原版英语RAZ 教案Ostriches - Giant Birds.pdf

《原版英语RAZ 教案Ostriches - Giant Birds.pdf》由会员分享，可在线阅读，更多相关《原版英语RAZ 教案Ostriches - Giant Birds.pdf（9页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、www.readinga-Ostriches:Giant BirdsGIANTS OF THEANIMAL WORLDVisit www.readinga- for thousands of books and materials.Written by Jeff BucknerOstriches:Giant BirdsA Reading AZ Level X Leveled BookWord Count:1,284LEVELED BOOK XLEVELED BOOK XWritingShould ostriches be kept in captivity?Why or why not?Wri

2、te a persuasive essay for or against keeping ostriches in captivity.Use information from the book to support your opinion.ScienceResearch two other birds.Write a report describing how these birds are similar to and different from the ostrich.Connectionsadaptedcourtsdefensivedominantgrazehostileinden

3、tationomnivoresplumesprehistoricsavannatorsoWords to KnowOstriches:Giant BirdsGiants of the Animal WorldLevel X Leveled Book Learning AZWritten by Jeff BucknerAll rights reserved.www.readinga-CorrelationLEVEL XS4040Fountas&PinnellReading RecoveryDRAwww.readinga-Written by Jeff BucknerWhat characteri

4、stics enable ostriches to survive in the harsh conditions of the African savanna?Focus QuestionFront and back cover:Ostriches can cover 10 to 16 feet(35 m)in one stride.Photo Credits:Front cover,back cover:blickwinkel/Alamy;cover icon:Elena Belyakova/iStock/Thinkstock;title page:ElizabethHoffmann/iS

5、tock/Thinkstock;page 3:Marclschauer/iStock/Thinkstock;page 4(left):syntika/iStock/Thinkstock;page 4(right):iStock/filo;page 5:Frans Lanting/National Geographic Creative;page 6:Clem Haagner/;page 7:Prisma Bildagentur AG/Alamy;page 8(top):Science Photo Library/Science Photo Library/Superstock;page 8(b

6、ottom):Nigel Pavitt/JAI/Corbis;page 10(left):Pixworld/D;page 10(right):Bouncy/Alamy;page 11:ottoduplessis/iStock/Thinkstock;page 12(left):Johncarnemolla/D;page 12(right):Marccophoto/iStock/Thinkstock;page 13:Duncan Noakes/D;page 14(top):Darya Prokapalo/D;page 14(center):Putut Handoko/123RF;page 14(b

7、ottom):Ayan Dakshi/Alamy;page 15:Christophe Courteau/Nature Picture Library/CorbisOstriches:Giant Birds34How Big Is It?How Big Is It?Table of ContentsWhat Is It?.4Ogling the Ostrich From Claw to Tiny Head .5 Ostriches and Dinosaurs .7Ostrich Territory Ostrich Origins .9 Home,Home on the Plains .10Ve

8、ggies with a Side of Stones .11Ostrich Enemies .12Living Large .13Odd Duck and Scientific Wonder .15Glossary .16What Is It?When we think of birds,we usually imagine small,delicate creatures that fly,sing sweet songs,and live in tiny nests in trees .but then theres the ostrich.If you were to look at

9、a picture of ostrich legs without knowing what you were looking at,you might first think they were the legs of a reptile or prehistoric creature.So,exactly what kind of animal is an ostrich?Ostriches are the worlds largest living birds.Even though they cant fly,are the opposite of small and fragile,

10、and can make loud,hair-raising sounds,they are still birds.As adults,ostriches are giganticfar bigger than the tallest human beings.These“little birdies”are powerful and can expertly defend themselves against some of the fiercest animals in the wild.Ostrichheight:9 feet(2.74 m)weight:350 pounds(158.

11、8 kg)Humanheight:6 feet (1.8 m)weight:175 pounds(79.4 kg)Ostriches:Giant Birds Level X56Ogling the OstrichFrom Claw to Tiny HeadMost birds have four toes on each footbut not the ostrich,which has only two.It also has a secret weapon:a claw on the inside toe of each foot.This feature enables the ostr

12、ich to dig firmly into the ground and run faster than any other two-legged animal on Earth.With the help of extremely powerful legs,an ostrich can sprint up to 45 miles per hour(72.4 kph).It can maintain speeds of up to 30 miles per hour(48.2 kph)for long periods of time.In a single stride,an ostric

13、h can cover between 10 and 16 feet(35 m).An ostrichs wing and torso feathers are another of its distinguishing characteristics.Most birds feathers hold tightly together to enable them to fly.Since an ostrich doesnt fly,its feathers are not as rigid as those of many other birds;in fact,theyre soft an

14、d fluffy.An ostrich uses its wings for balance,which helps it run exceptionally well and make very sharp turns.The feathers also protect it from sunburn.What Makes an Ostrich a Bird?What Makes an Ostrich a Bird?All birds have a backbone have feathers have wings have a bill lay eggs are warm-bloodedO

15、strich eggs are the largest and thickest of any birds.An ostrich only has two toes on each foot.An ostrich cant fly,but its feathers keep it warm.Its wings help it balance when running.An ostrichs neck makes up almost half of its height.An ostrichs eyes are five times bigger than a humans eyes.An os

16、trichs long neck helps it in multitudes of ways.With this added height,the ostrich can hold its head up high to scout out new places,find food,or spot oncoming danger.Its eyes are the biggest of any animal on land.They measure 2 inches(5 cm)across and are adorned with long,luscious eyelashes.Surpris

17、ingly,everything about an ostrich is supersized except for its head and brain.Its brain is roughly the size of one of its eyes,which is quite diminutive for such a large,powerful creature.You could say that ostriches are a bit bird-brained!Ostriches deliver a powerful kick to defend against enemies.

18、Ostriches:Giant Birds Level X78Ostriches and DinosaursWe know the speedy ostrich is huge and powerful,but where did it come from?Why cant it fly,and how did it get to be so humongous?Nobody really knows the answers to these questions,but there are many theories about the ostrich.A recent theory sugg

19、ests that millions of years ago,early ancestors of the ostrich were much smaller and maintained the ability to fly.Some scientists think that dinosaurs especially liked to eat them.Fortunately for these birds,they could fly away and escape.Once dinosaurs were extinct,the birds had fewer enemies and,

20、therefore,much more time to graze.Over a long period of time,they eventually became the mammoth,flightless birds we are familiar with today.In another recent study,the resemblance of the ostrich to Tyrannosaurus rex caused some scientists to determine that there had to be a connection.The anatomy of

21、 an ostrich leg and a T.rex leg are extremely similarso similar,in fact,that scientists put an ostrich on a treadmill to understand more about the speed of T.rex.Because of this analysis,we know that a physically fit ostrich would definitely outrun a beefy T.rex.Ostriches use half as much energy as

22、humans when they run because their leg tendons(connective tissues)are twice as“springy.”And the Winner Is.Ostriches are among the closest living relatives of T.rex.Ostriches can run an average of 30 to 45 miles per hour(48.372.4 kph)while T.rex was estimated to clock in at approximately 10 to 25 mil

23、es per hour(1640.2 kph).Ostriches:Giant Birds Level X910Ostrich TerritoryOstrich OriginsIn truth,we havent quite figured out where on planet Earth this extraterrestrial-looking bird originated.Fossils of ancient ostrichlike animals have been discovered in China,Europe,and Canada.The study of these f

24、ossils helps us make educated guesses about whether early relatives of ostriches could fly,where they originated,and how they ended up in Africa,but nobody knows for sure.Home,Home,on the PlainsToday,ostriches live in the eastern and southern plains of the African continent.This dry region,where abu

25、ndant scrubby grasses and few trees grow,provides a suitable home for these birds.The savanna is a land of extremes,with temperatures ranging from very hot during the day to quite low at night.The average yearly temperature ranges from 68 to 86F(2030C),with slightly cooler temperatures in winter.Ost

26、riches respond to these extreme temperatures by fanning themselves with their feathers in the daytime to keep cool and covering their legs with their feathers at night when the temperature drops.Ostrich rangeEquatorOstrich rangeWhere Ostriches LiveWhere Ostriches LiveAFRICAEUROPEATLANTIC OCEANATLANT

27、IC OCEANINDIAN OCEANThe Latin name for the ostrich is Struthio camelus,meaning“camel-like.”Camels and ostriches both have long necks and prominent eyes and can go without water for long periods of time.Ostriches live on ranches all over the world but are only native to Africa.AFRICAEUROPEASIAOstrich

28、es:Giant Birds Level X1112Veggies with a Side of StonesOstriches eat just about any kind of vegetation.They are omnivores that spend most of their time grazing on leaves,seeds,fruit,and plant roots.They also enjoy the occasional insect and lizard.Since ostriches are toothless,they need to eat stones

29、 to aid their digestion.An adult ostrich carries about 2.2 pounds(1 kg)of stones in its gizzard(a digestive organ)to help it“chew”its food.These stones,with the help of digestive fluids,grind the food before it passes into the intestinesand what long intestines ostriches have!Ostrich intestines are

30、46 feet(14 m)long,which is about twice as long as human intestines.Ostrich EnemiesOstriches have many enemies in the wild,including lions,cheetahs,leopards,and hyenas.Also,vultures and jackals steal and eat ostrich eggs.Since ostriches have long necks and large eyes,and are extremely alert,they can

31、spot danger from a great distance and escape.When they need to stand their ground and fight,ostriches have a couple of strong defensive moves they rely on.Their powerful,kicking legs and claws can cause serious damage to any animal.In the past,people hunted ostriches for their beautiful plumes.The f

32、eathers were so popular as decoration for hats and dresses that ostriches were in serious danger of extinction.Today,ostrich plumes are not used nearly as much.A male ostrich makes a loud booming sound when it encounters a predator.Ostriches get a lot of water from the plants they eat and can go for

33、 long periods of time without drinking.BOOMOstriches:Giant Birds Level X1314Living LargeOstriches can live separately or in herds of five to fifty or more birds.While they prefer to stay by themselves,ostriches may peacefully hang out and share grasslands near other grazing animals such as zebras an

34、d antelopes.The other animals benefit from the ostrich,which makes loud noises to warn when danger is near.Ostrich herds usually consist of one dominant adult male(the rooster),several females(the hens),and ostrich chicks.The male ostrich courts several females and chooses which ones can and cannot

35、become members of the herd.Once his herd is established,the male ostrich digs a shallow indentation in the groundhis herds nest.The dominant female lays approximately six eggs in the nest.The eggs are the largest of any bird,weighing about 3 pounds each(1.4 kg).This number one hen allows other hens

36、to share the nest,but her eggs are kept safest in the center.Egg-sitting duty is shared,with the dominant male taking the night shift and the dominant female working the day shift.After about forty-two days,an ostrich chick hatches.The ostrich babies are the size of adult chickens and begin to run a

37、lmost immediately after hatching.The male teaches the chicks how to survive in the wilderness.With any luck,an ostrich may live to age fifty or older.Ostrich chicks are close to adult size in just six months.A male displays his feathers during a mating dance.Myth:Ostriches bury their heads in the sa

38、nd when theyre afraid.The truth:They get very low and put their necks close to the ground to hide from predators.Ostriches are no chickensthey will fight if they have to!Ostriches:Giant Birds Level X1516Odd Duck and Scientific WonderOstriches are grand,mysterious birds.They are fast-paced,skilled ru

39、nners that stand up to predators.They have adapted to a hostile and dangerous environment without the ability to fly.For many reasons,scientists continue to be fascinated with this swift and flightless creature.Studies will continue to discover what makes the ostrich unique,and what traits this feat

40、hery mammoth could possibly have shared with the Tyrannosaurus rex millions of years ago.Glossaryadapted(adj.)changed to fit a new or specific situation or environment(p.15)courts(v.)tries to attract a mate(p.13)defensive(adj.)of or relating to an action of protecting oneself from harm or attack(p.1

41、2)dominant(adj.)more important,effective,or powerful than others(p.13)graze(v.)to eat grasses or other plants in a field(p.7)hostile(adj.)very unfriendly(p.15)indentation(n.)a shallow hole or dimple in a surface(p.13)omnivores(n.)animals that eat both plants and animals(p.11)plumes(n.)feathers or a

42、group of feathers on a bird(p.12)prehistoric(adj.)of or relating to the time before recorded or written history(p.4)savanna(n.)a flat grassland with few trees(p.10)torso(n.)the main part of an animals body that does not include arms,legs,or a head(p.5)Ostriches keep pace with many other speedy animals on the plains.Ostriches:Giant Birds Level X