our living world: earth's biomes - volume 2: tundra

Tundra

T R A D I T I O N B O O K S ® , M A P L E P L A I N , M I N N E S O T A

A N E W T R A D I T I O N I N C H I L D R E N ’ S P U B L I S H I N G TM

2volume

OUR LIVING WORLD: EARTH’S BIOMES

Tundra B a r b a r a A .S o m e r v i l l

�

In gratitude to George R. Peterson Sr. for introducing me to the beauty of creation—George R. Peterson Jr., Publisher, Tradition Books®

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ABOUT THE AUTHOR

Barbara A. Somervill is the author

of many books for children. She loves

learning and sees every writing

project as a chance to learn new

information or gain a new under-

standing. Ms. Somervill grew up in

New York State, but has also lived in

Toronto, Canada; Canberra, Australia;

California; and South Carolina. She

currently lives with her husband in

Simpsonville, South Carolina.

�

CONTENT ADVISER

Susan Woodward, Professor of

Geography, Radford University,

Radford, Virginia

�

Table of Contents

�

Table of Contents[ C h a p t e r O n e ]

4 Defining Arctic and Alpine Tundra[ C h a p t e r T w o ]

22 Focus on Key Species[ C h a p t e r T h r e e ]

32 Predators[ C h a p t e r F o u r ]

43 Prey[ C h a p t e r F i v e ]

51 Flora[ C h a p t e r S i x ]

59 Herbivores[ C h a p t e r S e v e n ]

69 A Cycle of Life[ C h a p t e r E i g h t ]

74 The Breeding Season[ C h a p t e r N i n e ]

82 The Human Touch

9 2 [ C h a r t o f S p e c i e s ]

9 3 [ I n d e x ]

� A snow leopard leaps over

snowdrifts in the Himalaya

Mountains. Her thick fur keeps

her warm in winter. Like most

snow leopards, this female

cat lives alone. She is 4 feet

(1.2 meters) long and weighs

80 pounds (36 kilograms),

DefiningArctic andAlpineTundra

1D

efin

ing

Arct

ic a

nd A

lpin

e Tu

ndra

4

[ C h a p t e r O n e ]

about the size of a big dog.

She hunts with skill and cun-

ning. She can bring down

Himalayan tahrs and ibexes

equal to her own weight.

Today, her hunt leads her

into a valley. The leopard

crouches down against the

snow. Her gray-spotted white

fur blends in against snow-

capped rocks.

A herd of Hima-

layan blue sheep

paws the ground

nearby. The leopard

keeps downwind of

the sheep. The

sheep neither hear

nor smell her approach. She

slinks forward, then leaps. The

herd scatters. They bound onto

sheer, rocky cliffs to escape.

5� A snow leopard prowls the alpine tundra of Asia’s Himalaya Mountains.

WORDS TO KNOW . . .

ibexes (EYE-beks-ez) a large

variety of wild goats

tahrs (TARZ) long-haired mem-

bers of the wild Asian goat fam-

ily found only in the Himalayas

?

� A herd of Tibetan blue sheep keeps a watchful eye out for hungry snow leopards.

The leopard’s

search for food has

failed. She’ll try

again, but next time,

a hare becomes the

target. Hares are

easier to catch than

sheep. They also

make a decent meal.

Snow leopards can’t

be choosy about

what they eat. There

is too little prey available high

in the Himalayas of Asia.

Two Types of Tundra

� Tundra comes from the

Lapp word tundar. It means

“treeless plain”—an accurate

description. Only short, stunt-

ed trees survive the rugged

tundra climate. Those trees are

hard to find.

Tundra supports fewer

types of plants and animals

than most other biomes. It

seems like a barren, heartless

land. Yet it is filled with life.

About 1,700 different plants

grow in arctic and subarctic

ecosystems. These include

grasses, sedges, lichens, wild-

flowers, and shrubs. The plant

varieties growing within each

region depend on soil quali-

ty, weather, and water supply.

There are far fewer animal

species than plants. The

number of animals depends

on available food. The ability

to adapt to harsh weather

also limits the variety of

tundra animals.

Tundra exists in two

forms, alpine and Arctic.

Alpine tundra covers

6

WORDS TO KNOW . . .

biomes (BYE-ohmz) large

ecosystems in which the

plants and animals are adapted

to a particular climate or physi-

cal environment

ecosystems (EE-koh-siss-tuhmz)

communities of plants and

animals and their relationships

with the surrounding environ-

ments

?

A tree like this one is a rarity on Siberian tundra. �Most tundra trees hug close to the ground.

[ D e f i n i n g A r c t i c a n d A l p i n e T u n d r a ]

mountain areas above

the tree line. Arctic tundra

occurs within or near

the Arctic Circle. Both

feature cold climates, little

rainfall, and short

growing seasons.

Few humans live

in tundra environ-

ments.


WORDS TO KNOW . . .

tree line (TREE LINE) the maxi-

mum elevation at which trees

will grow

?

Alpine Tundra

� Alpine tundra is found in

Africa, Asia, Europe, South

America, and North America.

Tundra begins at

different altitudes

in every alpine sys-

tem, depending on

where trees stop

growing. It starts above the

tree line. In the Himalaya

Mountains, tundra begins at

about 14,750 feet (4,500 m).

Rocky Mountain tundra to the

north may begin at lower alti-

tudes—about 8,500 feet

(2,700 m). Usually, alpine

tundra starts between 10,000

and 11,000 feet (3,050 and

3,350 m) in altitude.

At high altitudes, tempera-

tures drop and high winds

whip the landscape. High alti-

tudes also have thinner air.

Animals have less oxygen to

breathe. Plants make do with

lower levels of carbon dioxide,

the gas they need to live.

Many animals and plants

cannot adjust to thinner air

or harsh weather.


WORDS TO KNOW . . .

altitudes (AL-ti-toodz) eleva-

tions above sea level

?

All alpine tundra ecosys-

tems endure odd weather

patterns. Summer mornings

might start sunny and warm.

Yet the day could end with a

snowstorm. Sometimes, the

snow falls so thick it creates a

whiteout. People cannot see

more than a few feet in front

of them in a whiteout.

Average alpine tundra

temperatures range from –2°

to 50° Fahrenheit (–19° to 10°

Celsius). Temperatures on

exposed cliffs and rocky land

drop much lower in winter.

Snowfall may be heavy, though

the region is usually dry.

Alpine tundra animals find

ways to cope with the cold.

9� Pikes Peak, Colorado, is one of the most frequently climbed mountains in

North America.

� In winter, alpine tundra can present a rather bleak landscape.

Bears hibernate. This means

that they fill up on food in the

fall and sleep through the worst

winter weather. Wolves and

mountain lions move to forests

at lower altitudes. They must

hunt food through the winter.

Most alpine birds, including

birds of prey, migrate south.

They head for warmer weather.

10


Atlantic Ocean

IndianOcean

PacificOcean

PacificOcean

ArcticOcean

ArcticOcean

ArcticOcean

0˚

15˚N

30˚N

45˚N

60˚N

75˚N

15˚S

30˚S

45˚S

60˚S

0˚15˚W30˚W45˚W60˚W90˚W 75˚W105˚W120˚W135˚W150˚W165˚W 15˚E 30˚E 45˚E 60˚E 90˚E75˚E 105˚E 120˚E 135˚E 150˚E 165˚E

N O R T HA M E R I C A

S O U T HA M E R I C A

A F R I C A

E U R O P E

A S I A

A U S T R A L I A

G R E E N L A N D

Alpine Tundra

N

� Alpine tundra regions of the world

Alpine Tundra around the World

� In Asia, alpine tundra

is found in the Himalaya

Mountains, the Plateau of

Tibet, and on Fuji, the highest

mountain in Japan. The

Himalayas include Mount

Everest and dozens of other

peaks rising more than 20,000

feet (6,100 m).

The Himalayan alpine

tundra provides homes for

several unusual animal species,

including tahrs, yaks, and

snow leopards. Himalayan

alpine shrubs include juniper

and rhododendron. Mosses,

sedges, and lichens also grow

at tundra heights.

European alpine tundra

exists in the Alps (which

stretch through Italy, Switzer-

land, Lichtenstein, Austria,

and France). In most regions

of the Alps, the tree line lies

from about 5,000 to 9,000

feet (1,500 to 2,740 m). The

tree line can lie at different

altitudes on parts of the same

11


0˚

� Pink rhododendrons splatter color acrossthe Kama Valley near Mount Everest.

mountain. Lush meadows

fill high valleys in the Alps.

Clusters of edelweiss sprinkle

white blooms among meadow

grasses. Few large predators

remain in the Alps. Most have

been overhunted or forced out

of the region. Golden eagles

12


� The Swiss Alps are famous for ski resorts and stunning mountain landscapes.

WORLD WILDLIFE FUND IN

THE NEWS

The World Wildlife Fund (WWF) is

returning bears, wolves, wolverines,

and lynx to Europe’s Alps. For many

years, the Alps had no large predators.

The WWF blames this on bad rumors.

People in European communities grew

up on stories of evil wolves and dan-

gerous bears. Europeans believed that

it was good to kill these predators.

So far, the WWF has reintroduced

two predator groups in Europe. Lynx

now live in the Swiss mountains. A

new group of bears prowls the

Austrian Alps.

patrol the skies above alpine

meadows. They hunt for

rodents and small birds.

Loss of predators in a

region such as the Alps de-

stroys nature’s balance. With-

out predators, plant-eater

populations grow out of con-

trol. Deer, for example, pro-

duce young every year. Too

many deer eat too many plants

and damage forests. The Alps

need predators, such as bears

and wolves, to reduce the

number of plant eaters.

Only a few places in

Africa have alpine tundra.

One of these is Mount

Kilimanjaro in Tanzania.

Kilimanjaro’s alpine zones

contain stumpy scrub trees

and giant-sized plants, such

as senecios and lobelias.

13


cover the land. The most

common grass-eating animals

found in the altiplano are

South American relatives of

camels: vicuña, llama, alpaca,

and guanaco.

In North America, alpine

tundra occurs in the northern

Appalachian Mountains and in

the Rocky Mountains. Most

Appalachian mountains lie too

low to have alpine tundra

zones. Tundra is limited to

small patches on the higher

peaks of New England. Mount

Katahdin, Maine, which rises

5,268 feet (1,606 m), supports

tundra lichens, sedges, and

mosses above the treeline.

The Rockies stretch from

Canada to the southwestern

United States. Rocky Mountain

tundra supports bumblebees

14


Crowned eagles and

lammergeiers circle

the air looking for

prey. Elands and

klipspringers,

types of antelopes,

browse on clumps

of tundra grass.

South Amer-

ica’s Andes Moun-

tains spread more

than 4,500 miles

(7,240 kilometers)

down the western

side of South

America. They fea-

ture the altiplano,

which is Spanish for

“high plains.” The

altiplano is alpine

tundra of a slightly

different kind. There are no

trees, but prairielike grasses

READ IT!

The Rocky Mountains by Larry

Bograd (Benchmark Books,

2001) presents a full picture of

the Rockies. The author explains

the different ecosystems found

in the mountain range.

�

WOULD YOU BELIEVE?

The earth’s largest herb grows

in the Andes at 13,000 feet

(3,965 m) above sea level. The

herb is the Puya raimondii.

When the plant is about 100

years old, it flowers for the

first time—then dies. The

puya plant can reach 35 feet

(10.7 m) tall, and the flowers

can have a diameter of up to

8 feet (2.4 m).

!

Strong winds mold snow into drifts on the tundra in Manitoba, Canada. �

and butterflies, grizzly bears,

mountain sheep and mountain

goats, marmots, pikas, and

rosy finches. Each summer,

wildflowers sprinkle alpine

meadows with color. Winters

find the same landscape blan-

keted by several feet of snow.

Arctic Tundra

� Nothing is as bleak as

Arctic tundra in January.

By then, winter has gripped

the land for several months.

Sunlight casts a faint

glow that lasts barely

an hour each day.

Wind whips the land

day and night.

Arctic tundra

ranges from 55° to

70° north latitude.


WORDS TO KNOW . . .

latitude (LAA-tih-tood) the

distance a point is north or

south of the equator; lines

of latitude run parallel to

the equator

?

Tundra lies in Russia, Alaska,

Canada, and Greenland. It is

also found in Iceland, Norway,

and Sweden.

Arctic tundra has two dis-

tinct animal popula-

tions: summer-only

visitors and perma-

nent residents.

Summers see the

arrival of millions of migrat-

ing birds, such as tundra

swans, snow geese, ducks, and

plovers. Migrating birds come

to lay their eggs and raise

their young on the tundra.

Insects breed in huge

swarms. They plague musk

oxen and caribou with con-

stant buzzing and biting.


WOULD YOU BELIEVE?

Refrigerator temperatures run

between 32°F and 40°F (0°C to

4°C ). Freezers range from 0°F

to 10°F (–18°C to –12°C ). Arctic

tundra temperatures can drop

to –60°F (–51°C ). That’s cold!

!

However, the billions of

insects feed millions of nest-

ing birds.

About 1,700 different

kinds of plants live in Arctic

tundra regions. Most are

sedges, mosses, and lichens.

Thick clusters of grasses

sprout up near icy streams.

About 400 types of wild-

flowers huddle close to the

ground. Their short height

protects them from strong

winds and cold temperatures.

Summer plants reproduce

in a hurry. Flowers must

bloom and produce seeds

during the six- to nine-week

growing season. Ever-present

winds and helpful plant eaters

carry the seeds across the

land. Of the millions of seeds

17� This Arctic tundra is located in Greenland.

� Midnight sun makes an eerie appearance over Alaska.

produced, only

a few actually

become plants.

Winter comes

early in the Arctic,

usually by Septem-

ber. Migrating birds

have already fled

south. Bears and Arctic

ground squirrels glut them-

selves with food. Then they

sleep in their dens until

spring. Rodents nestle in

underground holes called

burrows to keep warm.

Insects and their eggs lie

18

� An Arctic fox’s fur turns white in winter. It helps the fox blend in with its surroundingsso that prey cannot see the fox approaching.

WATCH IT!

National Geographic’s White

Wolf [ASIN: 6304475993] allows

viewers an inside look at life in

a wolf pack. Learn about the

trials and challenges of tundra

wolves in their natural habitat.

�

PROFILE: PERMAFROST

Plant roots struggle to find space in the

thin layer of tundra soil. The roots can-

not reach deep into the soil. A solid

layer of permafrost blocks their path.

Permafrost is permanently frozen

rock or soil. Even when summer tem-

peratures climb higher, permafrost

remains below 32°F (0°C). Permafrost

lies under about one-fourth of earth’s

land. Permafrost in the Siberian region

of Russia reaches as deep as 5,250

feet (1,600 m).

Wolves and foxes grow

extra-thick winter coats.

The fur has two layers. The

short fur close to the skin

keeps the animals warm.

Arctic foxes’ white coats blend

with the snow to help them

hide from the prey they

are hunting.

Many rodents live in

underground burrows.

But they can dig only a

short way. Soil deeper than

20

2 or 3 feet (.6 or .9 m) is

frozen solid. Rodents line

their dens with fur or

plants to add warmth.

Insects head under-

ground for the winter,

too. Some insects have a

special chemical in their

blood. The chemical works

like antifreeze in a car. It

allows the insects to survive

intense cold.

When spring approaches

on the Arctic tundra, snow-

drifts melt and icy streams

rush against their banks.

The aurora borealis fills

the sky with dancing lights.

Summer welcomes millions of

butterflies, bees, mosquitoes,

and flies. Vast flocks of tundra

swans, Canada geese, and

ducks feed their hungry

chicks. Life races

against the coming

winter, when sting-

ing cold will again

grip the land.

21


� The aurora borealis lights up Norway’s nightswith nature’s most beautiful light show.

WORDS TO KNOW . . .

aurora borealis (uh-ROR-uh

bor-ee-AL-iss) lights that

appear in the northern sky

near the Arctic; the aurora is

the result of flares on the sun

?

� It is early June. A female

caribou arrives at the spring

birthing grounds. She is one of

thousands that will give birth

this June.

Snow still covers the hill-

sides, but the doe finds a patch

of bare ground. She gives birth

to twins—a rare occasion. Most

caribou births produce only

one calf.

Focus onKey Species

2Fo

cus

on K

ey S

peci

es

22

[ C h a p t e r T w o ]

Within minutes, the twin

calves rise on shaky legs. After

just hours, they walk. By the

next day, they have enough

strength to travel with the

herd. Young caribou must

keep up with the adults.

Wolves and grizzly bears look

for stragglers. Even golden

eagles have been known to

take caribou calves.

The herd’s size offers the

calves some protection. They

are among thousands of calves

born to the George River herd

in Quebec and Labrador,

Canada. The herd numbers

about 500,000 animals and

is one of the three largest

caribou herds in the world.

Predators will not attack

when so many adults surround

23� Caribou calves must be able to move with the herd when they are only a few hours old.

� Caribou herds migrate along the same paths their ancestors used hundreds ofyears ago.

the calves. Caribou antlers

are too dangerous, even for

hungry wolves.

Keystone Species of the Arctic

� Caribou, or wild rein-

deer, are keystone species of

the Arctic tundra. They play

a major role in the tundra

biome. Without caribou,

many other animals would

not survive.

Wolves and bears hunt

young, old, and injured cari-

bou. Predators must eat to

live. Caribou provide their

food. Predators also keep the

herd healthy by weeding out

weak animals.

Two other predators

attack caribou—mosquitoes

and flies. As many as 2,000

� A male caribou sports huge antlers thatbecome serious weapons in a fight.

flies have been counted

on one buck. Flies and

mosquitoes suck blood. It

is their food.

Once wolves or bears

eat their fill, the dead cari-

bou’s carcass supports other

animals. Blowflies lay live

larvae on dead flesh.

Carrion feeders, such as

gulls, jaegers, and Arctic

foxes, pick at the remaining

meat. No part of a dead cari-

bou goes unused. Even dis-

carded antlers provide food

for porcupines.

As caribou travel, they

deposit feces along their

paths. This waste carries

seeds and spores of plants

the caribou ate. The caribou

help spread plant life across

the tundra.

Keystone Speciesin Alpine Tundra

� A keystone

species in alpine

tundra is the pika.

Pikas belong to the

rabbit family. They

live in the Himala-

yas, the Rockies,

and in most alpine

locations. Pikas pro-

vide wolves with

about half their food

supply. Snow leop-

ards, brown bears,

steppe eagles, and

goshawks also

stalk pikas.

Pika burrows

provide homes for

small birds, such as

ground jays and

25

[ F o c u s o n K e y S p e c i e s ]

WORDS TO KNOW . . .

carcass (KAR-kuhss) the body

of a dead animal

carrion (CAH-ree-uhn) dead or

rotting flesh

feces (FEE-seez) solid waste of

an animal or human

larvae (LAR-vee) insects at the

stage of development between

eggs and pupae when they

look like worms

?

LOOK IT UP!

Caribou travel 800 miles (1,290

km) a year through an incredi-

bly demanding ecosystem.

Learn more about caribou at

these Web sites: http://www.

environmentyukon.gov.yk.ca/

fishwild/caribou.shtml and

http://idahoes.fws.gov/Fact/

Caribou.html.

�

snowfinches. Lizards like

pika burrows, as well. These

animals don’t bother pikas.

The pika’s sharp claws

scratch away soil. This action

keeps soil fresh and increases

plant growth. Pikas eat

plants. They collect and

store leaves and grasses

in small haystacks. Like

caribou waste, pika waste

spreads plant seeds through

the ecosystem.

Pocket gophers are a key-

stone species of the Rocky

Mountain alpine tundra.

They provide the same serv-

ices to an alpine biome as

Asian pikas. They dig bur-

rows almost continuously.

Pocket gophers turn soil and

spread seeds through feces.

Like squirrels and mice,

gophers are rodents. They’re

not much of a meal, but hun-

gry predators do eat them.

26

� The pika is a favorite food of manytundra predators.

A grizzly bear mother must teach her cubs how to find edible berries, nuts, and roots �in the tundra.

Umbrella Species

� Governments pass laws

to protect endangered or

threatened species. Legal

protection may outlaw hunt-

ing an animal or digging up

a plant. It may limit roads

that run through a territory.

Laws may punish people for

killing endangered animals.

An umbrella species is

a protected animal or plant

that spreads its legal protec-

tion over other

creatures. For

example, a grizzly

bear’s home area

ranges from 70 to

400 square miles

(181 to 1,036 sq

km). Protecting a

grizzly bear from hunting or

loss of habitat covers its

entire range. Many other ani-

mals and plants live within

that territory. When the

bear’s territory is protected,


WORDS TO KNOW . . .

endangered (en-DAYN-jurd) on

the edge being completely

wiped out; few members of a

species still surviving

threatened (THRET-uhnd) at

risk of becoming endangered

?


umbrella species. So do

wolves and caribou. Bears and

wolves roam large territories.

Laws protect these predators.

That protection spreads out

like an umbrella over the

tundra biome.

Flagship Species

� Flagship species star in

television specials. They have

those plants and

animals share in

that protection.

Grizzly bears

are not the only

umbrella species of

the tundra. Other

tundra bears, such

as Asiatic black

bears and polar

bears, also serve as

READ IT!

Discover everything you need to

know about grizzly bears. Read

Grizzly Bear by Alvin and

Virginia Silverstein (Millbrook

Press, 1998).

��

WOULD YOU BELIEVE?

Most bears are omnivores. That

means they eat both meat and

plants. A hungry grizzly can get

into a feeding frenzy. It may eat

200,000 berries in one day!

!

Web sites dedicated to them.

They create interest, emotion,

and money. In the tundra,

flagship species include

wolves, polar bears, lynx,

and grizzly bears.

Saving a flagship species

interests people in several

ways. People form organiza-

tions to save polar bears and

caribou. They “adopt” wolves

that live in protected habitats.

Governments pass laws to

protect these popular species.

Flagship species help

preserve an ecosystem. Like

an umbrella species, their

protection spreads over a

region. Their problems

become “news.” The more

people who understand issues

facing an ecosystem, the

more likely those problems

will end.

29� A polar bear and her cub hunt ring seals on the pack ice in Manitoba. They find the

seal by scent and then pounce a hole in the ice to catch their prey.

� A lone male wolf crosses open ground. He will live alone until he finds a mate, andthe pair will then start a pack of their own.

Indicator Species

� An indicator species mea-

sures the overall health of an

ecosystem. Scientists believe

that polar bears are an indica-

tor species of the Arctic tun-

dra. Polar bears live on land

but hunt and travel in the seas.

They pursue ringed seals by

walking out on solid ocean

ice. They find the seals living

under the ice.

Scientists see a trend

toward smaller, thinner, hun-

grier polar bears. They believe

this trend results from warmer

earth temperatures. Warmer

seas mean that solid ice forms

later. Polar bears cannot hunt

seals until solid ice forms. Less

ice means shorter hunting sea-

sons for polar bears. The thin-

ner bears are showing scien-

tists how warmer earth temper-

atures affect the tundra.

Plants make excellent

indicator species for both

Arctic and alpine tundra.

Some lichens and sedges will

grow only under certain condi-

tions. They need the right

amount of water and sunlight,

and a specific environment to

grow. These plants react to

reduced or excess rainfall or

snowfall. They do not grow

in polluted environments.

Less plant growth shows

problems in an ecosystem.

Most tundra plant eaters sur-

vive on sedges and lichens.

If ecosystem problems are

not fixed, the plants will not

grow. Animal species that

eat the plants will suffer.

31


� Lichens cling to tundra rocks like rust to an old car.

� Tundra life spins in an

ever-widening cycle. Five extra

warm days in Siberia, Russia,

lengthen the growing season

one year. Plentiful grasses and

wildflowers fatten voles and

lemmings. In turn, these

plump rodent mothers give

Predators3 [ C h a p t e r T h r e e ]

birth to larger, healthier

babies.

A breeding pair of snowy

owls protects its nest in a hol-

low. This year, the female laid

seven eggs. All hatched into

healthy, squawking owlets.

Seven hungry owlets demand

constant food. Luckily, the

healthy vole and lemming

populations provide food for

Pred

ator

s

32

PROFILE: GYRFALCONS

Gyrfalcons are the largest falcons. These

aggressive hunters may be white, light

gray, or brown-gray in color. They live

along rocky Arctic coasts, but they catch

their prey on open tundra. Gyrfalcons

hunt gulls, snow geese, ptarmigans,

and ducks.

Today, 1,650 to 2,650 breeding pairs

of gyrfalcons live in northern Europe.

Laws protect gyrfalcons in the wild.

However, poachers, or illegal hunters,

still capture and sell the birds. Live adult

gyrfalcons are sold illegally at prices

ranging from $10,000 to $100,000.

the owl family. Without

Siberia’s five extra warm days,

it would normally take a

breeding pair of snowy owls

two years to produce and raise

seven healthy fledgling owlets.

Snowy owls are birds of

prey. They eat animals. Unlike

most other owls, snowy owls

hunt in daylight. Successful

hunts at dawn and dusk feed

hungry mouths.

The owlets grow quickly.

By early fall, they have a full

set of feathers and can hunt

for themselves. Mild weather

and plentiful food allow snowy

owls to stay on the tundra all

winter. This year’s success

came from five extra warm

days.

Other birds of prey

also live in alpine and Arctic

33

[ P r e d a t o r s ]

� Snowy owls find plenty to eat in thetundra, including lemmings, groundsquirrels, mice, and hares.

tundra. Hawks, eagles, fal-

cons, jaegers, and merlins fare

well in the tundra ecosystem.

There are plenty of small

rodents and birds for them

to eat.

Food Supply

� The success of a predator

species depends on what the

animal eats. Predators that eat

a variety of foods have a better

chance of survival. Snowy owls

prefer voles and lemmings,

but also eat ducks, ptarmi-

gans, hares, and geese. Bears

fish for salmon in icy tundra

rivers but will eat berries,

nuts, flower bulbs, insects,

rodents, and lizards.

34

� A bald eagle fishes for salmon in an icy Alaskan river.

Some predators hunt for

food but will also eat carrion

if they find it. Foxes and

wolverines dine on the left-

overs of other predators.

Polar bears hunt ringed seals,

but they eat only the blubber.

An Arctic fox happily eats the

remaining meat.

Eating rotting meat seems

disgusting. However, nature

does not waste food. Every

part of a carcass feeds some-

thing, whether it is fly larvae,

foxes, or voles that gnaw on

bones.

Top of the Food Chain

� At the top of the food

chain are large predators.

Other than humans, large

predators have few enemies.

The tundra provides enough

food for large cats, bears,

wolves, and foxes.

Big cats from

alpine tundra

regions include

snow leopards,

mountain lions, and

lynx. Big cats hunt

by stealth. They

sneak up on their

prey. When in

range, they leap on

35


� A wolverine digs a storage pantry for itsleftovers. If today’s hunt fails, it will eatlast week’s caribou.

WOULD YOU BELIEVE?

Most predators kill only what

they can eat right then. This is

not true of wolverines. They

hunt with future meals in mind.

Wolverines store extra meat

underground. When prey is

scarce, they choose a meal from

their underground “freezer.”

!

their targets. Big

cats use lightning

quickness to catch

prey. Sharp claws

and powerful teeth

bring the prey to

the ground.

Cougars, also called

mountain lions or pumas, live

in many different biomes.

They are the largest preda-

tors in the Andes alpine

tundra. In North America,

cougars roam the Rocky

Mountains. Cougars eat

rodents, but they prefer wild

sheep or deer.

The smallest tundra

“big” cat is the lynx. Lynx

weigh between 15 and 25

pounds (7 and 11 kg). At one

time, lynx lived in 21 of the

lower 48 states. Today, fewer

than one thousand lynx live

in only four states: Washing-

ton, Montana, Colorado, and

Maine. Other types of lynx

exist in Siberia, Spain,

Europe, and Central Asia.

Lynx do well in both Arctic

36

� A cougar takes a refreshing dip in an alpinetundra pool. Cougars, unlike house cats, donot mind a dip in a spring.

WOULD YOU BELIEVE?

Cougars can spring 18 feet

(5.5 m) from the ground to a

cliff. Along the ground, they

can cover 40 feet (12 m) in

one long jump.

!

and alpine tundra ecosys-

tems. They eat mostly

hares, rabbits, and rodents.

Bears, Wolves, and Foxes

� Bears come in large, larg-

er, and largest. Polar bears are

the biggest land carnivores.

Males average 1,200 pounds

(544 kg), and females are

about half that weight. Polar

bears hunt ringed seals and

bearded seals by smell. They

pound on the ice

above a seal’s home

to break the ice.

Polar bears do not

drink water. They

get water from seal

blubber. At times,

37


� This lynx is at full stretch as it prepares to pounce on its prey.

LOOK IT UP!

Learn more about lynx around

the world. Access lynx links

at http://lynx.uio.no/jon/lynx/.

��

WORDS TO KNOW . . .

carnivores (KAR-nuh-vorz)

animals that eat meat

?

polar bears also eat

young walruses,

grass, seaweed, and

carrion.

Himalayan, or

Tibetan, black bears are tiny

compared to polar bears.

Adult males usually weigh less

than 400 pounds (181 kg).

Females weigh from 110 to

275 pounds (50 to 125 kg).

Himalayan black bears are

omnivores. They eat fruit,

bees’ nests, insects, rodents,

and carrion. They travel

across alpine tundra only dur-

ing the summer. Then berries

are plentiful, and bees’ nests

are filled with honey. In win-

ter months, they live at lower

altitudes.

Brown bears live in North

America, Europe, and Asia.

Grizzlies are brown bears.

In the Arctic, male brown

bears weigh between 500 and

1,320 pounds (227 and 600

kg). In alpine regions, brown

38

WORDS TO KNOW . . .

omnivores (OM-nuh-vorz)

animals that eat both plants

and meat

?

� Himalayan black bears are a rare sight.These shy bears live well away fromtowns and villages in Tibet and Nepal.

These grizzly cubs must learn how to fish for salmon. Grizzlies glut on salmon to �

add body fat for a long Arctic winter’s sleep.

bears weigh about 200 pounds

(91 kg) less.

Grizzlies fishing for

salmon are popular images

on tourist posters. However,

most grizzlies eat the carrion

of moose, elk, deer, or cari-

bou. They will also hunt the

young of those species.

Wolves live and hunt in

groups called packs. Wolves

inhabit both types of tundra.

The pack moves toward a

herd of prey. They single out


young, injured, or very old

animals to attack. Wolves

may also hunt alone when

the prey is small, such as

hares, marmots, or voles.

Arctic foxes spend sum-

mer months alone, but they

collect in packs during the

winter. They hunt small

mammals, such as

hares and lem-

mings. Arctic foxes

also eat dead fish

and carrion. They

often eat leftovers after bears

finish with a carcass.

Bloodsuckers

� The hungriest and

peskiest tundra predators

are swarms of insects. They

make a serious impact on

the ecosystem during their

summer-only lives. Midges,

flies, and mosquitoes attack

wild animals and humans

alike. Some tundra insects,

such as wasps and dragon-

flies, prey on other insects.

At one level, insects are

fierce predators. At another

level, they are primary prey

for birds and rodents. Many

wading birds and songbirds

are insectivores.

Among horseflies and

mosquitoes, only the females

suck blood. Males drink

plant juices or eat pollen.

Mosquitoes and flies have

sharp mouths that cut easily

through animal hides. In the

Arctic, flies and mosquitoes

plague caribou.

Many flies and beetles

eat carrion. They get rid of

40


WORDS TO KNOW . . .

insectivores (in-SEKT-uh-vorz)

animals that eat insects

?

41


� While this scene seems brutal, wolf packs actually keep deer populations healthy.They fell old, sick, or weak deer from the herd.

rotting carcasses, dung (ani-

mal feces), and other animal

waste from the tundra.

Blowflies, for example, lay

their eggs on carrion. The

young, called maggots, eat

rotting flesh until they

become adult flies.

42

� Mosquitoes swarm around this moose, caught taking a dip to get rid of thepesky insects.

� A small colony of

hoary marmots munches

on grasses in an alpine

meadow. The colony male

heads the group. He stands

on a boulder overlooking

the meadow. The other mar-

mots do not go far. Their

main protection from

[ C h a p t e r F o u r ] 4Prey

43

Prey

� Marmots, like pikas, are important members of the tundra community. They providefood for prey and distribute plant seeds.

WORDS TO KNOW . . .

colony male (KOL-uh-nee

MALE) the head or leading

male of a group of marmots

?

predators is a quick exit into

their burrow.

Marmots live where

alpine meadows provide food

and rocky slopes offer protec-

tion. Where food is plentiful,

marmots live in colonies of

a dozen or so animals. If

food is scarce, they live in

small families that consist

of a male, female, and recent

young. Marmots hibernate

during the winter. They begin

sleeping in September or

44

� Hoary marmots in Denali National Park, Alaska, form part of the complex cycle of lifein tundra environments.

October and emerge from

their dens in early May.

Overhead, a golden eagle

circles. The colony male spots

the eagle. He lets out a shrill

whistle. Suddenly, the other

marmots stop eating and dash

for the burrow. They know by

the male’s call that the preda-

tor is a golden eagle. Each call

identifies a different enemy.

The colony male takes

his watchdog role seriously.

He shrieks when any other

animal comes near, even if

there is no danger. For mar-

mots, danger comes from

eagles, coyotes, lynx, bears,

and wolverines.

Limited Fare

� Neither alpine nor Arctic

tundra offers much variety in

prey. Most birds and insects are

summer residents. That leaves

the few birds that live perma-

nently on the tundra—along

with rodents, hares, and pikas—

as prey.

Ptarmigans live comfort-

ably in tundra ecosystems all

year. Their feathers

change color with

the seasons. Winter

white coloring

makes them nearly

invisible against the

snow. In the sum-

mer, they are speck-

led brown. If they don’t move,

they can’t be seen. Camou-

flage is the ptarmigan’s only

protection from predators.

Rodents make up the

largest year-round prey group.

Rodents range from small

45

[ P r e y ]

WORDS TO KNOW . . .

camouflage (KAM-uh-flahzh)

coloring that blends in with

the surroundings

ptarmigans (TAHR-mih-ganz)

game birds similar to grouse

?

voles to large muskrats and

porcupines. Most rodents dig

burrows with several entries,

rooms, and escape hatches.

Arctic ground squirrels such

as marmots live in colonies.

Their burrows may have as

many as 50 tunnels and

dozens of rooms.

Lemmings are tundra

rodents that produce many

young. A female has her first

litter in March. From then on,

she produces five or six more

46

� An Arctic ground squirrel will pass the tundra winter in a warm, underground burrow.

litters before the next winter.

An average litter has four to

eight young. Before female

lemmings are a month old,

they can produce litters.

Within one summer, a male

lemming may be a father,

grandfather, and great grand-

father—several times over!

Most tundra predators eat

lemmings. Because lemmings

usually weigh only about 2

ounces (57 grams), it takes

several lemmings to make a

meal. An adult snowy owl eats

a dozen lemmings a day.

Snowshoe hares, Arctic

hares, and pikas are slightly

larger prey. Hawks, foxes, lynx,

wolves, and coyotes all hunt

hares. Hares evade predators

by running, hopping, and

ducking down their holes.

Snowshoe hares run 27 miles

(43 km) per hour in short

bursts. They can cover 10

feet (3 m) in one jump. Like

Arctic foxes, snowshoe hares

wear white coats in winter

and brown for the

summer. Their col-

oring helps the

hares “hide” on

open ground.

47

[ P r e y ]

� A snowshoe rabbit’s white coat blends in withthe surrounding snow. A quick getaway savesthis bunny from becoming breakfast.

WOULD YOU BELIEVE?

A pair of lemmings and three

generations with six females per

litter may produce as many as

4,000 young in one year.

!

A SummerBuffet

� Few predators

willingly face an

angry mother swan

or goose. They’ll get

honks, hisses, and serious nips

for their trouble. However, eggs

or hatchlings are a different

story. Weasels and mink are

nest thieves. They steal eggs

and young birds while parent

birds are away hunting for food.

48

� An elegant tundra swan stretches its wings on a Canadian tundra pond.

WATCH IT!

Living Planet: The Frozen Earth

with David Attenborough

(BBC/Time Life Videos, 2001)

takes viewers from the peaks

of the Andes to the Arctic.

The video explains how plants

and animals can survive such

extreme weather conditions.

�

Weasels and mink have

plenty of company in hunting

young birds. Birds of prey

often hunt chicks and song-

birds for food. The Arctic pere-

grine falcon plucks songbirds

out of the sky. Falcons can fly

at speeds of 60 miles (97 km)

per hour. They dive at speeds

of 230 miles (370 km) per

hour. Few songbirds can escape

a hunting peregrine falcon.

A type of jaeger lets other

birds do its hunting. When

another bird of prey has

caught a meal, the jaeger

49

[ P r e y ]

� Can you find the two eggs that belong to these long-tailed jaegers? They arethe same color as the ground, which protects them from predators.

grabs it from him in midair

and eats it. Jaegers are not

the only feathered food

thieves. Pushy gulls and

skuas regularly rob prey

from shy puffins and

skittish kittiwakes.

Billions of insects buzz,

click, and hum through the

tundra summer. Insects pro-

vide food as eggs, larvae, and

adults. Jaegers, plovers,

buntings, and snow geese

feed on insects.

The role of prey seems

brutal. Prey produce thou-

sands, millions, perhaps

billions of young, only to

have their offspring eaten.

The number of prey avail-

able limits the number of

predators in an ecosystem.

Less prey equals fewer

predators. On the other

hand, predators keep

prey populations from

exploding. Without this

natural balance, the tundra

would be knee-high in lem-

mings or grasshoppers.

50

� Black-backed gulls hover near a cliff, readyto steal fish from shy puffins.

� A caribou bends to

browse on low-lying lichens.

The lichens cover a rock the

size of a dinner plate. One

type of lichen that caribou

find delicious is called rein-

deer moss. It is one of nearly

2,500 different varieties of

lichen that grow in the Arctic.

Lichens have no roots and

grow very slowly.

[ C h a p t e r F i v e ] 5Flora

� Male caribou move through tussocks of tundra grasses on their annual migration.

Flora

51

Lichens are

neither alga nor

fungus, but are

instead a strange

combination of

both plant species.

Alga, the green

slime found on

ponds, produces

food for lichens.

The fungus, related

to mushrooms, gives lichens

strength. Lichen colors range

from orange-brown to gray-

green to off-white.

Plants of the ArcticTundra

� Arctic tundra plants face

serious challenges. Some-

times, there are fewer than

six or seven weeks in a grow-

[ F l o r a ]

READ IT!

Arctic Tundra and Polar Deserts

by Chris Woodford (Raintree/

Steck Vaughn, 2002) presents

a thorough picture of the dry,

barren tundra region.

��

WORDS TO KNOW . . .

alga (AL-juh) a simple one-

celled plant

fungus (FUHN-guhss) a flower-

less, leafless type of plant

?

ing period. Soil is shallow

and poor. Tundra climate

will not support many types

of plants. There is too much

cold and wind, and too little

rainfall for most plants.

Almost all Arctic tundra

plants grow close to the

ground. Their low height

protects them from bitter

winds. It also allows snow

cover to protect the plants

during winter. Dwarf willows

grow wide rather than tall.

They may reach only 4 inches

(10 centimeters) tall, but their

branches spread 15 feet (4.6

m) along the ground. The wil-

low’s roots stretch out an equal

distance underground.

53� Low-lying tundra plants hug the ground near this pond.

� Stunning saxifrage must bloom and produce seeds during the short Arctic summer.

Leaf color and shape are

key factors in plant survival.

Many Arctic plants have dark

green, red, or purple leaves.

Dark leaves absorb

heat and light bet-

ter than pale green

or yellow leaves.

Leaves tend to be

thick and grow

54

close together on many Arctic

plants. Saxifrage, for example,

traps a cushion of air within

its leaves and stems. The dif-

ference between the air tem-

perature outside and the tem-

perature inside the cushion

may be as great as 27°F (12°C).

Leaves may also be leath-

ery or hairy. Leathery saxifrage

leaves retain water. The Arctic

climate is very dry. Holding

water inside the plant may

mean the difference between

living and dying.

Wildflowers paint the

tundra with color during the

short, sunlit summer. Yellow

Arctic poppies and butter-

cups, vivid blue lupines, and

rich, purplish red fireweed

brighten the bare landscape.

Wildflowers are perennials

� Arctic wildflowers cling to soil caught betweenrocks. They paint the landscape with yellows,reds, and pinks.

WORDS TO KNOW . . .

perennials (puh-REN-ee-uhlz)

plants that have lifespans of

longer than two years

?

with many small blooms. They

produce seeds by the millions.

The seeds are carried by birds

and insects or by the wind.

Bearberry, crowberry, and

nagoonberry shrubs sprout

near streams and ponds. Their

fruit feeds birds, bears, and

hares. Animals spread berry

seeds in their feces.

The most common tun-

dra plants are moss-

es, sedges, and

lichens. All three

grow close to the

ground. Spongy,

green moss grows

in wet areas, such

as bogs or marshes.

Sedges look like

wild grass. They grow in thick

clumps, which protect fragile

55

� Bears go wild for delicious cloudberries. They can eat thousands in oneday’s feeding frenzy.

DO IT!

Plant a tundra garden. If you

live where snow falls, tundra

wildflowers should grow in

your local soil. Most seed

catalogs have sections of

wildflower seeds. Next spring,

you could have Arctic poppies,

lupines, or fireweed growing

right outside your door.

��

roots from the cold. Lichens

grow extremely slowly, but

there are plenty of them.

Lichens can be crusty or

leafy. Caribou and musk oxen

feed on sedges and lichens.

Plants of the Alpine Tundra

� Alpine tundra plants adapt

to cold and wind much like

Arctic tundra plants. They

grow close to the ground with

wide-spreading roots. They

often have dark green, red,

or purple leaves to absorb heat

and sun. Hairy, leathery, and

woolly plants are found in

many alpine regions. As in the

Arctic, wildflowers sprinkle

alpine meadows with yellows,

pinks, and purples.

Alpine plants range from

gnarly, dwarfed trees to bril-

liant wildflowers and dusty

lichens. Like Arctic plants,

alpine flora faces challenging

conditions. Surprisingly, there

are far more Arctic tundra

plants than alpine plants. The

Colorado alpine tundra sup-

ports just more than 300 types

of plants. Alaskan Arctic tundra

supports 1,400 plant varieties.

A region of stunted,

dwarf trees often lies above

the tree line. This region is

called krummholz, which is

German for “crooked wood.”

Krummholz trees endure

strong winds and bleak

weather conditions. The wind

and weather twist and bend

the trees until they look like

hunched-over skeletons.

Meadows lie in many

56

[ F l o r a ]

alpine tundra valleys. The

meadows have lush growths

of grasses, shrubs, and wild-

flowers. Rhododendron, an

evergreen with clusters of

pink, yellow, or white flowers,

is a common alpine shrub. It

grows in Sweden, Norway, the

Himalayas, and parts of North

America. The European

Alps are home to soft pink

alpen-roses and pure white

edelweiss. Africa’s Mount

Kilimanjaro has supersized

wildflowers—giant senecio and

giant lobelia.

North America’s Rocky

Mountains have spectacular

57

� Wind, cold, and dryness stunt the growth of tundra trees. These trees are calledkrummholz, which is German for “crooked wood.”

meadows. Yellow buttercups

and dandelions, blue lupines,

and bright pink shooting stars

dance among tall grasses. In

late summer, ripe bilberries,

blueberries, and thimbleber-

ries weigh down branches.

Most alpine tundra has

grasses, sedges, mosses, and

lichens. The grasses grow in

meadows and in clusters

called tussocks. Grasslike

sedges feature tiny green,

brown, or blackish flowers.

Mosses carpet stream banks

and grow up tree trunks.

And lichens, as in the Arctic,

grip tightly to rocks. While

not as beautiful as wildflow-

ers, these plants provide

food for alpine plant eaters

throughout the year.

58

� Ripe Alaskan blueberries dangle from a branch.

� A bitter wind sweeps

across the Andes Mountains

of South America. On a high

plateau, a herd of vicuñas

browses on stunted grasses.

Vicuñas look like camels with

no humps.

This region is the puna—

Andes plains found at about

13,000 feet (4,000 m) above

sea level. There is little

oxygen at this height.

Vicuñas have adapted to

survive in these conditions.

Their extra-large hearts

and lungs distribute oxygen

to their blood.

6H

erbivores[ C h a p t e r S i x ]

Herbivores

� These camel-like creatures are vicuñas. They live in the high plains of the Andes.

59

Vicuñas move in small

herds with a male leader, sever-

al females, and young. The

herd feeds on grasses and

low-lying plants. Vicuñas

have sharp front teeth, used

to rip tough grass from its

roots. Their top front teeth

wear down, but their bottom

front teeth continue to grow.

From Guanacos to Grasshoppers

� Herbivores eat plants.

The term comes from the

Latin words herb (“plant”)

and vore (“eater”). Tundra

plant eaters usually munch

on any plants they can

find. There is not enough

60

� Vicuñas graze on sedges in the Andes tundra.

This Dall ram has quite a rack of horns. Despite its size, Dall sheep are agile climbers �on alpine slopes.

plant life for herbivores to be

fussy eaters.

Large herbivores roam

both alpine and Arctic ecosys-

tems. Most are types of cattle,

sheep, goats, or camels. Alpine

plant eaters often have cleft

hooves. That means their

hooves are split in the middle.

Split hooves help the animals

climb rocky cliffs and moun-

tains. Regardless of their size,

cleft-hooved animals walk easi-

ly on the narrowest paths. This

feature helps them avoid preda-

tors, such as cougars, wolves,

or bears.

Musk oxen and caribou are

the Arctic’s biggest herbivores.

Caribou travel in vast herds

along routes carved by their

ancestors hundreds of years

[ H e r b i v o r e s ]

ago. Caribou browse

on sedges and lich-

ens. Their favorite

meal is reindeer

moss, which is

actually a form of lichen.

Musk oxen physically

resemble small bison. They are

broad chested and have long

hair. They prefer eating grass

but will graze on most plants.

Musk oxen were once plentiful

in the Arctic. Their herds

nearly fell to extinction in

North America. In 1930, the

United States Fish and Wildlife

Service bought 34 musk oxen

from Greenland. These beasts

formed a core herd and lived

on Nunivak Island, Alaska.

By 1980, the musk oxen had

divided themselves into three

separate herds. Their popula-

tion reached 400 animals.

Today, musk oxen live in

Alaska, Canada, Greenland,

and Siberia. They thrive

because their herds have legal


� Musk oxen nearly became extinct, butcurrent conservation programs aresaving this hairy Arctic dweller.

WORDS TO KNOW . . .

extinction (ek-STINGKT-shuhn)

the state of having no more liv-

ing members of a species

?

PROFILE: YAKS

Shaggy, scruffy yaks live high on the

Plateau of Tibet in Asia. They have

short, thick bodies and even shorter

legs. Their bodies are shaped to with-

stand brutal winters at altitudes up to

20,000 feet (6,100 m). Split hooves give

yaks traction on steep, icy ground. They

are surprisingly graceful when climbing

rocky cliffs.

About 3,000 years ago, Tibetans

caught yaks and tamed them. They

started herds of domesticated, or

tamed, yaks. The herds provided meat

and skins for clothing. People milked

yak cows and made cheese and butter.

Domestic yaks are as different from

wild yaks as pet dogs are from wolves.

Humans have overhunted wild yaks

and have taken away their natural

habitats. Fewer than 500 wild yaks

remain. Although laws protect yaks

from hunters, poachers still kill them.

protection from hunters.

Alpine tundra herbivores

differ by location. The Himala-

yas have yaks, blue sheep, and

ibex. Alpine ibex and chamois

live in Europe’s Alps. The

Andes provide homes for

vicuñas and guanacos. Rocky

Mountain tundra has Dall

sheep, bighorn sheep, and

mountain goats.

63


DO IT!

Your family, scout troop, or class

can adopt a musk ox calf from

The Musk Ox Farm in Palmer,

Alaska. The calves live on the

farm and are raised by volun-

teers. Visit the Musk Ox Farm

Web site (http://www.musk

oxfarm.org) to find out about

adopting a musk ox.

�

64


� A delicate rosy finch provides a sweet song amid the tundra’s summer wildflowers.

Smaller herbivores on the

tundra include birds, rodents,

rabbits and hares, and insects.

These animals eat whatever

they find: grasses, flowers,

mosses, lichens, sedges, and

seeds. Many store dried grass

and seeds for the long winter.

Tundra songbirds have

names as lovely as their songs:

rosy finches, white-crowned

sparrows, and snow buntings.

Songbirds prefer seeds and

plants but also eat insects.

Most songbirds migrate south

before snow falls.

Rabbits, hares, and pikas

belong to the lagomorph fami-

ly. Snowshoe and Arctic hares

eat grasses during the summer.

In winter months, they chew

on twigs, buds, or bark. Pikas

prefer to store food. They col-

lect leaves, grass,

and seeds through-

out the summer.

They dry plant

matter in cracks

between rocks.

Pikas eat heartily

all winter long.

Rodents make

up much of the

mammal population

on the tundra. Lem-

mings, ground

squirrels, and voles

dig passages

through the shallow

Arctic soil. Their

relatives—pocket

gophers—do the

same in alpine

meadows. Pocket

gophers stuff their

cheeks with roots

65


WORDS TO KNOW . . .

lagomorph (LAHG-uh-morf) a

mammal that gnaws plant food

?

WOULD YOU BELIEVE?

Arctic ground squirrels sleep

through seven months of tun-

dra winter. During warm

months, they gorge themselves

on seeds, leaves, flowers,

berries, roots, and mushrooms.

Arctic ground squirrels collect

food nearly 18 hours a day.

They usually eat at around

lunchtime. The squirrels need a

thick layer of fat on their bod-

ies by August if they are to sur-

vive hibernation. Many ground

squirrels do not survive. Some

die because they did not have

enough body fat. Others are

uncovered and eaten by bears.

!

and scurry into their burrows

to eat. Voles are not as partic-

ular. They eat grass, leaves,

bark, or seeds.

Individual insects do not

eat much food. However,

there are so many insects that

tons of plants wind up being

devoured. Grasshoppers, may-

flies, and several types of bee-

tles feast on grasses and

leaves. Rotting plant matter

feeds some insects. Others

prefer young sprouts, bloom-

ing flowers, or plant liquids.

Some flies lay eggs on rotting

wood or plant matter. Just as

with animal carcasses, no

usable plant matter goes to

waste. Plants are also used to

build nests.

Butterflies and moths

deposit their eggs on leaves

or plant stems. The eggs grow

66

� Even the coldest, bleakest habitat has it share of hairy, crawling creatures, like thiscommon tundra insect called a springtail.

A sulfur butterfly lands on a curled tendril from a low-lying vine. �

into caterpillars. The cater-

pillars eat the plant until they

spin cocoons. Weeks later,

butterflies or moths emerge

from the cocoons. The cycle

begins again.

Bees drink nectar. They

fulfill an important job on the

tundra. They carry pollen

from one flower to another.

The delivered pollen fertilizes

wildflowers. Without pollen,

plants could not produce

fruit or seeds. Without bees,

wildflowers might not grow

in the tundra.


Herbivores play an

important role in tundra

ecosystems. They eat seeds

and spread them across the

land through their feces.

They clear rotting plants and

allow new plants to grow.

They carry pollen from plant

to plant. Herbivores also pro-

vide predators with prey.

This, too, is part of life on

the tundra.

68

� The bobcat seems to be winning the race against this snowshoe hare.

� Tundra wolves are top

predators. In a pack, they can

bring down a caribou with

[ C h a p t e r S e v e n ] 7A Cycle of Life

� Hunting must be good for this lone wolf. Its coat is thick and its body is well formed.

ease. On their own, they must

find smaller and easier prey.

A three-year-old male

tundra wolf travels alone. He

left his pack nearly one year

ago in search of a mate. It

is September. Soft snow fills

the skies. The wolf’s coat

A Cycle of Life

69

thickens. He needs the extra

warmth for the long winter

ahead. The male settles for

a meal of lemmings. He

weighs nearly 125 pounds

(57 kg), which is large even

for a male. Lemmings pro-

vide little food, and the wolf

hunts daily.

As the male wolf trots

over a ridge, he spies two

adult wolves and three pups

drinking at a nearly frozen

stream. He approaches with

[ A C y c l e o f L i f e ]

care. Male pack leaders do

not welcome strange males.

Both adult wolves are

female! They whimper as the

male crawls toward them.

The pups belong to the

alpha, or dominant, female.

She and her mate began

their pack only a year ago.

During the past summer, a

caribou’s kick broke her

mate’s jaw. He died from the

wound. The alpha female

welcomes a new mate.

The pack roams the

tundra looking for prey. Six-

month-old pups are too small

for pursuing caribou or musk

oxen. They begin hunting

lessons with lemmings and

snowshoe hares.

A female pup chases a

hare through the snow. The

hare leaps, zigzags, and scur-

ries to escape. The pup is

too inexperienced to deal

with such active prey. After

fifteen minutes, she returns

to her mother and flops

down exhausted.

In midwinter, the pack

comes upon a small herd

of musk oxen.

Working together,

they single out an

elderly bull. The

bull is already

weak from age

and illness. The

wolves attack.

Wolves use only

their teeth against

prey. It takes all

their strength and

effort to bring

down the bull.

71


� Two young wolf cubs dig in the Arctic snow.

WORDS TO KNOW . . .

dominant (DOM-uh-nuhnt)

leading or head

?

WATCH IT!

Following the Tundra Wolf

[ASIN: 6302775418] is a remark-

able video, worth seeing more

than once. It presents a full pic-

ture of the challenges and

struggles tundra wolves face in

their daily fight to survive.

�

Wolves play an important

role in keeping musk oxen

and caribou herds healthy

and strong. The wolves prey

only on the sick, elderly, or

injured. In that way, healthy

herd animals survive to mate

and produce healthy young.

The musk ox provides a

feast for the pack. However,

wolves eat in a specific order.

The alpha male eats first.

His mate eats next. A pup

tries to muscle in on the

carcass. He gets a warning

growl from the alpha male.

Wolf parents teach their

children good table manners.

March arrives. It is

breeding time for wolves.

Only the alpha male and

female produce young. The

new pups are born in late

May or early June. The moth-

er nurses the litter in the

den. Her mate and other

pack members hunt for food

and bring meals to her. The

pups are never left alone.

72


The new pack is secure.

It has three adults, three

juveniles, and four new pups.

Next year, the juveniles will

be old enough to leave and

start packs of their own. They

will find mates and

teach their pups

to hunt lemmings

and hares. That is

the cycle of life for

tundra wolves.

73

WORDS TO KNOW . . .

juveniles (JOO-vuh-nilez)

young, not yet having reached

adulthood

?

� A cave between the rocks serves as a den for members of this wolf pack.

� Spring comes late to the

Arctic tundra. At the end of

June, wildflowers sprinkle the

land with bursts of color.

Insects swarm by the millions.

And 15 percent of the world’s

bird population

arrives to breed.

Arctic tundra pro-

vides ideal nesting

grounds for

waterfowl, shore-

birds, and song-

birds. The area

has plenty of

lichens, mosses,

wildflowers, and clumps of dry

land on which to nest. As sum-

mer approaches, longspurs

sing their enchanting tunes

across the open spaces.

Nesting loons, swans, and

TheBreedingSeason

8Th

e B

reed

ing

Seas

on

74

[ C h a p t e r E i g h t ]

Snow geese take flight on their way to their Arctic breeding grounds. �

WORDS TO KNOW . . .

shorebirds (SHOR-burdz) birds

that live at the water’s edge,

such as sandpipers, snipes,

or plovers

waterfowl (WAW-tur-foul)

swimming birds, such as ducks,

geese, or swans

?

snow geese add their hoots

and honks to the chorus.

Tiny snow buntings and

plovers brave the rugged tun-

dra for the breeding season.

Snow buntings raise their

TUNDRA SWANS IN THE NEWS

Cornell University researchers and scien-

tists from Virginia, Maryland, Pennsyl-

vania, and North Carolina are studying

the migration routes of tundra swans.

Scientists want to know where the

swans breed and what flight paths they

travel. They also want to know where

tundra swans spend winter months.

Scientists captured and marked tun-

dra swans. The swans now wear leg

bands, neck collars, and radios. Daily

locations of different swans are record-

ed by the scientists.

The study will help scientists preserve

tundra swans and other birds that

migrate along the same routes. Human

understanding of how swans live holds

the key to their survival.

75

young farther north

than any other land

bird. They prefer

rocky, rugged

northern coasts,

where fewer preda-

tors will attack their

young. Plovers lay

their eggs in the

open. However,

they have excellent

camouflage. Few predators

can spot plovers or their eggs

from the sky.

More than 180 bird

species breed in the Arctic.

They arrive for the spring

thaw. Building nests and

laying eggs requires urgent

attention. Eggs usually hatch

within three weeks.

Then the race is on.

Parent birds gorge their

young with insects, worms,

and fish. The young must be

able to fly before winter

snows begin to fall. Migration

south may start only three or

[ T h e B r e e d i n g S e a s o n ]

WOULD YOU BELIEVE?

Golden plovers are excellent

actors. When a parent plover

spots danger approaching, it

draws predators away from the

nest. The plover pretends to

have a broken wing. The preda-

tor follows the parent but then

is disappointed. As the predator

pounces, the plover flies away.

!

four weeks after chicks hatch.

Snow geese are regular

summer residents of the tun-

dra. Their black-tipped wings

stand out against snowy white

bodies. They nest in huge

colonies with as many as

200,000 breeding pairs. Snow

geese mate for life. When they

arrive in the tundra,

the mates quickly

build grassy nests.

Female geese

lay four or five eggs.

Females sit on the

eggs until they are

hatched in 22 or

23 days. Snow

77� A lesser golden plover migrates thousands of miles each year to reach its favorite

nesting area.

WATCH IT!

Discover the remarkable Arctic

in Arctic Refuge: A Vanishing

Wilderness (Audubon, 1991).

This film presents the lives

of tundra animals and the

effect humans have on

wilderness regions.

�

� A black-browed albatross grooms her young on the Falkland Islands. Albatrossesonly come on land when breeding.

78


� An Arctic tern chick waits with a gaping mouth for dad to bring home dinner.

geese parents take turns pro-

tecting and feeding their

young. Within a month, the

baby goslings take wing along

with the rest of the snow

geese. The goslings must fly

several thousand miles to

their winter homes.

Arctic terns travel

yearly from one end of the

earth to the other. That’s

amazing for a bird that

weighs only 4 ounces (113 g).

They nest and breed in the

Arctic in winter, and they

spend summer on islands

near Antarctica.

Breeding season finds

male Arctic terns zigzagging

through the skies to attract

mates. Tern nests are not

quite as comfortable as

grassy snow goose nests. The

mates dig shallow

holes in the

ground. They line

the nests with grass

and leaves. The

time from egg lay-

ing to migration is

about 45 days.

Many birds of

prey also breed on

the tundra. Arctic

peregrine falcons,

merlins, jaegers,

rough-legged hawks, and

several types of owls nest on

grassy mounds. Long-tailed

jaegers lead double lives.

During the winter, they live

at sea, but summers find

them nesting happily on

land.

Swans, ducks, and geese

find ample food to support

79


WOULD YOU BELIEVE?

Arctic terns migrate farther

each year than any other bird.

Their annual round trip is about

21,750 miles (35,000 km).

!

LOOK IT UP!

The Arctic has an amazingly

large bird population. Learn

more about Arctic birds at

www.mnh.si.edu/arctic/html/

birds.html.

�

both parents and chicks. This

is not always true for birds of

prey. Hawks, jaegers, and owls

depend on voles and lemmings

for food. If the lemming popu-

lation is low one summer,

these birds may not breed

during that season. They

do not bear young if there is

not enough food to feed the

baby birds.

By late August, migrating

birds head south. Some adults

leave their chicks. As soon as

they can, the young birds fol-

low their parents south. Flocks

of birds fill the skies in neatly

formed V-shapes. Only a few

80

� A long-tailed jaeger guards its eggs from potential predators. Eggs and chicks are easyprey for weasels, foxes, and wolverines.

Winter approaches. The snow geese form a classic “V” formation as they head south �

in the early autumn.

birds, such as the snowy owl

and the gyrfalcon, winter in

the Arctic. Then again, if lem-

mings are few and winters are

harsh, even the snowy owl

heads south for better hunting.

81


� A light spring rain drifts

across the European Alps. But

The HumanTouch

9Th

e H

uman

Tou

ch

82

[ C h a p t e r N i n e ]

this is no ordinary rain. It does

not bring forth delicate white

edelweiss or soft pink alpenros-

es. It does not encourage

alpine meadows to grow lush

and green. This rain carries

sulfuric acid and nitric acid.

This is acid rain. It burns

grasses, lichens, mosses, and

wildflowers of the tundra.

Acid raid comes from

burning fossil fuels, such as

oil, gas, or coal. Humans use

fossil fuels to power cars and

trucks, heat homes, and run

factories. Burned fuel pro-

duces emissions.

Emissions can be

smoke or clear

gases. Fossil fuel

emissions contain

sulfur and nitrogen.

These are basic chemical

83� What could destroy a pine tree like this? The answer is acid rain, a plague on forests

and alpine tundra.

� Coal burning stations like this one pour pollution into the air.

WORDS TO KNOW . . .

emissions (i-MISH-uhnz) things

that are sent off or out, such

as gases

?

elements found in

nature.

When amounts

of sulfur and nitro-

gen combine with

elements in the air,

they form acid. The

acids exist with

water vapor in our

atmosphere. When rain falls,

so does the acid.

Acid rain is only one

form of pollution damaging

alpine and Arctic tundra.

Factories create pollution

by the bucketful. Chemical

pollution, air pollution, and

radioactive pollution take

84

WORDS TO KNOW . . .

atmosphere (AT-muhss-fihr)

the layer of gases that sur-

rounds the earth

radioactive (ray-dee-oh-AK-tiv)

giving off rays from atoms;

high levels of radioactivity kill

humans, plants, and animals

?

� This mine at Longyearbyen on Spitbergen Island, Norway, is in the heart of polarbear country.

their toll on this surprisingly

fragile environment.

In Norway’s Svalbard

Islands, polar bears face seri-

ous chemical pollution from

PCBs. Scientists think that

PCBs from European factories

got into river water and even-

tually into European seas. Fish

living in water with PCBs

carry the chemicals in their

bodies. Polar bears eat large

amounts of fish. The PCBs

collect in polar bear fat.

Scientists believe PCBs may

cause strange changes in polar

bear bodies. Eventually, they

can cause death. During the

1980s, most nations outlawed

the production of PCBs.

The air carries chemical

and radioactive pollution. One

of the worst polluting events

to affect the tundra

happened in 1986.

A nuclear power

plant at Chernobyl,

Ukraine, in the for-

mer USSR, released

radioactive particles into the

air. Wind carried the radioac-

tive particles to the Russian

tundra. This is where the

Saami people live.

Saami homeland covers

parts of Russia, Sweden,

Finland, and Norway. The

Saami depend on reindeer for

food and use their hides for

clothing and shoes. Radio-

activity from Chernobyl poi-

soned the plant life on the

Kola Peninsula in Siberia.

Reindeer eating the plants

became poisoned. The Saami

people could not risk eating

85

[ T h e H u m a n T o u c h ]

WORDS TO KNOW . . .

PCBs chemicals called poly-

chlorinated biphenyls, which

are poisonous to animals and

humans

?

lution lasts hundreds of years.

This event has changed the

ecosystem for many more years

to come.

86

reindeer—even though it was

their main source of food.

The government tried to

help. However, radioactive pol-

� This alpine landscape has been polluted by the radioactive spill at Chernobyl, Russia.

Oil, Gas, and the Arctic Tundra

� Humans use oil and gas

in huge amounts. Oil and gas

provide power for cars, boats,

and lawn mowers. They fuel

airplanes and trains. They

run power plants and facto-

ries. The need for oil and

gas makes oil companies

look in many places for fos-

sil fuel sources. One such

place is the North Slope of

Alaska. The drilling spot is

Prudhoe Bay.

Every oil well produces

dirty water, sludge, and a dis-

charge called mud. All of that

gets poured over the tundra.

The land cannot absorb the

huge amounts of muck that

is dumped there.

Efforts to

reseed Prudhoe

Bay’s tundra with

plants have failed.

It takes hundreds

of years for lichens

to grow to the size

of a softball. Deli-

cate tundra plants

cannot rebound

from pollution with-

in only a few years.

Oil companies

now want to drill in

the Alaska National

Wildlife Reserve

(ANWR). The

ANWR contains 19

million acres (7.7 million

hectares) of clean, natural

wilderness. It does not have

electricity, cars, or garbage.

ANWR does have 300,000

87


DO IT!

Write letters to your U.S. repre-

sentatives and senators. Ask

them to keep the Alaska

National Wildlife Refuge safe

from oil drilling. You’ll find their

names and addresses in the gov-

ernment section of your tele-

phone book.

��

READ IT!

Land of Dark, Land of Light: The

Arctic National Wildlife Refuge

by Karen Pandell (Penguin

Books, 1993) takes readers to

one of the last truly wild

regions in the world.

�

snow geese that nest there

each summer. Herds of cari-

bou and musk oxen browse

on Arctic plant life and try to

avoid local bears and wolves.

Snowy owls and eagles soar

overhead. Lemmings, voles,

and Arctic ground squirrels

burrow into the shallow soil.

This region cannot survive

drilling and the mess that

comes with it.

GLOBAL WARMING IN THE NEWS

Global warming is a by-product of rising

earth temperatures over long periods.

Car and truck emissions, home and facto-

ry heating, and large cattle farms are

partly to blame for global warming.

Scientists believe that global warming

is changing Arctic ice. Arctic ice sheets

are melting, and shrubs are spreading on

the tundra. Data shows that the area of

melting ice has grown by 16 percent in

the past 20 years.

“Shrubs are pushing farther north-

ward, growing in areas of tundra that

were void of trees as little as 50 years

ago,” says F. Stuart Chapin III of the

University of Alaska, Fairbanks.

88

Saving the Tundra

� Governments realize that

tundra environments teem

with life. Several huge national

preserves have been set aside

for tundra regions. In the

Rocky Mountains, Glacier

National Park (United States)

and Banff National Park

(Canada) are two large pre-

serves. Similar parks exist in

Asia’s Himalayas, the

European Alps, and South

America’s Andes Mountains.

Beringia International

Heritage Park is a preserve

run by both Russia and the

United States. The park pro-

tects land and marine animals

in Alaska and Russia. Musk

oxen, caribou, and polar bears

are among the animals roam-

ing the park.

89

� One spill at this Colville River ARCO plant could damage the surrounding tundrafor decades.

International efforts to

save flagship species have pre-

served many Arctic and alpine

species. Canada, Greenland,

Russia, and the United States

worked together to rebuild

musk oxen herds. Today, that

species is no longer endan-

gered in the wild. Several

nations protect polar bears

from hunters. By their actions,

governments are reducing

pollution and habitat loss that

affects these species.

Overhunting of snow leop-

ards, vicuñas, and yaks drastical-

ly reduced the numbers of those

animals. Today, governments

provide protected land for these

species. They keep a sharp look-

out for poachers who kill those

animals for their skins.

Native tribes work hard

to protect species on their

tribal lands. Wolves and musk

oxen benefit from attentive


not bounce back

from human abuse.

When polar bears,

snow leopards, and

mountain goats no

longer trek the tun-

dra, the loss will be

ours. Extinction is

a problem with no

solution.

native keepers. Native people

still kill some animals for

meat and skins. They do so

for subsistence living. Hunt-

ing for subsistence living is

allowed by law.

Tundra is fragile. It can-

not withstand oil and gas

drilling, overhunting, or pollu-

tion. Tundra ecosystems can-

91� A musk ox grazes on wildflowers in Alaska.

� The U.S. Park Service protects this regal landscape, which is found in Denali NationalPark, Alaska.

WORDS TO KNOW . . .

subsistence living (suhb-SIS-

tents LIV-ing) humans using

local plants and animals in

order to live; when people rely

on what they are able to pro-

duce themselves instead of a

cash economy

?

Char

t of S

peci

es

92

[ T u n d r a ]

� The above chart gives a starting point for identifying key species. Each tundra environment has its ownkey species. The above chart lists some of those species.

Note: Caribou and reindeer are the same species. In North America, the wild species are called caribou. InEurope, they are caribou or reindeer, depending upon the location. In Siberia (Asia), they are called reindeer.

[Bold-faced entries are the ones discussed in the text.]

CONTINENTKEYSTONESPECIES

FLAGSHIPSPECIES

UMBRELLASPECIES

INDICATORSPECIES

AFRICA(MT. KILIMANJAROONLY)

bees, beetles lammergeiers,giant lobelias

lammergeiers lichens, sedges,tussocks, insects

ASIA pikas, bees,beetles, reindeer,gray wolves

Siberian cranes,marmots, snowleopards, muskoxen

Asiatic black bears,snow leopards,wild yaks, muskoxen

lichens, sedges,tussocks, insects

EUROPE reindeer, pikas,bees, beetles, graywolves, chamois,caribou (reindeer),lemmings

polar bears,wolves, chamois,lynx

polar bears, arcticwolves

polar bears,lichens, sedges,tussocks, insects

NORTHAMERICA

caribou, pikas,pocket gophers,bees, beetles, graywolves, snowgeese, lemmings

wolves, polar bears,caribou, grizzlybears, peregrinefalcons, musk oxen,Rocky Mountainbighorn sheep

grizzly bears, polarbears, Arcticwolves, RockyMountain bighornsheep

polar bears,lichens, sedges,tussocks, RockyMountain bighornsheep, white-crowned sparrows,insects

SOUTHAMERICA

bees, beetles guanacos, vicuñas guanacos, vicuñas lichens, sedges,tussocks, insects

our living world: earth's biomes - volume 2: tundra

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