Africa's vanishing apes: these forest-dwelling animals are losing their land--and their lives.
People have cleared much of the forested land in Africa (see map, p. 8). That has caused chimpanzees to disappear along with many closely related African primates. Topping that list are Eastern Gorillas (Gorilla beringei, guhRIH-luh bah-RING-gay), Western Gorillas (Gorilla gorilla), and Bonobos or Pygmy Ctumpanzees (Pan paniscus, PAN PAN-iss-kuss). These great apes, a group of long-armed and tailless animals that also includes orangutans from Asia, are the animals most closely related to humans. But each of these ape species is endangered (in danger of dying out). The top reason: human-caused habitat loss. Hoping to keep gorillas and chimps from disappearing, scientists like Stratford are studying the great apes to find out how they are affected by their shrinking habitat.
"Habitat loss is by far the worst threat facing these animals," says Alexander Harcourt, a primatologist at the University of California, Davis. In Sierra Leone--a West African country where chimps live--80 percent of forest lands disappeared between 1980 and 1995. "It's still going fast. The West African chimps don't have much longer [before they could be homeless and die out]," adds Harcourt.
A study published by the United Nations in 2002 emphasizes apes' dim-future. It predicts that by 2030 only 10 percent of Africa's forests will remain undisturbed. Why? Africa's human population is growing. And civil war and unrest in countries such as the Democratic Republic of the Congo have forced millions of people to flee their homes. Many families move into the forest. There, they cut down trees for firewood or to create farmland. Also, logging companies deforest (cut down and remove trees) vast areas of ape habitat to collect wood to sell.
FOREST OF FOOD
That spells trouble for hungry apes. Without their forest habitat, the animals may starve. "Gorillas can't live outside the forest," Harcourt says. "They're big animals. They need a lot of food, a lot of foliage (leaves)." A single gorilla devours about 18 kilograms (40 pounds) of leaves a day from plants growing on the forest floor. They also climb trees to snag figs and other fruits. Over the course of a year, a group of gorillas may roam up to 18 square kilometers (7 square miles) of forest in search of food.
Like gorillas, chimps snack on fruit as well as leaves and nuts. "Chimps know the location of thousands of fruit trees in the forest, the way you might know your local supermarket," says Stanford. But chimpanzees are more varied munchers than gorillas. For instance, chimps snack on insects that they gather by threading a long stem of grass into a termite nest. When the chimp pulls out the stem, it's covered with tasty termites. Chimps are also predators--they kill monkeys and small animals for food.
The chimps' willingness to chomp on a wide assortment of food means they can make do in more varied habitats. Although most chimps live in tropical forests where food is plentiful, some survive in tree-studded grasslands. This makes them less vulnerable to forest destruction than gorillas.
NOWHERE TO HIDE
When forests vanish, apes lose not only vital food but also protection. At night, chimps, as well as female and young gorillas, nestle into trees to sleep. They build lofty nests in the branches--out of reach of predators such as leopards. Here, the apes can snooze without becoming cat food.
But the biggest threat comes from humans. Logging companies build roads into the heart of the forest, says Harcourt. That makes apes easy targets for poachers (illegal hunters). The hunters kill the animals for bush-meat (meat from wild animals), which they eat or sell in local markets.
When forests were larger and undisturbed, it was more difficult for poachers to travel into them to get bushmeat. Now, road access means that apes are killed more frequently. "You can protect a forest, but if there's one logging road going through the middle, then commercial hunters can kill all the apes," says Stanford.
Disappearing forests also make apes more vulnerable to disease. As humans build logging roads and develop farmland, what habitat remains becomes fragmented (broken into smaller, unconnected pieces). Squeezed into closer quarters, chimps and gorillas are more likely to get sick. "There's not enough food and that weakens them," says Harcourt. Plus, because the animals are packed in tighter, sicknesses spread more easily through a population.
Forest fragmentation also brings apes into closer contact with people--and the diseases that humans carry. A flu that might sicken a human for a few days can wipe out a whole population of chimps.
SAVING GREAT APES
What can be done to save the great apes? Environmental groups have worked to protect land from human development. "A number of African countries have set aside land for [protected] parks," says Harcourt. There. laws are in place to help keep apes safe from human threats.
An added incentive for protecting the apes: It safeguards other species in the ape's ecosystem (system of interactions between forms of life). "Gorillas and chimps are umbrella species," says Stanford. "If you protect them, by definition you're protecting their habitat and a whole host of other animals that live there."
Another reason for humans to help the great apes survive: "These guys are closely related to us." says Harcourt. "They're a living link with the rest of the animal world."
Nuts & Bolts
Primates are an order, or classification, of organisms that includes monkeys, apes such as chimpanzees and gorillas, and humans. Primates have highly developed brains and almost always live in large social groups. Most primate species spend at least part of their lives in trees. For a strong climbing grip, they have developed thumbs that can be moved independently from the rest of their fingers. Because of hunting and human-caused habitat destruction, many primate species are endangered.
It's Your Choice
1 Which of the following is NOT true about great apes?
A They are the animals most closely related to humans,
B All great apes have tails,
C Great apes are endangered.
D They are primates.
2 What is one reason that gorillas need the forest?
A It provides shelter from tropical hurricanes.
B A gorilla can devour t8 kilograms (40 pounds) of leaves a day.
C Gorillas hunt forest animals.
D No other primates live there.
3 Fragmented forests are woodlands that are
A broken into small, unconnected areas.
B good habitat for apes.
C created by humans to help save chimps and gorillas.
D not found in Africa.
IT'S YOUR CHOICE, p. 11 1. b 2. b 3. a
DID YOU KNOW?
* Gorillas are the world's largest living primates. An adult male---generally about twice as large as an adult female--can weigh up to 210 kilograms (460 pounds) and stand up to 1.8 meters (6 feet) tall. Despite their formidable size, gorillas are usually peaceful animals, unless provoked.
* Chimpanzees, bonobos, and humans share at least 98 percent of the same genes. Bonobos and chimps are more closely related to humans than they are to gorillas.
* Poverty and wars have forced many people in Africa to use--and often destroy--ape habitat. How can a balance be found between meeting the needs of these people and saving the great apes? Discuss as a class.
Geography: Research one of the countries in which orangutans live in the wild. How are human pressures on animals in this region similar to those on primates in African countries?
* "Fifi Fights Back," by Jane Goodall, National Geographic, April 2003.
* To learn more about gorillas' forest habitat, visit: http://congogorillaforest.coml
DIRECTIONS: On a separate piece of paper, answer the following questions in complete sentences.
1. Why is the forest habitat of Africa's great apes rapidly vanishing?
2. How are vanishing forests putting chimps and gorillas at risk of predators?
3. How are disappearing forests making apes more vulnerable to diseases?
4. What has been done to help save the great apes?
1. The great ape's forest habitat is rapidly diminishing because logging companies deforest vast areas to collect wood to sell. Also, civil unrest in some African countries and a booming human population in Africa have forced millions of people to move into the forest. There, they cut down trees for firewood or to create farms.
2. Vanishing forests put chimps and gorillas at risk of predators because chimps, as well as infant and female gorillas, sleep in trees at night, They make lofty nests in branches, where they steep out of reach of predators like leopards, Also, when logging companies build roads into the forest it is easier for poachers-human predators--to hunt apes for bushmeat, which they eat or sell in the markets
3. Disappearing forests create fragmented habitats, leading chimps and gorillas to live in tighter quarters. Food becomes scarce, and the animals become weak and get sick. When packed closely together, sickness can spread easily through an ape population, in addition, forest fragmentation brings apes closer to humans This makes it easier for apes to catch human diseases. These foreign diseases could wipe out ape populations.
4. To help save the great apes, environmental groups are working to protect land from human development. Also, many African countries have set aside land for protected parks. There, laws help keep apes safe from human threats.
In "Africa's Vanishing Apes" (p. 8) you saw photos of chimps using tools. Complete the two following activities to learn more about this behavior.
1. THUMB TALENT
Predict: Can primates survive without opposable thumbs (thumbs that can be placed opposite the fingers)?
You need: masking tape
Set up: Use masking tape to stick your thumbs to the sides of your hands.
Task: Try to pick up a book, pull up your socks, or untie your shoelaces.
1. Did you have trouble performing these tasks?
2. Can you survive without opposable thumbs?
3. Chimps also have opposable thumbs. How does this feature help wild chimps survive? (For more on chimps' physical features, visit: www.janegoodall,org/chimp_central/ chimpanzees/physical-characteristics.asp)
2. TOOLIN' AROUND
Purpose: Experience how chimps use tools in the wild.
Instructions: You will select materials in "Forest Tool Box" (see below, right) to create a tool to complete the challenge below.
You need: sand (1.5 liters, or 6 cups) * 2-liter soda bottle with the top quarter cut off * 20 small paper clips
Set up: Pour the sand into the soda bottle. Mix the paper clips into the sand, until they are hidden.
Task: Create a tool and use it to collect five paper clips.
1. What kinds of materials did you choose to create your tool?
2. How did the challenge relate to wild chimps? (For more on chimps and tool use, visit: http://nationalzoo.si.edu/Animals/ThinkTank/ ToolUse/ChimpToolUse/default.cfm)
Forest Tool Box
masking tape * pipe cleaners * small magnets * rulers * pencils * drinking straws * cotton balls * washers * clothespius
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|Title Annotation:||Life endangered species|
|Date:||Jan 3, 2005|
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