Through play, kids learn how to get along.

“Through play, youngsters of all ages learn the rules of social conduct,” says Marc Bekoff. He’s an animal behaviorist at the University of Colorado in Boulder. Bekoff has spent years studying similarities between play behavior in animals and play behavior in people.

“The things I see in captive animals, I see in wild animals and in kids all the time,” he says.

By studying how animals interact with each other, especially during play, Bekoff and other researchers are discovering a sense of fairness in a wide range of creatures, from coyotes to monkeys to birds.

The research may help explain how people learn to play fair. And, while scientists have traditionally favored the idea that competition determines how animals behave, the new work suggests that cooperation deserves just as much attention.

Serious play

Play, as Bekoff puts it, is a serious business.

When they push each other around, animals get exercise. They develop skills, such as hunting and mating. Some studies even suggest that playing more leads to bigger brains that are better at reasoning and learning.

Through play, animals find limits, such as how hard they can hit one another before their playmates get upset. And they learn how to apologize, forgive, and trust each other, just like kids do.

“Animals have to negotiate fairness,” Bekoff says. “If I cheat you, others won’t play with me. If Johnny sees Harry beat up Mary, nobody’s going to play with Harry.”

Like dogs, coyotes use play to develop hunting skills. Play also allows the animals to explore social situations and develop the behavior necessary to be a member of a social group.

R.H. Barrett, U.S. Fish and Wildlife Service

Bekoff has been studying wolves, coyotes, and dogs for more than 15 years. To anyone who has ever watched a pile of squirming puppies, he says, it may seem obvious that they play.

The furry tykes roll around and swat each other. Usually, they look like they’re having a rollicking good time until one pushes another too far and someone skulks away. Because people tend to read too much into animal behavior, though, scientists can’t rely on such stories alone.

Instead, Bekoff has turned to videotape. He and his colleagues have developed a set of about 60 coded terms to describe the puppy behavior they see, including bites to different parts of the body, pawing, body slamming, shoving, head shaking, and standing over another animal’s back.

The researchers film groups of animals interacting with each other. They name each animal and note which ones are more dominant. Then, they play the videos back over and over again. As they watch, the scientists write down the codes for all the behaviors they see.

“I’ve discovered that if I don’t account for what the animals are doing every tenth of a second, I lose information,” Bekoff says. “One of the things my studies have done is to caution people that they really need to pay attention to details.”

Interesting patterns

The details have revealed some interesting patterns about the behavior of both wild and captive animals.

Play is an important part of a dog’s life.

Public Health Image Library

A behavior called “play bow,” for one, seems to be especially important. When a dog crouches on the ground with its rear end in the air, it’s saying, “I want to play with you,” Bekoff says. His research shows that wolves, coyotes, and dogs use play bows directly before or after behaviors that could be taken the wrong way.

If one animal gives another a particularly hard or aggressive bite, for example, the two normally part ways. If the biter uses a bow, though, either as a warning or as an apology, play immediately continues.

As another way to maintain fair play, Bekoff has found, animals sometimes refrain from swatting or biting as hard as they can, especially when they are playing with a weaker companion.

Other times, two animals play role-reversal games. The weak act strong, and the strong act weak. Along with play bows, these types of behaviors act like punctuation in a sentence, Bekoff says. Each one is a signal about what’s coming next.

Cooperation

Researchers are finding evidence of fair play in hyenas, bears, and other animals. Ravens seem to engage in cooperative play, chasing each other back and forth. Even rats change their behavior to maintain play.

Ravens appear to engage in cooperative play, chasing each other back and forth.

Gary M. Stolz, U.S. Fish and Wildlife Service

For social animals, learning to cooperate and work together is a matter of survival, Bekoff says.

In a 7-year study in Wyoming’s Grand Teton National Park, Bekoff found that coyote pups that don’t play develop fewer social bonds and are more likely to leave the group.

Odds aren’t good for these independent types. Many of them die sooner than those who stay close to home. Bekoff has found that coyote packs are better than individuals at scaring away threatening intruders.

Bekoff would expect to see similar patterns of play and cooperation in most social animals. In contrast, animals such as wolverines would be less likely to practice fairness in play because they spend most of their time living and hunting alone.

Monkey business

Studies have long suggested that monkeys and apes have a strong sense of what’s OK and what’s not. In 1964, for example, researchers showed that hungry rhesus monkeys will refuse food if eating it causes another monkey to get an electric shock. (Rats actually behave the same way.)

More recently, researchers Sarah Brosnan and Frans de Waal of the Yerkes National Primate Research Center in Atlanta showed that brown capuchin monkeys know when they’re being cheated. (See “No Fair: Monkey Sees, Doesn’t” at http://sciencenewsforkids.org/articles/20030924/Note3.asp .)

Capuchin monkeys demand a fair deal.

Frans de Waal

The monkeys learned to give tokens to the researchers in exchange for food. At first, both monkeys of a pair received grapes in exchange for tokens. Each monkey watched the other’s exchanges. Once the animals learned the drill, the scientists started giving cucumbers instead of grapes to one of the two monkeys. Monkeys don’t like cucumbers nearly as much as they enjoy grapes.

After a while, the cheated monkey grew disgruntled. In 10 out of 25 trials, it either rejected the cucumber or refused to trade. When Brosnan offered a grape to one monkey without even asking for payment, the shortchanged monkey refused to trade 20 out of 25 times.

Nothing to lose

As important as cooperation is, conflict will always be a fact of life for both animals and people. And that’s not necessarily a bad thing. Plenty of friendships are built on a healthy spirit of rivalry. Competition can be inspiring. Even a little bit of teasing can make you feel included.

Play has an important role in bringing a sense of fairness into such conflict. It also provides practice for dealing with all sorts of situations that can come up in daily life.

The great thing about play, Bekoff says, is that you’ve got nothing to lose. As long as you know when to say when, you’ll get along just fine.

Going Deeper:

Word Find: Fair Play

Additional Information

Questions about the Article

Until now, all the digging has happened only in Earth’s outer layer, called the crust. Oil and gas wells normally go no deeper than about 6 kilometers. A new study shows that natural gas, mainly methane, may also form in a much deeper layer called the mantle. This means that new sources of energy could lie at depths of 100 kilometers (62 miles) or more.

During a simulation of the conditions in Earth’s mantle, this bubble of methane formed when researchers mixed iron oxide, calcite, and water at high temperatures and pressures.

PNAS

Oil and gas found near Earth’s surface are often described as fossil fuels. Most scientists favor the idea that these hydrocarbon fuels were formed by the breakdown of ancient plants and animals. However, recent research also shows that methane gas can form in the crust when there are no living creatures around.

Researchers from Indiana University South Bend wondered if this could also happen deeper down. So they did a lab experiment to simulate conditions in the mantle. They combined materials normally found at those depths. Then they put the mixture under extreme heat and pressure.

The experiment produced tiny bubbles of methane gas, the scientists report. However, no one knows yet how much methane, if any, is actually present in the mantle. And, if it is present, whether any gas might seep up into the crust and emerge from spots on the ocean floor.

The research could provide important clues about how life began on Earth. Some bacteria feed on methane. If methane were present in the mantle, it could support populations of microbes, allowing them to survive in such an extreme environment. It may also be worth looking for underground stores of methane on Mars and other planets when searching for signs of life.—E. Sohn

Going Deeper:

Goho, Alexandra. 2004. Deep squeeze: Experiments point to methane in Earth’s mantle. Science News 166(Sept. 25):198. Available at http://www.sciencenews.org/articles/20040925/fob7.asp .

Information about the origin of fossil fuels can be found at www.all-science-fair-projects.com/
science_fair_projects_encyclopedia/Fossil_fuel (Science Fair Projects Encyclopedia).

Recently discovered fossils suggest that a prehistoric sea creature with such a snakelike neck could have sucked in prey. It’s the first example of this kind of feeding strategy ever discovered in an ancient water-dwelling animal.

The fossilized neck bones of this ancient, long-necked sea creature suggest that the animal, at least 3 meters long, captured its prey by creating water suction as it struck.

C. Cain/AAAS, Science

The creature, called Dinocephalosaurus orientalis, lived in southern China 230 million years ago. It belonged to a group of prehistoric animals known as protorosaurs, and it probably spent most of its time in shallow water near coastlines.

Dinocephalosaurus orientalis means “terrible-headed lizard from the Orient.” Fossils show that its shape was as intimidating as its name. Although the beast’s body was less than 1 meter (3.3 feet) long, its neck stretched a full 1.7 meters (5.6 feet). The neck had 25 long vertebrae and additional bones, which look like ribs, that were attached to the vertebrae.

To explain the weird neck structure, researchers from the University of Chicago and Beijing propose that the lizard’s neck ribs helped it hunt. When the animal thrust its head forward to snap up prey, muscles in its neck contracted. That would make the neck bones spread out and the throat get bigger. This action would create suction that would slurp up water and prey into the creature’s mouth.

Some modern water animals, such as snapping turtles and other reptiles, use suction in their mouths to catch prey. The terrible-headed lizard’s suction would have been much more powerful. And much more terrible, too.—E. Sohn

Going Deeper:

Perkins, Sid. 2004. Big gulp? Neck ribs may have given aquatic beast unique feeding style. Science News 166(Sept. 25):195. Available at http://www.sciencenews.org/articles/20040925/fob1.asp .

You can learn more about protorosaurs, which are not considered to be dinosaurs, at www.dinoworld.net/tany.htm (Dinosaur World).

At about the same time, a series of typhoons killed at least 40 people in the Philippines and forced more than a million people to flee. Three weeks later, Hurricane Frances followed Charley’s lead, again pummeling Florida—to the dismay of many people in the state. Then came Ivan and Jeanne. Hurricane Jeanne killed more than 1,000 people in Haiti, before heading for the Bahamas and Florida.

This satellite image shows Hurricane Charley near the time when the storm’s center, or eye, reached the west coast of Florida at Cayo Costa on Aug. 13, 2004.

National Oceanic and Atmospheric Administration

The onslaughts may have been massive, but they weren’t a surprise.

Every year, major storms cause major problems around the world. There’s nothing people can do to stop the powerful forces of nature. But new techniques are helping scientists to predict how, when, and where the big ones will occur. The more accurately scientists can give warnings, the more likely people are to grab their valuables and flee to safety.

Predictions are improving. “We’ve gotten better over the years, especially the last few years,” says Phil Klotzback. He’s an atmospheric scientist at Colorado State University in Fort Collins.

Storm formation

There’s plenty left to learn, though. Even when scientists can figure out where a storm is headed, winds can change at the last minute, carrying the storm in a new direction.

Charley, for example, was originally headed right for the city of Tampa Bay but ended up hitting the Florida coast further south.

Hurricane-driven waves strike a sea wall.

NOAA Photo Library

“A little shift can make a big difference,” says meteorologist Eric Blake. He works at the National Hurricane Center in Miami. “Meteorology is both a science and an art.”

The science part depends mostly on computer simulations, or models, and knowledge of the past. Scientists have been collecting data about storms for decades. They’ve noticed patterns that suggest what it takes for a strong storm to form in the first place.

Hurricanes that hit the United States start when a thunderstorm forms off the coast of Africa. Storms also develop over tropical waters in other parts of the world. Most storms end up falling apart on their own, and we never hear about them.

For a hurricane to get organized, “conditions have to be just right,” Klotzbach says.

First, the ocean water needs to be warm enough so that the winds can take up water through evaporation, which rises into the air. As it rises, the vapor cools and turns back into liquid. This process releases heat. The cycle of evaporation and condensation is like an engine that causes winds to swirl and grow. It drives the formation of a hurricane.

If wind speeds inside the swirling mass reach 40 miles per hour, the system is classified as a “tropical storm,” and it gets a name. At 75 miles per hour, it becomes a hurricane. In the western Pacific, hurricanes are known as typhoons.

On average, 60 or 70 storms form off Africa every year, Klotzbach says. About 10 of them get names. There are usually about six hurricanes. Two tend to be very intense, with winds of 115 miles per hour or higher.

Hurricane season lasts from June 1 to Nov. 30. Ninety percent of all hurricanes hit in August, September, and October, Klotzbach says. Half usually happen in September, when conditions are most favorable.

Hurricane tracks

The National Hurricane Center tracks storms as they happen. Observations and data come from people on ships out at sea and from satellites in orbit around Earth. Computers crunch the data for warning signs of a developing storm.

Years of observations have supplied scientists with fairly reliable patterns that help them figure out what’s going to happen next.

Experts try to predict where a hurricane will go. Here, they show Hurricane Charley’s possible track after the huge storm hit the Florida coast.

NOAA

In the northern hemisphere, hurricanes spin counterclockwise around a center, called an eye. Tropical trade winds carry these systems across the ocean toward the southeastern United States.

When a big one starts to form, meteorologists begin to watch it closely. Some experts even fly into the eye to get a closer look. As the storm approaches land, meteorologists at the Hurricane Center send out advisories every 6 hours.

Researchers can fly into the center, or eye, of a hurricane to learn more about the storm. This photo shows part of the wind-driven wall of clouds surrounding the eye, a center spot of calm air.

NOAA

When they get to land, storms often turn north before cruising east again, back out to sea. But with unpredictable changes in temperature and wind patterns, it doesn’t always work that way.

“Forecasts of the exact track have gotten considerably better over the last 10 years,” Blake says. Still, such predictions are good for only a few hours. And storms are constantly full of surprises.

“Storms can track in all sorts of strange ways,” Klotzbach says. Such quirks keep people glued to their radios and TVs when hurricanes approach land, as they listen for the latest reports on which way a storm is headed.

Future storms

As if that weren’t tricky enough, researchers at Colorado State try to make predictions months ahead of time. Before the start of each hurricane season, they announce how many hurricanes and severe storms they expect will occur in the coming summer and fall.

This sequence of satellite images show Hurricane Georges, which struck in 1998.

NASA

Some years are more active than others. And knowing what to expect is important to lots of people, including emergency managers, insurance companies, and people who live on the coasts. Being prepared can save millions of dollars and lots of lives.

To predict the future, the Colorado State researchers use computer models to look to the past. “Basically, we see what global climate features worked well in forecasting previous years,” Klotzbach says. “We assume the future is going to be like the past.”

For instance, when temperatures at the surface of the Atlantic Ocean are warm in late spring and early summer, the hurricane season tends to be very active. In years that have a weather pattern called El Niño, on the other hand, high winds tend to break storms up, and few hurricanes develop.

Researchers at Colorado State have used such patterns to make predictions for the last 21 years, Klotzbach says. Their predictions are now a lot better than those they made even a few years ago.

Last May, for example, Klotzbach and his team predicted an “above-average” probability of hurricanes hitting the U.S. coast in the coming hurricane season. The researchers said they expected 14 named storms and eight hurricanes.

In fact, August had near-record storm activity, and September was also above average. For now, the researchers expect October to be a little quieter than usual.

Personality

Although there are patterns as to when and where hurricanes occur, every hurricane is different. Each one has its own personality.

In 1900, a deadly hurricane struck Galveston Island, Texas, destroying homes and killing more than 6,000 people. It was the greatest natural disaster in terms of loss of life in United States history.

NOAA Photo Library

To acknowledge that variety, every big storm gets its own name. Storms in the Atlantic are named after people. In the Pacific, storms can be named after flowers or take on nicknames. The World Meteorological Organization decides names in advance, and the alphabetical list rotates every 6 years. Names on the list get replaced only if a storm with a particular name is especially severe—killing lots of people or costing loads of money. That way, the name takes its place in history.

Teddy. Sally. Emily. Dennis. The names may sound friendly. But, watch out. Hurricanes are like bullies. Even with a name like Debby or Charley, big storms can turn on you when you least expect it. Knowing what to look for can help you get out before it’s too late.

Going Deeper:

Word Find: Hurricanes

Additional Information

Questions about the Article

Hurricane Names

All hurricanes are given names. For Atlantic Ocean hurricanes, the World Meteorological Organization has six lists of names, one list per year. The same names are reused every 6 years.

The names may be French, Spanish, or English, one for each letter of the alphabet, except Q, U, and Z. If a hurricane turns out to be especially deadly or costly, its name is retired and a new name is selected to replace it.

Is your name among those in the lists?

The following names have been retired: Agnes, Alicia, Allen, Allison, Andrew, Anita, Audrey, Betsy, Beulah, Bob, Camille, Carla, Carmen, Carol, Celia, Cesar, Cleo, Connie, David, Diana, Diane, Donna, Dora, Edna, Elena, Eloise, Fifi, Flora, Floyd, Fran, Frederic, Gilbert, Gloria, Gracie, Georges, Hazel, Hilda, Hortense, Hugo, Inez, Ione, Iris, Jane, Joan, Keith, Klaus, Luis, Lenny, Marilyn, Michelle, Mitch, Opal, Hattie, Roxanne.

Source: Federal Emergency Management Agency

A new study offers a helpful suggestion for these kids: Go for a nature walk.

A walk in the woods can help kids cope with attention disorders.

U.S. Fish and Wildlife Service

Researchers from the University of Illinois at Urbana-Champaign gave a questionnaire to parents of children with ADHD. The questions focused on how the kids respond to various extracurricular activities in different settings. Choices for settings included leafy backyards, indoor playrooms, and city playgrounds. A group of 452 people completed the survey over the Internet.

The results of the questionnaire showed that the kids were more focused and paid better attention when they were in “green” outdoor environments than when they were in others. It didn’t matter how many other kids they played with or even if they played alone.

To really get at the effects of the environment, the researchers analyzed only activities that could be done anywhere. They didn’t include watching TV, for example, because that only happens indoors. And hiking is limited to the outdoors, so that didn’t count either. This analysis produced similar results.

The findings reinforce the idea that the environment, on its own, influences attention skills, the researchers say, regardless of the activity.

In yet another study, a group of kids with ADHD took a 20-minute guided walk on a nature trail. Another group took a 20-minuted guided walk on a city path. At the end of the walk, kids in the nature group scored better on attention tests than kids in the city group.

The studies didn’t look at kids without ADHD. Still, the advice might hold for everyone. If you find yourself dozing off or getting distracted while doing your homework, get out and walk in the woods for a few minutes. Make sure you come back, though. You still have to do the work sometime!—E. Sohn

Going Deeper:

Harder, Ben. 2004. Nature reduces kids’ signs of attention disorder. Science News 166(Sept. 18):190. Available at http://www.sciencenews.org/articles/20040918/note16.asp .

Sohn, Emily. 2004. Roller coaster thrills. Science News for Kids (June 16). Available at http://www.sciencenewsforkids.org/articles/20040616/Feature1.asp .

______. 2004. What video games can teach us. Science News for Kids (Jan. 21). Available at http://www.sciencenewsforkids.org/articles/20040121/Feature1.asp .

______. 2003. Brain signals attention disorder. Science News for Kids (Dec. 3). Available at http://www.sciencenewsforkids.org/articles/20031203/Note2.asp .

______. 2003. A classroom of the mind. Science News for Kids (Oct. 22). Available at http://www.sciencenewsforkids.org/articles/20031022/Feature1.asp .

Information for kids about attention disorders can be found at the Attention Deficit Disorder Association’s “Kid’s Area” at www.add.org/content/kids1.htm (Attention Deficit Disorder Association).

Astronomers have found evidence of more than 125 planets around other stars in the universe, but no one has ever seen one directly. These planets are so faint they get lost in the glare of their parent star. Instead, astronomers have relied on indirect clues about how the planets affect nearby objects to pinpoint them.

This photo, taken in near-infrared light, shows a red spot that may be a planet orbiting a type of star called a brown dwarf. The star is 230 light-years from Earth.

European Southern Observatory

Now, scientists may have finally snapped a photo of an extrasolar planet. It orbits a star 230 light-years from Earth. The star is a brown dwarf, a collapsed ball of gas that doesn’t give off light the way most stars do.

The planet is about 55 times as far from the star as Earth is from the sun. It also appears to be huge—about five times as massive as Jupiter.

To get the picture, astronomers from the European Southern Observatory used something called an adaptive-optics system on the Observatory’s Very Large Telescope in Paranal, Chile. The system has a special mirror that keeps changing shape. The technology removes blurring caused by turbulence in our planet’s atmosphere.

Besides getting the planet’s image, the researchers were also able to determine that the object contains water vapor. That would make it too cool to be another star.

Next, the researchers plan to follow the movement of the object, to make sure it behaves like a true planet and orbits the star.—E. Sohn

Going Deeper:

Cowen, Ron. 2004. Sky lights: Picture might show an extrasolar planet. Science News 166(Sept. 18):179. Available at http://www.sciencenews.org/articles/20040918/fob1.asp .

Sohn, Emily. 2004. Planet hunters nab three more. Science News for Kids (Sept. 8). Available at http://www.sciencenewsforkids.org/articles/20040908/Note2.asp .

______. 2003. A planet from the early universe. Science News for Kids (July 16). Available at http://www.sciencenewsforkids.org/articles/20030716/Note2.asp .

______. 2003. A planet’s slim-fast plan. Science News for Kids (March 19). Available at http://www.sciencenewsforkids.org/articles/20030319/Note2.asp .

You can learn more about the photo of what may be a planet orbiting a star at www.eso.org/outreach/press-rel/pr-2004/pr-23-04.html (European Southern Observatory).

“That’s one of the great questions of humanity,” says David Wettergreen. He’s a robotics scientist at Carnegie Mellon University in Pittsburgh.

“Are we alone or not?” Wettergreen asks. “You can spend your whole life pondering this question.”

Instead of just thinking about the question, Wettergreen wants to answer it. And he’s getting funds from the National Aeronautics and Space Administration (NASA) to help find an answer.

The space agency has a project called the Astrobiology Science and Technology Program for Exploring Planets (ASTEP). Astrobiology is the study of life in the universe. One way that NASA researchers have looked for signs of life in outer space is by sending signals into the void and listening for a response. So far, these messages have turned up nothing but silence.

Wettergreen has a different strategy, and it begins right here on Earth. Earlier this month, he and his team traveled to one of the driest, most desolate places on the planet—the Atacama Desert in northern Chile. Conditions there are similar to conditions on Mars. And, because the landscape is so dry, scientists argue about whether any sort of life could possibly survive in the desert on its own.

A view across the desolate Atacama Desert in Northern Chile.

Carnegie Mellon University

In the Atacama, Wettergreen and a team of researchers use an equipment-loaded robot to search for pockets of life. The scientists want to learn if, how, and why anything can survive in such harsh conditions.

“Our ultimate goal is to discover something unique about the Atacama,” says Wettergreen. In a broader sense, he says, the techniques used on the mission could eventually help astrobiologists explore other parts of the solar system.

“We’re trying to learn about the desert,” Wettergreen says, “and about how you go looking for life.”

The 3-year project is now in its second year. You can follow the current expedition and view images from the robot rover on the Web at http://www.frc.ri.cmu.edu/atacama/ (Carnegie Mellon University).

Roving robot

The team’s most valuable member is not a person. It’s a robot named Zoë. Zoë happens to be the Greek word for “life.”

Zoë is about the size of an office desk. It’s 1 meter high and 2 meters wide, and it weighs about 180 kilograms. Its top speed is 1.2 meters per second. It carries an array of solar cells on its back to collect energy from the sun.

The robot rover Zoë is about 1 meter tall and 2 meters wide. It weighs 180 kilograms.

Carnegie Mellon University

The robot is similar to the rovers Spirit and Opportunity, which are currently on Mars. The scientists give Zoë a general program telling it what to do. The vehicle then explores the landscape. As it cruises around, Zoë sends data back to the researchers. Nobody drives it, and there’s no remote control.

Using a robot allows the researchers to take frequent measurements over a large area, creating a sort of catalog of what’s out there.

Last year, the team spent about a month in the Atacama just developing and testing instruments for Zoë. The robot carries three sophisticated cameras that record everything in very clear, color images. To mimic the 3-dimensional view that a person would have while walking around, the cameras sit close to each other just above eye-level.

To detect microscopic life on the ground, Zoë carries a fluorescence imager.

Fluorescence occurs when a substance absorbs certain kinds of electromagnetic radiation, such as ultraviolet light or x-rays, and gives off visible light of a particular color in return. As soon as the ultraviolet light or other source is turned off, the substance stops giving off visible light.

Because different materials absorb and give off different colors of light, Zoë can detect and distinguish between various kinds of minerals and molecules.

A rock (left) contains certain minerals and other substances that fluoresce, or give off light, at certain wavelengths (right), allowing them to be identified.

Carnegie Mellon University

Zoë also carries a spectrometer, which analyzes how objects in the soil reflect light. The spectrometer detects which particular colors, of wavelengths, of visible and infrared light are reflected by soil particles. Like fingerprints, particular patterns of wavelengths correspond to different minerals.

The robot also has a plow that can turn over rocks and dig into the soil, allowing the fluorescence imager and spectrometer to examine what’s under the surface.

Field life

Even though the robot does much of the work during the research mission, life in the field isn’t easy for the researchers. “We work from dawn until dusk, 7 days a week,” Wettergreen says. The scientists and technicians have to make sure that Zoë is working correctly, and they must sift through loads of data transmitted by the robot.

Camping out in the desert with Zoë.

Carnegie Mellon

The environment can be hard to adjust to. Less than a centimeter of rain falls on the Atacama every year. A bone dry, rocky landscape stretches as far as the eye can see. There are no trees, no lakes, no little animals scurrying around. The only contrast is the brilliantly blue, cloudless sky above.

Atacama’s mixture of dirt and rock. An ordinary pen gives you a sense of how large the pebbles are.

Carnegie Mellon University

“In the Atacama, you see rock and soil in all directions and really nothing else,” Wettergreen says. “When you look up, it’s blue. When you look down, it’s brown. With the midday sun overhead beating down on you, it does seem desolate.”

Still, Wettergreen and his colleagues are convinced that there is more to the Atacama than meets the eye, and they’re determined to prove it.

“We are finding that the desert is not uniform,” he says. “There are microhabitats, small oases. Sometimes a single rock provides shelter or a trap for moisture.” Water is often the first sign that there might be life around.

If Zoë finds good ways to look for these hidden specks of life, scientists might eventually make similar discoveries on Mars and beyond. That would answer one of life’s biggest questions, and stargazing would gain a whole new meaning.

Going Deeper:

Word Find: Alien Life

Additional Information

Questions about the Article

Atacama Facts

The Atacama Desert in northern Chile.

Carnegie Mellon University

The Atacama Desert in northern Chile is less than 100 miles wide and about 600 miles long. It’s located between the Pacific Ocean and the Andes Mountains.

The Atacama is made up mainly of salt basins, sand, and lava flows.

Unlike other deserts, the Atacama is quite cool, with average daily temperatures ranging from 0 to 25 degrees Celsius.

The area gets an average of less than 0.004 inch (or 0.01 centimeter) of rain per year.

A burrowing owl spreads dung around its nest, attracting beetles.

R. Wolfe

Burrowing owls collect the dung of cows and other mammals, and they bring the waste patties to their nests in the ground. Birdwatchers have noticed this for a long time. They’ve also noticed that if the dung disappears from the burrow early in the breeding season, the birds will replace it. Why they do this has been a mystery.

To solve the puzzle, scientists from the University of Florida in Gainesville tested several theories. One idea was that the smell of the dung overpowered the smell of eggs. That might keep predators away. In a test with fake burrows, however, predators were equally attracted to lairs with and without dung.

Next, the researchers set up traps with dry dung as bait. Other traps had moist dung, as if there had been a heavy rain. In both cases, the dung attracted dung beetles, though the wet dung attracted more. Owls like to eat beetles. So, maybe the dung was working as bait, like worms on a fishing rod.

For the final test, the researchers observed 10 burrows over 4 days. When they took the dung away from a burrow’s entrance, the owls had few beetles to eat. When the researchers added dung, the birds ate 10 times as many beetles.

The scientists propose that the owls use dung like a tool to attract beetles to eat. It’s not something you would want to try at home. But for the birds, it seems to work.—E. Sohn

Going Deeper:

Milius, Susan. 2004. Owls use tools: Dung is lure for beetles. Science News 166(Sept. 11):173. Available at http://www.sciencenews.org/articles/20040911/note12.asp .

Sohn, Emily. 2003. Better tools for techno-crows. Science News for Kids (March 26). Available at http://www.sciencenewsforkids.org/articles/20030326/Note3.asp .

You can learn more about burrowing owls at www.owlpages.com/species/athene/cunicularia/Default.htm (Owl Pages).

A ringed turtle-dove uses superfast muscles to coo.

Judith S. Anderson

Scientists have found high-speed muscles in a variety of animals. These tissues can contract and relax amazingly quickly. Among the very fastest are muscles in toadfish. These creatures make muscles in their swim bladders move very quickly to produce sounds. Rattlesnakes have superfast muscles in their tails, so they can shake, shake, shake.

When ringed turtle-doves (Streptopelia risoria) coo, they make a lot of very short, fast sounds in row. Researchers from the Netherlands and the United States suspected that the birds might have speedy muscles, too.

To find out, the scientists implanted tiny electrical devices in the structures that the birds use to make sounds. When the birds cooed, the electrodes indicated which muscles contracted and relaxed over and over.

These particular muscles control membranes in the throat. The membranes vibrate when air passes through from the lungs.

Ringed turtle-dove on the ground.

© Bill Horn,

Next, the researchers removed the muscles that control the membranes and tested them in the lab. They found that these muscles, outside of the bird, contract and partly relax in just 9 to 10 milliseconds. A typical animal muscle takes at least 100 milliseconds to do the same thing.

All sorts of other birds might have superfast muscles, the researchers propose.

Songbirds, in particular, tend to have complex songs. Birdsong researchers have already learned a lot about how bird brains work when birds sing. When it comes to chirping the melodies of springtime, though, muscle speed could be just as important.—E. Sohn

Going Deeper:

Milius, Susan. 2004. Super bird: Cooing doves flex extra-fast muscles. Science News 166(Sept. 11):166. Available at http://www.sciencenews.org/articles/20040911/fob7.asp .

Note: The ringed turtle-dove (Streptopelia risoria) is also known as the ringdove, ringneck dove, ring-necked dove, Barbary dove, laughing dove, and turtle dove.

You can learn more about ringed turtle-doves at birds.cornell.edu/pfw/AboutBirdsandFeeding/EucdovRitdovID.htm (Project FeederWatch, Cornell Lab of Ornithology) and natureali.org/ringeddove.htm (Nature Alley).

Penguins have flexible, powerful flippers that allow them to maneuver quickly and smoothly in water.

Dolphins and seals can perform similar aquabatics.

These marine animals are more than just fun to watch. They’re also inspiring engineers to look for better ways of propelling boats. You never see a submarine do what a penguin can do, but wouldn’t it be cool if it could?

Propellers let ships travel in a relatively straight line over great distances. Today’s engineers are trying to design vessels that can do a lot more than that. They want boats able to withstand stormy conditions that would shatter an existing craft. They want boats that can maneuver quickly in tight spaces. They want boats that can sense currents or waves and respond in a split second to hold their position. In effect, they want to reinvent the penguin—or perhaps the whale or fish.

A penguin’s flippers are a good starting point.

All dressed up

Propeller blades just spin. Penguin flippers do much more.

A penguin’s flipper is like a hard, stiff paddle covered with tiny feathers. It’s shaped a bit like an airplane wing. A flipper can flap up and down, move forward and backward, and twist around at the joint where it’s attached to the penguin’s body.

At the Massachusetts Institute of Technology, researchers are working on a new propulsion system for ships that mimics a penguin’s flippers. Their artificial wooden flippers move a boat forward or backward by generating high-energy rings of spinning water. Other flipper movements steer the craft right, left, up, or down.

The MIT team is now testing how various flipper movements affect a boat’s motion, doing experiments in giant basins of water.

The scientists envision using a pair of flippers in place of a propeller to move a boat along. More futuristic vessels could have as many as 50 flapping flippers, each one moving independently.

But it’ll take many more years of research before the Navy or anyone else can launch high-tech ships driven by flippers.

A new kind of fin

Flexibility also helps move things along in water.

Marine animals such as dolphins and seals aren’t made of stiff materials. They’re squishy, like human skin and muscle.

Flexible materials can store energy in ways that stiff ones can’t. When a dolphin flexes its tail as far as it’ll bend, it stores energy in its body—just like a stretched rubber band. When the tail slams down and straightens, this stored energy is released, and the dolphin shoots forward.

Engineers at Nekton Research, a company in Durham, N.C., have designed flexible fins for an underwater vehicle to take advantage of such cycles of storing and releasing energy.

The craft, called PilotFish, is shaped like a giant egg with four fins coming out of its waist. It’s more than 3 feet long and weighs 350 pounds.

PilotFish is shaped like an egg with four fins coming out of its waist.

Nekton Research

PilotFish can’t travel long distances quickly. Instead, maneuverability is its specialty. And it can get going in a fraction of a second. Moreover, unlike any other watercraft, it can stop almost instantaneously just by slamming its fins forward.

“The thing looks like it hit a wall. It stops dead,” says Chuck Pell, who helped design the fins. “The only other things that can do that are alive.”

PilotFish is designed to operate in water too turbulent for other craft. For example, it could be used to inspect the underwater portions of structures such as bridges and docks.

Each of PilotFish’s flexible fins is connected to a motor inside the craft.

Nekton Research

A river’s waves or current can easily overcome or carry away a propeller-driven craft before it can perform an inspection. In contrast, PilotFish reacts to its environment quickly enough to stay in place. If the craft encounters an unexpected object, it can immediately stop to avoid bumping into it. If a wave rolls it over, PilotFish can right itself before the next wave comes.

To accomplish all this, PilotFish’s fins generate huge forces. “You have to careful around it. You could break an arm,” Pell says. He notes that he once ended up with a sprained wrist when a moving fin accidentally struck his hand.

Whale watch

For their size, humpback whales are surprisingly agile. This 50-foot, 30-ton animal can swim in a tight corkscrew pattern, sometimes less than 10 feet across.

A humpback whale shows off a side flipper with its distinctive scalloped edge.

W. Rossiter

The whales do this not for fun but to capture a meal. They blow bubbles as they swim in this spiral pattern, creating a rising barrier around a cylinder of water. Tiny shrimp and small fish get trapped in the cylinder, and the whale simply swims up through the concentrated feast for its meal.

Scientists have long wondered how humpbacks manage this feat. They’ve been particularly curious about bumps along the leading edge of a humpback’s long, narrow flippers.

To find out, researchers built two artificial whale flippers. One flipper had a scalloped edge, and the other was smooth. They then tested the two flippers in a wind tunnel. Although air is much less dense than water, it’s still a fluid, and the researchers could adjust the air’s speed so that it behaved like water rushing over a humpback’s flipper.

Researchers built models of a humpback whale’s flipper (left) and another whale’s flipper (right) to compare their performances.

L. Howle

The scientists found that the bumps reduce drag and increase a flipper’s lift so it behaves more like an airplane wing. This extra lift and reduced drag lets a humpback whale make sharper turns than other whales can make.

Someday, engineers designing flippers or fins to drive boats and submarines might add bumps or scallops, too.

Kayak flippers

Artificial fins inspired by one marine animal, the penguin, are already available—though not where scientists might have predicted. They’re in a foot-powered propulsion system for kayaks designed by engineers at Hobie Cat in Oceanside, Calif.

The two underwater fins of a Hobie Cat kayak are powered by a person pedaling while sitting on the craft. They are more efficient than hand-held oars.

G. Ketterman

Instead of paddling, you sit in the kayak and pedal with your feet. Your pedaling powers two flexible fins.

At the start of each stroke, the fins twist and flex in such a way that they assume the shape of a propeller blade. A penguin’s flipper flexes in the same way when the swimming bird wants to move itself forward.

The fins move larger volumes of water than a traditional oar can yet require less energy to do so. This lets kayakers go farther and faster, without getting as tired as when paddling with oars.

Hobie Cat’s pedaled kayaks are leading the way in applications of nature-inspired flipper design. Other applications are bound to follow.

Maybe someday you’ll be able to go to an aquarium show featuring underwater vehicles, gliding gracefully, racing around rocks, and leaping out of the water to wow a crowd—doing what comes naturally to penguins and dolphins.

Going Deeper:

Word Find: Engineering Fins

Additional Information

Questions about the Article

Humpback Whale Facts

Adult males measure 40 to 48 feet; adult females measure 45 to 50 feet.

Adult humpbacks weigh 25 to 40 tons.

The whales feed on krill and various kinds of small fish.

They are found in all the world’s oceans. Most populations of humpback whales follow a regular migration route, summering in temperate and polar waters for feeding and wintering in tropical waters for mating and calving.

Its flippers are very long, between one-quarter and one-third the length of its body.

Source: American Cetacean Society (www.acsonline.org/)