active above the ground, it lives in water bodies. It feeds on other ffrogs, ttadpoles, and small insects. EGG laying E A female usually lays more than 500 eggs at one time! She lays her eggs and then the goes into a hibernation. She enters this state in order to prevent damage from extreme dryness and heat. 21⁄3 in (6 cm) Widespread in Australia 36 The term for a water-holding frog’s “sleep” is Before... After... In its normal state, a When it has consumed half water-holding frog is just its own body weight in 21⁄3 in (6 cm) in length. water, its body is enlarged to 41⁄2 in (12 cm) in length. When active, it lives in puddles, pools, and streams. estivation. It usually happens in the summer. 37 TOP 10 DEADLIEST ST Most reptiles and amphibians are perfectly D LIE AN A DE HIB P I harmless to people, but a few can inflict A M lethal bites or kill with a touch of their poisonous skin. Here are some of the world’s deadliest cold-blooded killers. ! rt FROGbia can kill Poison darib ilis of Colom Phyllobates ter y Just one of these tin you if you touch it. aly ze h poison to par frogs contains enoug and kil l 50 peo ple. Th e deadly Inland TAIPAN skin comes The inland taipan (Oxyuranus chemical in the frog’s s pla nts , which are microlepidotus) of Australia has the from poisonou ts tha t are in turn eaten deadliest venom of any land-dwelling eaten by an ples snake. The venom, injected by a bite, not by the frog. Native peo poi son only poisons nerves, but also causes the use the frog to make victim’s blood to clot, blocking arteries. blowpipe darts. Before an antidote was developed, there were no known survivors of a taipan bite. Fortunately, the taipan is very shy and bites are rare. Australian brown SNAKE The eastern (or common) brown snake (Pseudonaja textilis) of Australia is the world’s second most venomous land snake after the Taipan, based on the Saltwater CROCODILE strength of its venom. Its bite is usually fatal, unless The saltwater crocodile (Crocodylus porosus) of Australia and the victim receives an antidote. The venom contains parts of Asia is the largest reptile on Earth, with big males weighing potent nerve toxins, which paralyze the victim’s more than a ton. Normally seen basking lazily in the sun or wallowing muscles, and chemicals that make the blood clot. in shallow water, it is capable of explosive bursts of speed when attacking. It drags its victim into the water and then rolls around to tear the body apart. ! 38 Nile CROCODILE The Nile crocodile (Crocodylus niloticus) of Africa kills a large number of people, since locals often collect water or wash from the river. It sneaks toward victims with its body hidden in the muddy water and only its eyes above the surface. It then leaps out and snatches the victim in its jaws before dragging them in the water. Komodo DRAGON The world’s largest lizard, the Komodo dragon (Varanus komodoensis) weighs as much as a man and can attack and devour a human being. The lizard kills prey in an especially gruesome way, biting victims with ﬁlthy teeth that are covered with disease-causing bacteria. The victim may escape, but the bite turns into a festering wound that can kill. ! DE A LI DLI ZA ES RD T Eastern diamondback RATTLESNAKE The bite of North America’s deadliest snake can kill in a matter of hours. The Eastern diamondback rattlesnake (Crotalus adamanteus) venom contains hemotoxins, which attack the blood and damage a huge area of tissue, potentially leading to loss of a limb or death. Thanks to rapid treatment with antivenom, only a handful of deaths occur each year. Puff ADDER This bad-tempered African snake is called the puff adder because it hisses and puffs when approached, while curling itself into a tight S-shape, ready to strike. Get too close and it will lunge forward and sink its long fangs deep into your skin, injecting a venom that attacks the blood. The puff adder (Bitis arietans) causes more deaths than any other snake in Africa. Fer-de-LANCE This South American relative of the rattlesnake preys on rats and other rodents, killing them by injecting venom through its hollow teeth. The fer-de-lance’s (Bothrops atrox) venom is packed with enzymes that destroy blood cells and body tissues, causing ﬁts of vomiting, diarrhea, paralysis, and blackouts. Black MAMBA The bite of the black mamba (Dendroaspis polylepis) kills in less than an hour, and without antivenom is almost always fatal. The lethal ingredient in the venom is dendrotoxin, a chemical that paralyzes muscles and stops the lungs and heart from working. Death is usually caused by suffocation. 39 Bamboo pit viper The heat pit in a python has one section. In a pit viper, it has two sections. The inner one is the temperature of the snake and the outer one heats up when the snake is near a heat source. Sixth sense SNAKES such as pythons, pit vipers, and some BOAS are able to PICK UP small changes in air temperature around them by using organs on their faces, called heat pits. They detect these changes as infrared rays (heat vision). This sixth SENSE allows them to locate prey during the night. This royal python (Python regius) sees a thermal image in its brain that allows it to track prey quickly and efﬁciently. Royal python 40 This system is so precise that pit vipers can notice The FIVE senses HEARING Snakes do not have external ears. Their hearing is poor so they rely on vibrations from the ground that pass through skull bones on their lower jaws to their ears. This puff adder (Bitis arietans) is sticking close to the ground to sense any vibrations. SIGHT Snakes generally don’t have great vision, although they are adept at detecting movement. The vine snake (Ahaetulla nasuta) is unusual in that it has forward-facing eyes that give it binocular vision and a good sense of distance. TASTE The Jacobson’s organ enables snakes to taste and smell. The organ consists of two sensitive cavities in the roof of the snake’s mouth. Their tongue gathers particles that the organ analyzes. Snakes that live in water, such as the green anaconda (Eunectes murinus) are able to use their tongue to gather particles underwater. SMELL Snakes use their sense of smell to help them locate prey. The common boa constrictor (Boa constrictor) detects its prey through scent and taste. Using its Jacobson’s organ it is able to work out if prey is nearby. Boas wrap their coils around their victims and squeeze hard to kill them. TOUCH From the beginning of a snake’s life, it relies on touch for guidance. It uses its tongue and pressure receptors in its skin to touch objects, move, and orientate itself. The Indian python (Python molurus) is using its tongue to explore its surroundings. changes in temperature that are less than a degree. 41 GECKOS are small lizards There’s more to a gecko’s Gecko FEET but they’ve set humans a feet than hair. Their toes gecko’s toes. They even inspire science. bend backward (compared BIG challenge: to mimic to ours), and they must “peel” them off a surface a their amazing ability to bit at a time. It’s like walk up WALLS. Their Velcro—it won’t slip! secret ? BILLIONS of tiny hairs (called setae), and long toes to help a lizard grasp the bumps. Fan-ﬁngered The toe-pads on fan-ﬁngered geckos are gecko split into two parts. This gives them extra grip, even compared with Nothing GOES like a other geckos. When SCIENCE copies There are 14,000 hairs nature, in 1 mm² of a gecko’s it’s called biomimetics. foot. Each hair has between 100 and 1,000 ﬁlaments that grip onto the wall as it climbs. 42 STICKYBOT is a robot that can climb SMOOTH SURFACES such as glass. HOW? one animal. Stickybot STICKYBOT uses 12 motors to mimic Stickybot’s feet have rows of stiff, yet ﬂexible “gecko tape” on them. This material produces a sticky force that allows the robot to climb up windows and whiteboards. 43 The newt that This captive-bred axolotl looks like an albino—with no pigment in its skin—but since it has pigment in its eyes it’s called “leucistic,” which means reduced pigment. “Wild-type” axolotls are usually dark. Wild axolotls are only found in the canal systems of Mexico’s Lake Xochimilco. Located close to Mexico City, these canals are threatened by pollution and increased development. Axolotl means “water-dog” in 44 ow s U P ne ver gr The axolotl is the Peter Pan of the animal world. It doesn’t undergo metamorphosis like many other amphibians. Instead, it spends its entire life in a juvenile form, keeping it gills and ﬁns, and living in water. The axolotl grows steadily bigger until it is old enough to reproduce. Though their numbers are falling in the wild, many axolotls are kept in captivity. Axolotls are popular pets, but they are also studied by scientists because of their interesting life cycles and their powers of regeneration—axolotls can regrow entire limbs. In captivity it is sometimes possible to make the axolotls metamorphose by injecting them with special hormones that trigger growth and development. In their adult form, they look very like their near-relatives, the tiger salamanders. the ancient language of the Aztecs. 45 What’s for dinner? The Gila monster stores fat in its thick, stumpy tail. It is this energy store that allows it to survive for months without food. The binge-eater Lizards for starters The Gila monster (Heloderma suspectum) Most lizards are insect-eaters only eats between 5–10 times a year, but (insectivores), but some have special when it does, this lizard can consume the equivalent of over half of its diets. Some big lizards are carnivores body weight. It mainly eats and eat animals such as birds, the eggs of birds or rodents, or other lizards. A few other reptiles. lizards are plant-eaters (herbivores). The insectivore The Sinai agama (Pseudotrapelus sinaitus) is a slender lizard. It has long, thin limbs, which make it good at running over the hot sand when it hunts in the heat of the day. It feeds on ants and other insects, but it also eats sand! The vegetarian One plant-eating lizard is the green iguana (Iguana iguana), which survives on a complex diet of leaves, shoots, flowers, and fruit. It can’t digest animal protein well, although it may sometimes accidentally eat small insects and other invertebrates that are attached to vegetation. The cannibal The American bullfrog (Rana catesbeiana) is the largest of the North Frog food that moves American frogs, growing up to 8 in (20 cm) in length. These frogs are voracious eaters Most frogs are carnivorous. Nearly all of and will eat anything they can fit into their them eat insects and other invertebrates exceedingly large mouths. This includes like worms, spiders, and centipedes, but insects and other invertebrates, rodents, some of the bigger frogs take on larger birds, snakes, and even other bullfrogs. prey, such as mice, birds, or other frogs. 46 Sea turtles The diet of sea turtles varies between The jelly-eater species. Some eat a wide range of foods, Leatherback turtles (Dermochelys coriacea) are the biggest turtles in the world. They live on both plant and animal, but others have a diet of jellyfish and comb jellies, both of which special diets, with adaptations that make are made up mostly of water. To get enough it easier to eat particular things. energy and nutrients to grow so big, leatherbacks eat huge quantities of food—they sometimes eat their own weight in jellyfish each day. The cruncher Loggerhead turtles (Caretta caretta) mainly eat hard-shelled creatures such as crabs, conchs, and clams. Their big heads and strong jaws help them to crush the shells and they can hold their breath for up to 20 minutes on their dives down to the sea floor. The fruitivore Izecksohn’s Brazilian tree frog (Xenohyla truncata) is one of the very few plant-eating (herbivorous) frogs. Living in bromeliads in the Brazilian coastal moist forest, it eats brightly colored berries from arum plants and fruit from the cocoa tree. The frog helps to disperse plant seeds in its poop. The sponge muncher Hawksbill turtles (Eretmochelys imbricata) live around coral reefs, rich in marine life. They can eat a range of prey, but they mainly live on a diet of primitive, plantlike animals called sponges. The turtles are named after their sharp, birdlike beaks that make it easier for them to reach sponges growing in crevices between rocks and corals. The mite-y eater Poison dart frogs use poisons in their skin to deter potential predators. They get their poisons from their food. The strawberry poison-dart frog (Oophaga pumilio) gets its toxins from a mite that lives in the soil in Central and South America. The frog also eats other small invertebrates. As the frog eats its food, the toxic chemicals build up in its body, which makes it more poisonous. 47 L I V I N G FOSSILS The giant salamanders of China and Japan are the world’s largest amphibians. While most salamanders would fit in the palm of your hand, giant salamanders grow bigger than your arm—and some longer than the length of your entire body. NO ONE KNOWS how long giant salamanders live in the wild, but the oldest captive salamander lived for 52 years. GIANT salamanders have changed very little in the last 30 million The Chinese giant salamander (Andrias davidianus) is the Chinese giant world’s largest amphibian, growing up to 6 ft (1.8 m) in length salamander in captivity. It is heavily built, with a ﬂat head and a wide mouth. Like its Japanese cousin, it lives a completely aquatic existence and its short legs cannot support its body weight when it is out of the water. Giant salamanders are paler on their undersides. 48 Skeleton of a Chinese giant salamander Stressed-out salamanders can produce a thick, Giant salamanders live in hollows in the banks of smelly mucous that makes them very streams and rivers. At night, they walk slowly along unpleasant to handle. the bottom, feeding on ﬁsh and crustaceans. They have a powerful bite and they catch their food with a quick sideways snap of their wide, many-toothed mouths. What a stink! years, which is why they are described as “living fossils.” The Japanese giant salamander (Andrias japonicus) is the second-largest amphibian, growing up to 5 ft (1.5 m) in length. The Japanese and Chinese salamanders breathe through their skin. Their skin has folds and wrinkles that increase the surface area, allowing more oxygen in. They like to live in clean, fast-ﬂowing streams but numbers of both species have dropped owing to pollution and dam building. Japanese giant salamander 49 Snakes & & YOU’VE WON! Ladders 100 99 You discovered a new antivenom. Go forward 5 places. 81 82 You mistook a slow worm for a 79 snake. Go back 2 places. 80 Are you feeling LUCKY? Challenge a 61 62 friend to a game of snakes and ladders and see who gets to the top first. BE CAREFUL not to step on a 60 59 snake—the ones in this game 42 43 all have deadly bites! 41 You will need: 39 38 * One or more friends to play with * A small object to use as a counter for each person * A die 40 How to play: To decide who starts, everyone rolls the die and the person with the highest number goes ﬁrst. When it’s 21 22 your turn, roll the die and move your counter along by the number. If you land on the bottom of a ladder, climb Coastal taipan to the top of the ladder. If you land on the top of a snake, slither down to the square at its bottom. If you roll a six, take another turn. The ﬁrst person to pass 100 wins. 20 19 Good luck! START HERE 1 2 50 Hog nose A spitting cobra spat in your eye. 91 viper Go back two places. 98 97 96 95 94 93 92 83 Black tiger snake 87 Death adder 89 84 85 86 88 90 75 72 78 77 76 74 73 71 66 67 68 69 70 63 64 65 Beaked sea snake 58 57 56 55 54 53 52 51 3 Death adder 47 You got rattled by a rattlesnake. Go back one place. 44 45 46 48 49 50 33 37 36 35 34 32 31 24 27 28 You wrestled Inland an anaconda and taipan won. Go forward 23 25 26 29 3 places. 30 13 12 18 17 16 15 14 11 You got squeezed by a boa constrictor. Go 3 4 5 back 3 places. 6 7 8 9 10 51 Horned lizard Built like miniature armored tanks, horned lizards move ponderously along the baking ground of their dry desert habitats; stopping to sunbathe, dig burrows, and snack on ants. They have evolved a range of adaptations to help them survive. 52 Bloody DEFENSE

DK Everything You Need to Know About Frogs and Other Slippy Creatures PDF

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