Tropical Savanna by skye harnsberger

NATIONAL N AT I O N A L G E O G R A P H I C . C O M / M A G A Z I N E

M AY 2 0 1 2

GEOGRAPHIC the

African ELEPHANT race to save this gentle giant Career Spotlight Vegetation Visitation Animal Adaptation Community Interactions

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NATIONAL

VOL. 221 • NO. 4

GEOGRAPHIC

31 A mother giraffe nuzzles her calf in Mikumi National Park, Tanzania.

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Editor’s Note

Hear what the editors had to say about this issue.

Skye Harnsberger, Elizabeth Clarke, and Maddy Goodwin

Visions

Peek into the world of the African Savanna by gazing at our spectacular photos of the wildlife and landscape. Compiled by Skye Harnsberger

Letters

Check out the feedback from our readers about the magazine itself.

Various contributers

Photographs by various contributers

Explorers Journal

Heading to the savanna for a safari trip? Make your packing list according to our trusty temperature & rainfall guide. Find all your info about climate here. By Elizabeth Clarke

Cartoon

Get a nerdy giggle out of our newest creative piece! By Maddy Goodwin

Geography

Learn all about the landscape of the African Savanna with a detailed map and information on geographic structures and culture. By Elizabeth Clarke

U N O F F I C I A L J O U R N A L O F T H E N AT I O N A L G E O G R A P H I C S O C I E T Y

May 2012 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

Limiting Factors

Understand more about the environmental influences that constrain the productivity of the flora and fauna in the savanna. By Elizabeth Clarke

Career Focus

Read an interview with a biologist that works in the field in Africa. She elaborates on a few conservation efforts currently in effect as well. By Elizabeth Clarke

Plant Life & Adaptations

Focus your attention on these six unique plants that inhabit the African Savanna and see how they have adapted to overcome limiting factors By Maddy Goodwin

Animal Life & Adaptations

Check out the daily lives of six specially chosen wildlife species. By Elizabeth Clarke

The African Elephant

Read our cover story on the mystical and endangered African Elephant and how humans are threatening their existence. By Skye Harnsberger

Community Interactions

We provide you with a sketch of the food web in the African Savanna. Find out what kind of symbiotic interactions take place as well. By Maddy Goodwin

A meerkat scouts out his territory.

Come explore with us. PERSONAL GUIDES • CLOSE EXPERIENCES

unset afari T O U R S

EDITOR’S NOTE

Surfing Safari They say the third time is the charm, but we’ve edited this magazine many more than three times. By writing this many articles solely on the tropical savanna, we certainly have had our fill of learning about this one particular biome. Hopefully you find it as informational and creative as we tried to make it. We really wanted this last AP Bio project to help us go out with a bang. As you will see, the savanna is by far the most interesting biome of all. Not only do we have a prime habitat for extreme biodiversity, but the countries where our biome exists have excellent vacation spots and opportunities to get involved with conservation. I mean, who doesn’t want to go spot a cheetah in Africa or hop around with a kangaroo in the grasslands of Australia? Check out our ads to look at the best places to tour and to get the most out of your travel experiences. We hope you are inspired by our articles and entertained by the little snippets of humor here and there. This copy of National Geographic is obviously highly influenced by the real publications and hopefully you look out for the uncanny similarities. The formatting, fonts, and graphics are all based off of the real thing. We’ve worked hard, so we hope you find the magazine enjoyable and creative!

SKYE HARNSBERGER

ELIZABETH CLARKE

MADDY GOODWIN

the

a African ButterflyConservatory LET YOUR SPIRIT SOAR! There are over 4,000 species of butterflies in Africa and many of them live in the grassland regions of the country. Tour our winding butterfly path and experience for yourself the many different butterflies of the African Savanna. DISCOVER MORE AT www.africasbutterflies.com

Letters Timid Vacationer I just want to let you know about the amazing trip I took to the Tsavo National Park in Kenya last month. I have always been a timid vacationer, prefering a week at the beach to backpacking in the mountains. But I was totally inspired by your December article, “Vacation With Courage.” I went completely out of my comfort zone by visiting Kenya, and I don’t have one regret. Who knew coming within ten yards of a cheetah could be so eye-opening? Thanks for the inspiration! KAYLIE GEORGE Whiteston, KY

I look forward to your magazine every month with excitement, but lately I’ve been a little disappointed. You always provide us readers with interesting stories, but you fail to focus on ways we can help. For instance, I feel like you need to say more about conservation, especially concerning the African savanna. Did you know that cheetahs are in danger of extinction because of in-breeding? You should use your huge platform to get people involve in the world. DANIEL WHIT Germantown, PA

You absolutely need to do a story on the dangers of keeping wild animals in pets. A woman living five miles from me was recently found to have a leopard living in her house! Someone found out and called the police, and thankfully no one was hurt. But these kinds of things happen more than people know, even though they seem against all common sense. Some people don’t understand that animals such as leopards only belong in their natural habitats. We talk a lot about the mistreatment of dogs and cats, but wild animals are mistreated every day as pets. ZAHLA MARTIN Kenningway, TX

I wanted to write to you guys to notify you of a typo in your last issue. In your article titled “The Migration of the Elephants,” you said that the only use of the elephants’ large ears is to keep it cool by fanning. However, the ears of the African elephant also function to promote blood circulated in the head and enable the animal to have fantastically acute hearing. Please be aware of typos such like this in the future and know that some of your readers are fact checkers! Surely you will deserve an A+ on your next magazine if you follow my advice to be thorough and accurate. VIDYA KEYS Richmond, VA

CARTOON

MADDY GOODWIN

VISIONS

South Africa A small herd of gazelles meanders through the African grassland with an acacia tree in the distance. 10

South Africa A wild dog and her pup lie down and pant away in the dry heat of the savanna. 12

Nambia Four zebras gather at a watering hole to quench their thirst. 14

visions your shot

EDITORS’ CHOICE

This page features two photographs: one chosen by our editors and one chosen by our readers via online voting. For more information, go to ngm.com/yourshot

Paul Hennessy Kakadu National Park, Australia

Hennessy, 58, snapped this lucky shot of an adolescent kangaroo in Kakadu National Park in northern Australia. He has always had “a passion for photographing wildlife” and told us that he thoroughly enjoyed his trip to the Outback.

READER’S CHOICE

Herb Jones Nambia, Africa

Jones photographed this woman at a nonprofit concert for relief effors in Nambia. She has become a local celebrity ever since her singing career took off in Africa. Jones says that he enjoys taking portraits and was only in Nambia to complete a mission trip.

Look your very best - use Bare Biome Minerals.

Naturally derived formula from weathered oxisol soil content from the grasslands around the world. Features almost NO organic matter! Highly fortified with iron (III). Contains quartz to give you that extra sparkle. Also has small amounts of clay to give you maximum coverage.

explorers journal

Elizabeth Clarke

O GRAPH

IC CIE T Y

NAT I O N

M I S S I O N To explore and inspire discovery in the world’s biomes

FFI

0 C IA L A . D. 2

Founded in 2012, the (Unofficial) National Geographic Society has added to our knowledge of earth, sea, and sky by supporting less than 10,000 explorations and research projects. Readers’ membership dues make this support possible.

Plan your trip to... The African Savanna! When To Visit: Like all tropical savannas, the African savanna has distinct wet and dry seasons. The dry season sees less than four inches of rain annually and average temperatures of 68-78 degrees Fahrenheit, whereas the wet season is bombarded by 15-25 inches of rain and average temperatures over 80 degrees! Explore the African savanna during the dry winter months when there is little rain and (slightly) lower temperatures. If the Australian savanna is more your style, make sure to visit during the dry season from May to October. What to Wear: Humidity levels remain relatively low during the dry season, but the air stays hot. Pack light linens, comfortable hats, and plenty of sunscreen! Possible Dangers: During the dry season, huge fires frequently sweep the savanna. While they rarely prove harmful to animals, they can be dangerous to tourists unaccustomed to the seasonal changes of the

areas. Make sure to follow your guide’s instructions regarding fire danger zones. In addition, the wet season (beginning in April - May in Africa and September - November in Australia) is marked by huge rainstorms caused by strong monsoon winds originating from the equatorial region. These intense low-pressure systems can develop into tropical cyclones, causing widespread flooding and damaging winds. Where to Stay: Whether you’re a worldclass crocodile wrestler or pampered private-jet princess, the African savanna will be a trip you’ll never forget. Here are some of our favorite places to stay, ranging from bare-boned to barely lifting a finger. Serengeti Conservation Project Cabins Spend two months in wooden cabins on the Sergengeti Plains of Tanzania assisting savanna conservation efforts. Application is required. • Mt. Rugahami Lodges These classic lodges offer all of the basic amenities at an amazing price, but the real treat is the world-class Safari tours. • Asa Pride Resort and Spa Recently opened by two Americans with years of hotel experience, this resort captures the beauty of the African savanna in a luxurious, peaceful setting.

Geography Found typically in the tropical latitudes, the

savanna biome? The tropical savanna is filled with

tropical savanna biome is characterized by tall

farming tribes such as the Dorobo, Kikuyu, and the

grasses and the occasional tree. This biome exists

Maasia. The mining of silver, nickel, gold, diamond,

in many different places around the globe such

and limestone is also common in this savanna

as Botswana, Namibia, Kenya, southern Brazil,

biome. But possibly one of the greatest and fastest-

India, and Australia. Defining land features are

growing enterprises in tropical savanna regions is

highly diversified. In some areas the landscape is

tourism. Tourists are attracted to the beautiful terrain

composed of rolling hills topped with high grasses,

and diverse wildlife, and consequently more and

a sparse scattering of trees, and rocky outcrops. In

more tourists have begun to visit tropical savanna

sharp contrast, certain parts of the tropical savanna

biomes.

are characterized by rocky plateaus and deep

The tropical savanna biome, with its harsh

gorges, even creeks and pockets of rainforest occur.

seasons and dry soil, has a surprising impact

These wide ranging differences in tropical savanna

on humans. Full of nomadic tribes and industry, it is

landforms fit into three general categories: black soil

an environment that many people truly

plains, savanna woodlands, and stone country.

rely on.

Soil in the tropical savanna is produced mainly

Possibly the most well-known tribe in the African

by the process of lateralization. This occurs when

tropical Savanna is the Maasai. They have lived in

deep soils leach calcite and silica dioxide, thus

the savannas of Kenya and Tanzania for hundreds

leaving behind iron and aluminum oxides. This

of years. Subsisting off of livestock such as cattle,

process results in red tinted soil. This soil is hard

sheep, and goat, the Maasai peopleâ&#x20AC;&#x2122;s way of

and compact, causing a layer of standing water to

life is heavily dependent on the tropical savanna

lie above the soil through the rainy season. During

environment. They live in huts composed of mud,

the dry season, the soil is very firm, therefore

branches, twigs, andgrass, materials that are easily

preventing the permeation of roots. One could

accessed in the tropical savanna.

guess that because of the inability of roots to penetrate tropical savanna soil it is generally not very fertile. This assumption is quite correct; not only is it hard for roots to physically enter the soil, but also oxisol soil, characterized by very low fertility because a lack of nutrients, high levels of phosphorus, and poor ability to hold cations, is quite common in the tropical savanna. So how do people interact with the tropical 20

Tropical Savanna Regions

During the harsh dry season, women walk many

The grazing industry in Australiaâ&#x20AC;&#x2122;s tropical

miles to find water for their families. The long dry

savanna is also critical to the people of this

spell in the tropical savanna also forces the Massai

region. The beef cattle grazing industry uses a great

to live a semi-nomadic life: men often have to move

potion of land in the Australian tropical savanna

their herds to find water.

and brings in millions of dollars a year. The industry

Additionally, industry in the tropical savanna

provides employment for thousands of Australians.

heavily affects people around the globe. Two major

Unfortunately, though, the harsh conditions of the

industries in tropical savanna regions are mining

tropical savanna profoundly affect the grazing

and grazing.

industry. Drought and flooding, both common in

savanna regions, must be taken into account for

Mining in tropical savanna biomes generates

a whopping 13.5 billion dollars a year, bringing

producers when thinking about long term stocking

in the largest profit of all industry in the tropical

rates. This is the simplest adaptation of the

savanna. This biome is filled with an abundance

industry made as a result of the tropical savanna

of valuable gems and minerals, such as bauxite,

environment.

copper, lead, zinc, silver, nickel, tin, gold,

manganese, uranium magnesite, diamonds, mineral

allowing the grazing industry to be more efficient

sands, phosphate rock, kaolin, limestone, and silica.

in tropical savanna environments. New breeds of

Coal and petroleum, two major resources in the

cattle more suited to the tropical savanna

modern world, are also mined in tropical savanna

environment have been introduced to the industry.

regions. The mining of all of these products is

These cattle are now fed additional

crucial to the people of the tropical savanna. Overall

nutrients, which allow herds to better endure

mining employees make up 15 % the work force

droughts.

Other adaptations have also been made,

in the savanna; without this industry, economies in tropical savanna regions would be profoundly affected. 21

Limiting Factors The tropical savanna is home to some of the world’s most

Manmade and natural fires frequently ravage the land

interesting animals and plants. From widespread grasses

during the dry season. Most animals can run from them,

to ferocious cats, the organisms that call this biome

but they prove detrimental to plants scorched by the

home have one trait in common: they have amazing

flames.

adaptations that allow them to survive against all odds. The factors that limit the productivity of life in the tropical

As with most living organisms, the survival of animals

savannah are numerous, yet it continues to be one of the

and plants in the tropical savanna is heavily influenced by

most biologically diverse biomes.

their predators. Many organisms have developed special adaptations that allow them to hide, or hunt, at their full

With a two-season climate, the tropical savanna goes

capacity.

through months with little rain. Water is not always easy to come by during the dry season, so animals

So with all of these factors fighting against them, just how

must resort to special measures. Likewise, it is not easy

do plants and animals survive in the tropical savanna?

for plants to adapt when the soil is dry for some of the

Turn to “A Day in The Life” and “Vegetation Visitation” to

year then steadily soaked for the other part.

learn about how organisms succeed in the wild biome that is the tropical savanna.

Tropical savannas are marked by generally low soil fertility, though it can vary depending on the location. Since dead tree matter releases nutrients into the soil after decomposition, the soil close to trees is often more fertile. Soil fertility tends to be lower in areas that receive heaver rainfall during the wet season because the land becomes stripped of nutrients. Likewise, overgrazing by animals can take a heavy toll on the plants of the savanna, offsetting the delicate balance between grasses and woody plants.

The Sahel Two women struggle through a monsooon during the wet season.

Northern Australia Large fires (shown as red dots) are a common feature of the grasslands of Australia.

SNAP BETTER

with VIVITAR Become the photojournalist you always wanted to be by taking the kind of shots you see in National Geographic with our cameras. You wonâ&#x20AC;&#x2122;t believe your eyes.

Career spotlight NG: Can you tell us a short history about Kruger National Park? Besmati: Well we were established in 1898 in the South African Lowveld. Today, the park encompasses nearly two million hectares, which I find extremely impressive. The land has been an important site of both wildlife and human development for centuries. You can even see bushman rock paintings in Masorini and Thulamela. NG: What do you think is the main mission of the park? Bestmati: You know that’s really interesting because many people think of Kruger Park and immediately picture luxurious vacation lodges. It’s true that we have people from all over the world come on vacation here, but our real focus is on conservation. We were established to protect the wildlife in the South African Lowveld. NG: In terms of conservation, what kind of issues do you encounter? Besmati: Kruger Park is considered a tropical savanna biome, so we have to deal with both man-made issues, such as fires, and naturally occurring issues, like flooding. Just like any other biome, there is a multitude of limiting factors that affect the success of organisms, and it is our job to lessen or prevent them through complex and widespread efforts. NG: I know you say the conservation efforts are complex, but can you give us some information on what they entail? Besmati: The main focus of our conservation work is to support the biodiversity of organisms within the Kruger National Park. You know, we have over 147 species of mammals and 337 species of trees, so there are huge amounts of life on this land. I personally think our most important conservation effort is population survey and management. We have rangers, such as me, who go out into the park to observe the wildlife living there. We take care to record the plants and animals we see, as well as the environmental conditions. NG: That seems like an extremely tedious process. Besmati: It can be tiresome, but I really enjoy it because it constitutes the most scientific aspect of my job. I get to test soil fertility and do scientific drawings of various organisms in my ranger diary. I am a trained environmental scientist, so it is awesome that I can combine my loves for science and wildlife in my career. NG: How exactly do these observations aide in conservation? Besmati: We cannot isolate problems with the park’s living organisms until we discover them. For instance, through our field surveys we can discover disease among a certain species or the invasion of an alien plant. This is where the manage-

Contributor Elizabeth Clarke sat down with Kruger Park ranger Paul Besmati to learn just what it takes to preserve some of the world’s most diverse land.

ment aspect of population survey and management comes into play. Once problems are discovered, we take extra measures to learn about their causes and prevent future occurrence. Just last week I participated in the widespread removal of a weed that had been introduced into the park by a farmer and was overpowering the native plant life. NG: What about the social aspect? Are there any conservation efforts that revolve around human connection and education? Besmati: Absolutely! Much of our conservation tactics emphasize continued education, both locally and globally. I have been a Kruger Park ranger for twenty-nine years, so much of my job involves training new rangers. I take new hires on tours around the park every year so they can become familiarized with the geography and wildlife. I sometimes teach safety classes for new rangers as well. I find the recruitment and training of new rangers extremely important because they are the most accessible advocates for the park. NG: Does Kruger Park have relationships with the local people and government? Besmati: We constantly try to influence economic legislation, either through public campaigns or private meetings. I find the politics overwhelming, but our main goal always remains the protection of wildlife. We also have a public relations team who educates local farmers on current legislation in order to ensure compliance with anti-poaching, development, and trespassing laws. This is extremely important to conservation because man-made fires and illegal human land development can be extremely detrimental to the park’s ecosystem. NG: What about tourism? Do you find it detrimental or helpful to conservation efforts? Besmati: On the weekends I normally lead safari tours, and I always come away feeling like I opened people’s eyes to the beauty of the African savanna. Many people come here looking for a relaxing, fun vacation, but they leave with a whole new perspective on the value of life, from bacteria to lions to humans. I would say that is the most rewarding part of my job, making a difference I mean. Because when it comes down to it, nature provides us with so much, and we need to protect it. NG: Thank you so much for talking to me. I really learned a lot. Besmati: It was my pleasure! For more information on Kruger National Park and African savanna conservation, see the link on the National Geographic website.

vegetation

visitation

The tropical savanna biome is not, by any means, a mild environment. Wild fires, infertile soil, and a long dry season are all common to the tropical savanna. Yet there is a vast abundance of plant life in the tropical savanna, this biodiversity in such extreme conditions is truly a marvel.

kangaroo paw

Anigozanthos rufus

Kangaroo paws are found in the tropical savannas of Australia. These eye-catching plants are endowed with hairy green flowers and red stems that can grow up to a meter high. The hairs on the flowers of this plant are actually part of its adaptation. They help in water retention (because of their ability to grow in a dry climate) and keep predators from eating the flowers because of their strange taste. The stem of the plant is yet another adaptation. It is very sturdy and is thus a perfect place for pollinators, such as birds, to perch on and drink the plantâ&#x20AC;&#x2122;s nectar.

umbrella thorn acacia Acacia tortilis

The Umbrella Thorn Acacia, with its gnarled branches, flat-topped crown, and black to gray bark, is possibly one of the most picturesque and famous trees known to the tropical savanna biome. This plant is abundant because it is extremely well adapted to the savanna environment. It has evolved a taproot, which can grow to be up to 115 feet in length, and another set of roots which spread over a wide area near the surface of the ground. This incredible system of roots allows the Acacia to reach water even in the midst of the tropical savannaâ&#x20AC;&#x2122;s dry season. The crown of the Umbrella Thorn has also evolved into a perfect umbrella like shape (hence its name), which helps to prevent water loss. This shape allows the small leaves of the tree to capture sunlight, and because of the leavesâ&#x20AC;&#x2122; small size they also conserve water. Finally, the Umbrella Thorn Acacia developed thorns that keep savanna animals from eating its leaves, flowers, and seed pods.

baobab tree

Adansonia digitata The Baobab Tree, found in the tropical savannas of African and India, developed small finger like clusters of leaves which help to conserve water in the harsh dry season of the tropical savanna. This amazing tree is equipped with a trunk that is incredibly well-adapted to its environment. The thick cork-like trunk both retains water (up to 120,000 litres) and is fire resistant. This helps to prevent the tree from dehydrating during the dry season, and prevents the Baobab from perishing in the not-so-uncommon wildfires of the savanna. Surprisingly, the Baobab is leafless for the nine dry months of the year in the tropical savanna, this helps to prevent water loss.

fire fern

Cycas armstrongii

Fire Ferns are well-adapted tropical savanna plants that are reminiscent of a palm tree in appearance. Found in the Australian tropical savanna, these plants have leaves, composed of smaller leaflets, which can grow up to four feet long and range from a semi-glossy green to a very glossy green. They are adapted well to the common fires in the Australian tropical savanna. The trunk of this plant is able to survive wild fires and with the coming of the wet season is able to re-sprout its foliage. This adaptation is very effective, as can be seen in the amazing abundance of the Fire Fern.

river bushwillow

Combretum erythrophyllum This 30-35 foot plant, found in the African tropical savanna, branches out at odd angles creating a thick crown. This plant is equipped with three inch long leaves and small cream colored flowers, and is extremely well adapted to the harsh environment of the tropical savanna. It is equipped with long tap roots to reach water during the dry season, and has a thick layer of bark to help protect against forest fires. Finally, to conserve water, the River Bushwillow drops its leaves during dry spells. The success of these adaptations can be seen in the abundance and wide spread distribution of this plant.

Bermuda grass

Cynodon dactylon

Bermuda Grass originated in the savannas of Africa and is decorated with gray- green blades of about 1 to 4 inches in length. Its purple stem can grow to be 1.3 feet in length. This grass is particularly well adapted to the droughts of tropical savannas. When there is not enough water the upper parts of the plant die but the plant as a whole keeps growing. This is due to Bermuda grassâ&#x20AC;&#x2122;s rhizomes, or underground horizontal stems. The plant is able to keep growing from its rhizomes even in the midst of a drought. Another adaptation of Bermuda Grass is its root system. This can grow up to 59 inches in depth during a drought, thus allowing the plant to reach water underground even when conditions are dry.

A Day

in the Life 30

Enter the world of some of the tropical savannaâ&#x20AC;&#x2122;s most crafty animals to see just how they make it through the day.

White Rhino Where they are found: Africa

Ceratotherium simum

White rhinos are creatures of habit that frequently stay within a home range throughout their lives. They often travel to the same watering hole daily. Rhinos stay cool by lying in the shade or rolling in mud, which acts as a natural sunscreen. With enormous heads and square lips, white rhinos are equipped for eating grasses low to the ground. They often graze in communities of up to twelve

individuals. Though their eyesight is lacking, rhinos have a keen sense of smell that helps them to locate danger, food, and other rhinos. Both male and female rhinos are equipped with two horns used to fight attackers or protect their young. Rhinos stay with their mothers for about three years then become independent. In addition to that with their young, rhinos are known for their relationship with oxpeckers, which eat the ticks from their skin and warn them of danger.

Cheetah Acinonyx jubatus

Where they are found: eastern and southwestern Africa

savanna.

Cheetahs only need one drink of water every three Cheetahs are active hunters during the day. They

to four days, which becomes extremely helpful in

are the fastest land animals on the planet, capable

the dry season. They have a spotted coat that

of reaching 60mph in three seconds. What they

helps them stay hidden in grasses and shrubs.

lack in pure strength, they make up for in speed, using short sprinting bursts to hunt down mid-sized

Female cheetahs give birth to three or four cubs at

prey. Cheetahs implement their amazing eyesight

a time. The cubs stay with their mothers for over a

to spot prey hidden in the tall grasses of the

year, learning the valuable keys to survival.

Emu

Dromains novaehollandiae

Where they are found: Australia

them from getting over-heated during the day and cold during the night. They are also competent

Growing to an average of six feet tall, emus are

swimmers, which enables them to survive when

the largest birds in Australia. Interestingly, they

their habitat is flooded.

have wings but are unable to fly. Instead, emus

In terms of diet, emus prefer to eat fruit, flowers,

rely on their speed for evading danger. Emus have

seeds, green plants, and insects. They are

three toes that enable them to run fast and quickly

nomadic animals, so they frequently move to

change direction.

different food sources in times of drought. They can store extra fat, which comes in handy when

Emus have loosely packed feathers that keep

food is scarce.

Black Mamba Dendroaspis polylepis

Where they are found: South Africa

Active during the day, the snakes tend to stay in low, open areas, but sometimes warm themselves in trees. They feed off of small animals, such as rats, mice, squirrels, and birds. The snakes are equipped with highly toxic venom that kills their prey in a few seconds, and can kill a human in under an hour. This adaptation makes the black mamba virtually untouchable in terms of predators. Black mambas are feared for their aggressive behavior, but they prefer to evade conflict instead

of fight. When threatened, the snake will raise its head a few feet off the ground and spread out its hood. The female snakes lay 15-25 eggs which are often hidden in termite mounds to protect from predators. Once born, the baby snakes are completely independent. Black mambas spend the night sleeping in hollow trees, rock crevices, burrows, or empty termite mounds. They often return to the same place every night.

Nile Crocodile Where they are found: Africa

Crocodylus niloticus

Nile crocodiles are frequently found in the rivers,

swamps, and lakes of the tropical savanna. They can grow to be over five meters long.

crocodiles often hide underwater with their eyes

and nose barely visible above they surface. They

are masters of surprise, ambushing their prey with incredible stealth and strength then dragging it beneath the surface until it drowns.

The crocodiles often dig dens underwater to keep

Unlike most reptiles, Nile crocodiles are fiercely

of eating most animals, including turtles, birds, big

crocs protect their nests with diligence. Some

cool in the high temperatures. They are capable cats, and even humans if the opportunity arises. With their dark green skin and long snouts, the

protective parents. Both the mother and father

crocodiles even roll their eggs inside their mouths to help them hatch.

Giraffe Where they are found: Africa

Giraffa camelopardalis

Giraffes live in loosely organized herds without designated leaders. Though they are generally not

As the tallest animal on the planet, the giraffe is

territorial, males do establish dominance by swing-

uniquely equipped for reaching the top leaves of

ing their necks at other males. Young giraffes

acacia trees. Since this vegetation is inacces-

are mostly independent from their mothers at six

sible to other herbivores, giraffes have a huge

months, but only about one quarter of giraffes sur-

advantage when it comes to feeding. Giraffes can

vive their first year due to predators. In contrast,

survive in areas with little water, and they also eat

carnivores rarely hunt adult giraffes because of

grasses and fruits when necessary. Their bodies

their huge size.

have extremely elastic blood vessels and special valves that help prevent the build-up of blood and fainting when they move their heads.

African Elephant the

The race is on to save the African elephant, whose speciesâ&#x20AC;&#x2122; status has become threatened. Poachers hunt the gentle giant for its beautiful ivory tusks, which are valuable on the black market. 39

The African savanna is home to the earth’s largest land mammal: the African elephant. These gentle giants can grow to be 13 feet high, weighing up to 14,000 pounds and have a life span for up to 70 years. Yep, that’s just about as long as most humans’ lives. While the lives of these beautiful animals are just as precious as humans’, poachers continue to hunt the animal for its ivory tusk and the animal has become threatened. African elephants are found scattered throughout the savanna zones of 37 countries south of the African savanna. These include Kenya, Botswana, Zimbabwe, Namibia, and South Africa. In 1979, there were 1.3 million African elephants inhabiting the grasslands of Africa. In 1987, researchers counted an estimate of 600,000 elephants roaming the savanna. Poachers had begun to rigorously hunt the animals for their prized ivory tusks. After slaughtering the animal’s head, the ivory tusks are then sold on the black market to be made into billiard balls, piano keys, knife handles, or used in medicinal cures. Despite efforts in 1989 to protect the elephants, researchers have recently found that a high percentage of single adult female families had an atypically small family size. This, along with findings that 30% of all adult females in Mikumi National Park were solitary, has shown that there has been little change since the eighties and these statistics have remained basically the same. Elephants are also being affected by humans because of the loss of their habitat. Humans continue to develop land that the African elephants inhabit, forcing them to migrate to other areas. Elephants may not be able to access water as well in other locations and also suffer from the threat of malnutrition as land is developed and their vegetation disappears. Both male and female elephants use the tusks themselves as elongated incisors, just as we use our teeth. Tusks are made of dentine with an outer layer of enamel and never stop growing. The largest tusks are found on old bulls, which are the most targeted elephants for poachers because of the size of their tusks. 40

Tusks can be used for defense, battle, lifting, digging, and stripping bark. Rarely will an elephant need to defend itself against predators using its tusks, but bulls often battle each other to assert dominance in within a herd. Elephants also use tusks for day-to-day tasks of survival and foraging for food. The habitat of the African elephant is the grassland or savanna. Elephants will migrate to locations close to water to remain hydrated, but the herds also strive to distance themselves from human populations in order to minimize contact with humans. While the African elephant needs huge quantities of water to survive, it also combats the dry, hot climate of the grasslands in several ways. One of which is the large, fanlike ears that differentiate African from Asian elephants. The ears on an African elephant radiate heat and help to disperse warmth out of the head and keep the animal cool. The elephant also uses its ears to fan the rest of its body. Not only are the ears of the elephant used to keep it cool, but the elephants also have acute hearing, used in defense against predators. The elephants also have adapted their huge skulls by developing large sinuses to minimize weight and keep the animal balanced. It’s also believed that the highly developed sense of smell in the trunk is used to locate water by sensing it underneath the earth. Their skin is actually very sensitive to sunburn and bug bites so the elephants often roll in dirt or mud to prevent irritation. The niche of the African elephant is thought to be the role of stripping the bark off of trees to defoliate areas. The elephant does this with its powerful trunk. Elephants are very social animals and remain in families, which make up herds. When a member of a herd dies, the elephants of the herd will often mourn for days on end. They will also fondle the tusks and bones of dead elephants. While elephants are known to be social animals, researchers have recently found that some families of African elephants in Mikumi National Park consist entirely of nonkin members. This is thought to be due to

continued poaching of the species. It was also consistent with the predictions of the researchers of long-term impacts on the species due to poaching. The same researchers also looked at stress levels in the elephants. Stress levels were found to be highest in the groups without an old bull that leads and protects the herd. As previously mentioned, these matriarchs are the most commonly targeted group of elephants. Herds nearest to villages and farthest from park headquarters (where they are more easily protected) also had high levels of stress. The high stress levels disrupt female fertility, resulting in fewer calves and lower populations. Although little has changed since the 1980â&#x20AC;&#x2122;s, this group of researchers also found that the number of elephant families with tusked old matriarchs has increased by 14.2% since then. Conservation efforts for the African elephant are in full effect. The African Elephant Conservation Act of 1989 was passed to discourage the trade of elephant ivory in the

US. Even though this was a long time ago, the sale of ivory on the black market still exists. Conservation trusts like the African Wildlife Foundation and the African Elephant Conservation trusts continue to work to protect the animal and monitor the progress of the revival of the species. Programs like these work to increase public awareness of the dangers of poaching and fund scientific research, training, and advocacy of the species. Elephant conservations and education programs are also provided by organizations like the International Elephant Foundation, which works to manage protected strongholds and zones in natural habitats of African Elephants. Donate to these programs today and find out more about the African elephant at www.ngm. com. -- Skye Harnsberger

Meet the neighbors Food web LION

VULTURE

TERTIARY

SECONDARY

WILD DOG

HYENA

SECONDARY

CARACAL

EAGLE

SECONDARY

SERVAL

SECONDARY

CHEETAH SECONDARY

TERMITE PRIMARY

ANT

WILDEBEEST GAZELLE PRIMARY PRIMARY

GRASSHOPPER

IMPALA

PRIMARY

HARES

PRIMARY

RED OAT PRODUCER

ACACIA PRODUCER

Parasitism is a form of relationship between organisms in which the parasite benefits at the expense of the hosting organism. Some species of grass fly, for example, are parasites.They feed on the lacrimal secretions (fluid that lubricates the surface of the eyeball) of animals. Another parasitic relationship in the tropical savanna is that between bot flies of the genus Gyrostigma and rhinoceroses. These flies develop in the in the stomach of rhinos, and in their larval stage prey on rhinos. Commensalism is a form of relationship between organisms in which one organism benefits off of another, and the other organism is not affected. One example of commensalism is the relationship between hyenas and lions. Hyenas feed off of the remnants of a lion’s kill, and thus benefit from the lion. But the hyena’s feeding does not affect the lion, because it has already finished its meal. This form of relationship also occurs between vultures and lions. Vultures, similarly to hyenas, feed on a lion’s kill after the lion has finished feeding. This benefits the vulture and does not harm the lion. Mutualism is a symbiotic interaction between two a nimals. This form of relationship is mutually beneficial. One incredible example of this type of relationship in the tropical savanna is between ants and the Acacia tree. The tree produces sweat secretions which the ants feed on, and in return the ants attack insects which feed on the vegetative tissue of the tree.

STAR GRASS PRODUCER

They will not, however, attack potentially pollinating insects. Another more famous example of a mutualistic relationship in the tropical savanna is that between rhinos and oxpeckers (a kind of bird). The oxpecker eats bugs and ticks off of the rhino, and the rhino provides protection for the oxpeckers. Competition in biology is a contest between organisms (or groups of organisms) for resources, territory, or mates. This relationship between animals occurs quite often in the tropical savanna. For instance, during a drought many animals compete for access to a water hole. Likewise, scavengers often compete over carcasses. For example, vultures will fight over a gazelle’s body. Predation is the most common type of relationship within an ecosystem. Predation is simply the relationship between a predator and its prey. The predator (the organism that hunts) feeds on its prey (the organism that is attacked). Examples of predation are shown in the above food web. For example, a gazelle is prey to a caracal, wild dog, and hyena, who are predators. However, a caracal can become prey to a lion, the ultimate predator of the savanna.

Inspiring people to care about the planet

NATIONAL GEOGRAPHIC

RAPH G O E

Works Cited

N AT I O N

The National Geographic Society is chartered Swarthmore-Wallingford, PA as a nonprofit scientific and educational organization “for the increase and diffusion of geographic knowledge.”

Credits

“Animals.” National Geographic. National Geographic Society, 2012. Web. 22 Apr. 2012. <http://animals.nationalgeographic.com/ animals/?source=NavAniHome>.

ARTICLE AUTHORS: Elizabeth Clarke, Maddy Goodwin, Skye Harnsberger

B., Celeste. “Australian Savanna Plants.” Blue Planet Biomes. Web. 24 Apr. 2012. <http://www.blueplanetbiomes.org/savanna_australiaplant_ page.htm>.

GRAPHIC DESIGNER: Skye Harnsberger

Charles Darwin University, and Faculty of engineering, science, health, and the environment. “Major threats to savanna ecosystems.” learnline. cdu. Charles Darwin University, 2012. Web. 9 Apr. 2012. <http:// learnline.cdu.edu.au/units/sbi507/index.html>.

INSPIRATION: The National Geographic

“Culture of the Maasai.” Maji Moto Eco Camp. Eyes on Africa Safaris Ltd., 2012. Web. 24 Apr. 2012. <http://www.majimotocamp.com/index. php/28-the-camp/activities/70-culture-of-the-masai>.

We would like to thank our second block AP

“Earth Floor: Biomes.” Cotf. Wheeling Jesuit University/NASA-supported Classroom of the Future, 1997-2004. Web. 24 Apr. 2012. <http:// www.cotf.edu/ete/modules/msese/earthsysflr/savannahP.html>.

block). Thank you also goes to the librarians

“Effects of Poaching on African Elephants.” Center for Conservation Biology. University of Washington, 2009. Web. 24 Apr. 2012. <http://conser vationbiology.net/>.

you to our parents for helping us pay to get

“Elephant Tusks.” EleAid. EleAid, 2003. Web. 24 Apr. 2012. <http://www. eleaid.com>.

Society Magazine

Biology class for being the greatest AP Bio class out there (way better than first or second for letting Skye look at past issues of National Geographics for inspiration. Another thank

F I C IA L A . D. 2

this magazine printed nicely. Finally, we would also like to give a big shoutout to the greatest

2 1 0

biology teacher ever, Ms. Shepard. Thanks for all you do for us Shep!

“Kruger National Park .” sanparks.org. South African National Parks, n.d. Web. 24 Apr. 2012. <http://celtis.sanparks.org/parks/kruger/camps/ olifants/default.php>. O’Donnell, Kate, Peter Jacklyn, and Emma Woodward. Savanna Explorer. N.p., 2010. Web. 17 Apr. 2012. <http://savanna.org.au/all/faq/. “Oxisols Home.” Soil Science Division. Web. 24 Apr. 2012. <http://soils.cals. uidaho.edu/soilorders/oxisols.htm>. “People of the Savanna.” Arlington Heights School District 25. Africa Focus, 2000. Web. 24 Apr. 2012. <http://www.ahsd25.k12.il.us/curriculum/ africa/svpeople.htm>. “Savanna Explorer - All Regions - Savanna People - Industries & Employment.” Savanna Explorer. Web. 24 Apr. 2012. <http://www. savanna.org.au/all/industries2.html>. “SOILS or You Are In A World Of Dirt.” Web. 24 Apr. 2012. <http://geography. unt.edu/~maxey/PhysicalGeology1610/1601PDF/Soils_Geology. pdf>. Thirteen. “The Vanishing Lions.” PBS.org. Educational Broadcasting Corpo ration, 2012. Web. 12 Apr. 2012. “Tropical Savanna.” The WIld Classroom. N.p., 2003. Web. 9 Apr. 2012. <http://www.thewildclassroom.com/biomes/tropicalsavanna.html>. West Tisbury Elementary School. “Savanna.” Blue Planet Biome. Brynn Schaffner, 2010. Web. 9 Apr. 2012. <http://www.blueplanetbiomes. org/index.htm>. 43

This is Imani. She needs your help in raising money to fund efforts to take back land that the African government has taken from her people, the Maasai. The beautiful jewelry she and her family make can be yours and also fully benefits the efforts in her region. Donations are also welcome. Will you help her?

Maasai Jewelery

100% of profits go towards relief efforts in the Massai tribal regions of Tanzania & Kenya. www.massaitribaljewelery.org