PLANET EARTH: Deserts
Animal Guide
Grade Level: 3-12 Excerpted from PLANET EARTH Animal Guide written by Jennifer Viegas and
Wendee Holtcamp. The guide is available in its entirety at http://dsc.discovery.com/
convergence/planet-earth/animals/animals.html.
Wild Bactrian Camel
Introduction
Deep within the Asian continent, the last few hundred wild Bactrian camels survive in one of
the harshest environments on earth. Known as the “Great Stony Desert,” the Gobi is bordered
by massive sand dunes and mountain massifs, with vast stretches of sandy desert in between.
Snowy and cold in winter and blazing hot in summer, the Gobi Desert is a land of extremes.
Wild Bactrian camels have behaviors, physiology and body morphology exquisitely adapted
to life in the Gobi. Unlike domesticated Bactrians or dromedary camels, wild Bactrian camels
can survive heat and cold, drought and famine, wind and snow. Wild Bactrian camels have two
triangular-shaped humps, they eat vegetation, and their tough mouths can handle even thorny,
prickly desert plants. They have long eyelashes and can shut their nostrils to keep out flying
sand. Domesticated Bactrians are genetically different from wild Bactrian camels and were
domesticated over 4,000 years ago.
Unique Behaviors
Wild Bactrian camels can drink salt water, whereas domesticated Bactrian camels will not.
Scientists still don’t understand quite how the wild animals physiologically process the salt water,
but it allows them to inhabit regions of the Gobi Desert in China where only saltwater, but no
freshwater, springs exist. Scientists have found a few skeletons of young camels, and think that
perhaps they were not able to go directly from milk to salt water.
Bactrian camels can survive times of drought and famine, storing reserves of fat in their humps,
and excess water in their bloodstream. Biologists found that Bactrian camels have an extremely
tough immune system, resistant to foot-and-mouth disease, mad cow disease, Rift Valley fever,
and others.
Status and Conservation Efforts
Less than 1,000 wild Bactrian camels wander throughout the vast Gobi Desert, which includes
Mongolia and western China. As of 2002, The World Conservation Union (IUCN) uplisted the
Bactrian camel from endangered to critically endangered, with threats to the species increasing
and the population declining. Threats include hybridization with domestic Bactrian camels,
predation by wolves, habitat loss and hunting.
Extended drought has dried many watering holes in the Gobi, and wolves gather at remaining
oases in the mountainous portion of their range in China and Mongolia to prey on the camels.
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Overgrazing, as well as legal and illegal gold, iron ore, copper, and coal mining in China,
disturbs vast portions of the Bactrian camel’s desert habitat, particularly due to the use by
miners of lethal potassium cyanide. Illegal miners sometimes kill wild camels for food. Local
herders also kill wild Bactrian camels because they compete with domestic camels and
livestock for precious water and food resources. Sometimes domesticated camels get loose,
and breed with their wild cousins. Hybridizing with their domesticated cousins mixes up the wild
and domesticated camel genes, affecting the wild camels’ fine-tuned desert adaptations.
Dromedary Camel
Introduction
Used for centuries as beasts of burdens, the long-legged one-humped dromedaries or Arabian
camels have been raced in Arabia, served as pack animals, and formed part of the Roman
camel warriors corps. In Arabia, every part of the dromedary serves a purpose. Their hides
make tents and their bones are a substitute for ivory. They provide milk and meat, and can
carry a rider 80 to 120 miles in a single day. Dromedaries went extinct in the wild 2,000
years ago, and all of the individuals found in the wild today are domesticated or feral (domestic
individuals that went wild). Today dromedaries live in the Sahara Desert of northern Africa and
western Asia—the world’s largest desert—as well as in the Australian Outback.
Unique Behaviors
Males dromedaries defend a harem of females and their offspring, and will spit, bite and butt
anyone who encroaches. Males fight one another with their tough necks. If a conflict escalates,
it can result in serious injuries. During breeding season, males extrude a piece of their mouth,
the soft palate, which looks like a red balloon. They will also form copious amounts of saliva,
which turns to a frothy foam.
Status and Conservation Efforts
Dromedaries went extinct in the wild sometime after they were domesticated in Arabia,
between 4,000 and 2,000 B.C.E. Today, all wild dromedaries are considered feral. They
range throughout North and East Africa, and southwest Asia. They’re still widely used as
domesticated pack animals in western Asia and northern Africa. Australia has a large feral
population that is doubling every decade, causing some conservation concern.
Red Kangaroo
Introduction
The world’s largest marsupial, red roos travel in mobs with a dominant male “boomer” and
several females and their offspring. They can hop at speeds of 40 miles per hour, using their
strong, elongated tail for balance. When moving slowly, hopping becomes an inefficient mode
of locomotion, so they balance on their tail and forearms, and swing their hind legs forward like
a pendulum.
During breeding season, males get feisty and kickbox one another over females. The grumpy
males will hold one another’s forearms, kicking the other straight in the gut. Their large feet
have a big claw that can disembowel their opponent.
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Unique Behaviors
The joey, or young kangaroo, is one of Australia’s most famous faces. Whether peeking out
of its mother’s pouch or climbing in headfirst, their antics are endearing. Born just thirty-three
days after fertilization, the joey crawls across mom’s stomach as a blind, hairless one-inch
creature. It reaches the pouch, climbs in and attaches to a teat, where it remains for the next
several months. As the joey gets older, it grows fur and pokes its head out of the pouch. By
nine months, the joey grazes alongside its mom, but continues to suckle until around 1one
year of age.
Mom mates again soon after she gives birth, and her body holds the embryo in a suspended
state called diapause until her older joey leaves the pouch or environmental conditions grow
favorable. Mother red kangaroos can nurse joeys of two different ages, producing different
kinds of milk from different teats.
Status and Conservation Efforts
Red kangaroos remain abundant, with millions existing across most of the drier parts of
Australia—around 60 percent of the continent. In the late nineteenth century, people
received bounties to shoot kangaroo, which were considered vermin. In the 1950s, the hunt
switched to commercial harvest for skins and meat, and later, for pet food. Around the 1970s,
conservation concern led to the creation of hunting quotas, and now only licensed commercial
wildlife shooters can hunt kangaroos. Around 3-4 million red kangaroos are hunted annually
for skins and meat, which gets sold within Australia and exported. The numbers permitted for
harvest are based on aerial surveys undertaken by state conservation agencies.
Populations of red kangaroos stay much higher inside Australia’s Dingo Fence, a sprawling
3,300-mile structure that stretches across Queensland, New South Wales, and South Australia
to keep dingoes—wild dogs—out of the sheep-harvesting areas. “A huge amount of effort
has gone into kangaroo conservation and management in this country in the last thirty years
or so and it is pretty much a success story,” says University of Queensland Professor Gordon
Grigg. “They are, after all, really fantastic animals, no matter where you live.”
Pale Fox
Introduction
South of Africa’s Sahara Desert lies a little-known region called the Sahel, a band through
north-central Africa of arid scrub savannah. Not perennially dry like the Sahara Desert, the
Sahel is instead characterized more by environmental instability—years of drought followed by
monsoons or periodic rainfall. The pale fox lives here, preferring the arid parts of the Sahel.
The cliff-dwelling Dogon people of Mali hold the pale fox in high regard, as it is one character
in their creation legend. A Dogon diviner will pose a question, recite an invocation to the fox,
and place peanuts on the ground. When the fox comes at night to take the peanuts, it leaves
scratches in the sand that reveal the answer.
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Unique Behaviors
Pale foxes may actually prefer vegetation, including berries, melons, wild fruit and other plant
matter. They have well-developed molars, which generally suggests herbivority. Pale foxes will
devour small animals—from mice to insects—when they can catch them.
The pale fox rests by day in underground burrows, which can be extensive and have inner
chambers lined with dry vegetation. At night they emerge to explore and forage. The desert
cools, and animals emerge from their daytime hiding spots. The pale fox typically travels in
small packs of a few animals.
Status and Conservation Efforts
Scientists know so little about the pale fox’s status that the World Conservation Union (IUCN)
lists it as “data deficient.” It lives from Mali and Senegal in the west to Somalia in the east, and
although it ranges across a vast stretch of Africa’s Sahel, it is often locally rare. They may sneak
into cultivated fields or close to human habitation where food may be more abundant, and this
can lead to persecution by locals.
Gila Woodpecker
Introduction
Gila woodpeckers nest in saguaro trunks—tree-size cacti that grow up to forty feet tall and
live 200 years. A desert specialist common throughout the Sonoran Desert of Mexico and
southwestern United States, the Gila woodpecker has zebra-like wings, with a tawny chest and
head. Males have a red cap of feathers. They dine on cactus fruit, mistletoe berries, beetles,
ants, grasshoppers and other critters that live in and around the saguaro. They also sometimes
nest in cottonwood and mesquite trees.
Unique Behaviors
After the Gila woodpecker drills a hole in the saguaro, it does not take up residence for several
months. This allows the pulp to form a casing around the inner part of the future nest site. The
cactus secretes a tough substance that heals its “wound” to prevent moisture loss. Once they
inhabit the nest, it provides a cool respite from the heat. On hot summer days, the temperature
inside the nest cavity stays twenty degrees cooler than outside.
Male and female Gila woodpeckers tend to forage differently. Males spend more time on larger
branches and trunks, and males also peck for subsurface insects more often, whereas females
spend time on smaller branches and diseased areas of the cactus, and prefer to glean insects
from the surface rather than pecking for insects.
Status and Conservation Efforts
Found in Baja and western Mexico, Arizona, and parts of southern California and New Mexico,
the Gila woodpecker is locally common and abundant. However, according to the Cornell
Lab of Ornithology, some Gila woodpecker populations may be declining, largely because of
development around the Sonoran Desert ecosystem and competition with non-native European
starlings.
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Lesser Long-nosed Bat
Introduction
Lesser long-nosed bats migrate long distances, leaving their wintering grounds in southern
Mexico every spring to fly to the southwestern United States. There are a few resident colonies
that don’t migrate from southern and central Mexico. Lesser long-nosed bats have evolved
a mutually beneficial relationship with many desert plants in the Sonoran Desert, which
encompasses Sonora, Mexico and southern Arizona. The bats gorge themselves on nectar
from the night-blooming flowers of agaves (century plants), saguaro and organ pipe cactus,
and the plants get their flowers pollinated.
Lesser long-nosed bats have long tongues with a brush-tip that reaches the copious nectar
deep inside the flower. The “long-nose” moniker comes from their narrow, elongated nose,
but they also have a triangular flap of skin at the end of their nose. In the process of drinking
nectar, their fur gets coated with pollen, which gets rubbed off on the next flower visited.
The bats drink so much nectar that when full, their stomachs resemble a late-stage pregnant
female!
Unique Behaviors
Migratory lesser long-nosed bats breed in southern Mexico in November and December, giving
birth once they reach their summer roosts in the southwestern U.S. or northwestern Mexico.
Some individuals appear to be non-migratory within the same range. Thousands of females
gather in maternity roosts, often in caves or mine shafts, with each female giving birth to a
single pup. Snuggling in close quarters provides an optimal temperature for pregnant females
and the growth of the young pups. Despite being highly gregarious, lesser long-nosed bats
don’t groom one another or care for each other’s young.
When roosting, they hang with their feet close together so they can swivel their body around
360 degrees to scout for predators. When they take off, a few powerful wing beats bring their
body into a horizontal position, and then they release their grip.
Status and Conservation Efforts
The lesser long-nosed bat is an endangered species in the U.S. and Mexico, and The World
Conservation Union (IUCN) lists them as vulnerable. Some people mistake lesser long-nosed
bats for similar-sized vampire bats, and kill them out of fear and misunderstanding, even
eradicating whole colonies. Around 400 years ago, native Mexican cultures took the native
agave and extensively planted and cultivated it. Overharvesting of agave in the past, as well
as the decline in cultivation, may have impacted one of the bat’s primary food plants. Different
species of agave flower in spring, summer and fall, and the agave, along with other desert
succulents, may provide fuel for the bats’ long migration.
In southern Mexico, some of their caves lie on protected lands, but the caves used by migrating
bats remain largely unknown. The bats migrate through the regions of Nayarit and Sinaloa,
Mexico, which are also known to have heavy drug trafficking. Drug traffickers may hole up in
the same caves, and people’s campfires—or their presence alone—may drive the bats away.
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Nubian Ibex
Introduction
Smaller than most ibex, the graceful Nubian ibex dwells in rocky cliffs of the Middle East and far
northeast Africa. Both males and females have horns, but males’ horns grow
to enormous lengths and curve backward in a semicircle. Older males also grow billy-goat
beards.
Nubian ibex live in small herds of all males or all females. Active mostly by day, but also at
dawn, dusk or evening in the hot summer in some regions, they graze on grasses and other
vegetation. They must drink water daily to survive. This endangered species has lost ground to
habitat degradation throughout most of its range.
Unique Behaviors
Nubian ibex have a symbiotic relationship with Tristram’s grackles. The brown- and blackcolored birds land on the ibex and eat insects from their fur. The grackle gets a meal, and
the ibex gets rid of ectoparasites. This is one of only a few known bird-herbivorous mammal
relationships in the world; others include the cattle egret, scrub jays on black-tailed deer in
North America, and oxpeckers on zebra, giraffe and Cape buffalo in Africa.
Status and Conservation Efforts
Not long ago, taxonomists listed all ibex as races of a single species but have since separated
them. Nubian ibex have a patchy distribution, with isolated populations in rocky cliffs of
northeast Africa and Arabia, including Sudan, Eritrea, Saudi Arabia, Oman, Egypt and Israel.
People have hunted Nubian ibex for centuries, and despite their listing by IUCN (The World
Conservation Union) as endangered, poaching still occurs. Trophy hunting still takes place in the
Red Sea Hills of northern Sudan, and CITES (Convention on International Trade in Endangered
Species) does not regulate or monitor trade in Nubian Ibex, despite it being an endangered
species.
Augrabies Flat Lizard
Introduction
At the southwestern edge of the Kalahari Desert, dense aggregations of rainbow-colored
Augrabies flat lizards gather in solid granite rock outcroppings alongside the Orange River.
Water provides a vital source of life in any desert, and this river is no exception. In all the world,
the Augrabies flat lizard lives only within a narrow belt on either side of an approximately fiftymile stretch of South Africa’s Orange River.
The females’ drab brown color matches the rocks, but males have brilliant rainbow-colored
bellies, heads and legs, which they use to settle territorial disputes with any male that gets too
close—and possibly to attract mates.
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Unique Behaviors
Augrabies flat lizards have compressed bodies that they can flatten against the rocks they live
in—hence the name “flat lizards.” When a rival gets too close, they turn their body so they
more fully expose their brilliantly colored bellies and puff out their throats. Besides a brilliant
blue head and throat, underneath the males’ front and hind limbs—their armpits, if you
will—are patches of brilliant yellow and orange. The younger males’ backs and tail are mottled
brown, like the females.
Professor Martin Whiting of South Africa’s University of the Witwatersrand found that Aubgrabies
flat lizard throats reflect an ultraviolet (UV) signal that other lizards recognize. The richer the
UV color, the more likely a male is to win a battle. As they age, a male’s coloration deepens
and spreads to his back—reflecting that this more dominant male is a better fighting foe
and a better mate. The signal seems to honestly reflect the males’ fighting ability, so prevents
battles—unless the aggressor is the same size. “This is the only lizard - and reptile - in which
UV signals male status or fighting ability,” says Whiting. “There are only a few other examples
of this in the animal kingdom.”
Status and Conservation Efforts
Augrabies Falls National Park protects the easternmost portion of the species’ habitat, which
extends an additional fifty miles westward outside the park along the Orange River. “They
are very, very common, but they have a tiny range,” says Scott Keogh, an Australian National
University professor who collaborates with Whiting. With such a narrow range, any future habitat
destruction could impact the species. A few wineries have sprung up near the river, but they do
not occupy the solid granite along the river’s edge used by the lizards, and much habitat still
remains.
Martin Whiting’s research has brought international interest in the Augrabies flat lizard, and
people—especially “herpers,” or reptile and amphibian enthusiasts—travel from around the
world to catch a glimpse. This can continue to create an economic incentive to preserve the
species and its habitat.
South African Oryx
Introduction
Exquisitely adapted to hot, arid desert, the strikingly beautiful South African oryx, or gemsbok,
thrives where other large animals can’t. Able to go weeks without water, they garner moisture
from the grasses they graze, and they will dig for roots when grass is unavailable. Their body
temperature can measure over 110 degrees Fahrenheit, and they stop sweating to conserve
water.
The desert plants that South African oryx eat have adaptations to absorb dew, and oryx
feed during times of day when plants have their highest water content—early mornings, late
evenings and moonless night. Both males and females have two long, spearlike horns; and
black and white markings on their face and legs; and a fawn-colored body.
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Unique Behaviors
South African oryx live in herds with both males and females, and they follow a strict
dominance hierarchy. Only the dominant male mates. The younger animals play-fight, but
their games play an important role in establishing the younger animals’ strength, which is one
determining factor in their social rank. Older animals engage in ritualized posturing and display,
rather than outright fights; the more the animals can establish rank without a real fight breaking
out, the less chance someone will get injured. In the rainy season, over a hundred oryx may
make up a herd; in the dry season, they tend to form smaller groups of ten to thirty animals.
When it’s time to give birth, the mother leaves the group, keeping her calf hidden for up to six
weeks. Only then does she rejoin the herd. The whole herd protects the females’ calves. When
a hyena approaches—a ravenous predator—the oryx will gather around in a circle facing
outward, with calves in the middle.
Status and Conservation Efforts
IUCN (The World Conservation Union) lists the species as lower risk, conservation dependent.
In other words, enough gemsbok exist to sustain the population, so long as conservation
efforts continue to work to ensure their survival, and other threats do not arise.
Lion
Introduction
With its flowing golden mane, the male lion inspires both awe and fear. Persecuted by people
and hunted as trophies for many millennia, the lion has declined throughout its range, and
continues to do so. The only truly social cat, they live in prides with one male or a coalition of
brothers, several females and their offspring.
“King of the Jungle” is an odd moniker for the lion. Lions live in just about every habitat except
jungle! Lions prefer open woodland and savannah, but also can be found in desert, plains, and
scrub forest. You will not find them in a rain forest.
Unique Behaviors
When a male—or a coalition of brothers—successfully takes over a pride from a rival, he kills
all the cubs under two years old. Losing the cubs brings the females into estrus, so that he can
mate with the females, and sire his own cubs. In the animal world, infanticide ensures that the
male devotes his time to protecting his own offspring.
Status and Conservation Efforts
Once found throughout nearly all of Africa as well as through the Middle East and India, today,
only isolated populations remain. In Africa, lions live south of the Sahara Desert, but available
habitat remains fragmented and largely unprotected. Estimating Africa’s lion numbers is difficult,
but surveys in 2002 estimated the population as between 29,000 and 47,000. The African
lion is listed by The World Conservation Union as vulnerable to extinction, while the Asiatic lion
is critically endangered with only a couple hundred animals left.
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Rural people kill lions throughout their range out of retaliation for livestock and “man-eating.”
Dr. Craig Packer and colleagues showed that lion attacks on people in Tanzania, which has the
largest lion population in Africa, have risen sharply in the past fifteen years. Attacks occurred
more often where the lion’s natural prey was scarce, and where nocturnal crop-pests—mostly
bush pigs—forced people to sleep in their fields. The scientists recommended locals clear their
land of bush hogs, since lions get attracted to the sleeping villagers while in pursuit of bush
pigs.
Published by Discovery Education, Inc., a division of Discovery Communications, LLC. © 2007. All rights reserved. Based on
PLANET EARTH © BBC. Distributed under exclusive license from Educational Publishers LLP.
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