Animal Talk: Breaking the Codes of Animal Language - Couverture rigide

Friend, Tim

Couverture rigide

ISBN 10 : 0091875242 ISBN 13 : 9780091875244

Editeur : Ebury Press, 2099

Synopsis

A survey of where modern science stands on this fascinating subject, which presents some extraordinary new and unpublished evidence in a number of areas, and provides many remarkable accounts of animal behaviour which defies the conventional explanations.

A propos du livre

Extrait

Chapter One: A Walk in the Park: Toward a Universal Language

Just before midnight, I crawl off my hammock and slip quietly from under the blessed drapes of mosquito netting. The kerosene lanterns have been dimmed to barely a flicker across the long raised wooden platform that serves as our base camp in the tropical rain forest of northwestern Peru. The platform is in the center of a clearing next to the bank of a small tributary that feeds into the Napo River half a mile away. I arrived with four other journalists and a guide late in the afternoon after hiking through the muddy and tangled jungle since early morning. We have joined two scientists, a few camp cooks, and the drunken pilot of a Cessna seaplane, who arrived just before dinner. The pilot is supposed to give us a flyover of the region first thing after breakfast. As much Johnny Walker Red scotch as he was putting away tonight, he'll still be drunk when we take off on the river early in the morning. The bush pilot's creed is, If you can't fly drunk, you can't fly.

This is my first trip to the Amazon rain forest. The closest I have come to a jungle until now is the tangled thicket of the Ozarks, where I grew up. Surprisingly, there are a lot of similarities, especially in the number of things that bite, sting, scratch, and burn. At the moment, the others in the expedition party are snoring. But that isn't why I'm awake. There's a raucous party going on -- with lots of wild action by the strange and wondrous creatures all around our campsite. The night is teeming with sounds that seem louder and more intriguing than anything I have ever heard.

A minute ago, high in the canopy just beyond the camp's perimeter, something big crashed through the leaves. The only creature large enough around here to make such noise is a sloth. True to its name, it does not seem to be in much of a hurry. Bats have been fluttering since dusk through the rafters of the thatched roof above the platform. Earlier this evening, one swooped down and snatched a tarantula that was crawling up a colleague's mosquito netting. We could hear a soft crunch as the bat caught the spider with its teeth and darted off with its dinner into the night.

Beyond the camp, in vibrant surround sound, tree frogs and insects are laying down a soulful, energetic chorus like a choir at an old-fashioned Southern tent revival. Unfamiliar birds and nocturnal monkeys overlay the chorus with melodies and their own unique lyrics. This is one party I am not going to miss despite the rather condescending warning of the scientists not to leave camp alone at night. We could get lost or worse, they cautioned. I spend quite a bit of time in the field, but no matter where I travel, scientists tend to treat journalists like bad children who need constant supervision. Their admonishment only heightens my resolve to sneak out of camp.

The main attraction of this remote spot in the jungle is a canopy walkway constructed with ladders and suspension bridges that leads 115 feet straight up to the tops of the trees. Ordinarily, getting to the upper canopy entails climbing with harnesses and ropes. This is no simple task and usually involves close encounters of the unpleasant kind with nasty things that sting, burn, and bite. The canopy walkway, which bears a strong resemblance to the Swiss family Robinson's tree house, is a vast improvement on grappling and slapping one's way up. As far as I know, only a few of these walkways exist in the world. Tonight, this one is going to be my stairway to heaven.

I am on a mission and have a woefully short time to fulfill it: to learn how animals communicate with each other and what they spend so much time chattering to each other about. At this point, my quest seems absolutely overwhelming. Real experts devote entire careers to studying a single species of animal and are still left with many more questions than answers at the end of the day. My head is full of questions, too, which I plan to explore and explain in this book: If animal behavior is mostly instinctual, as scientists generally thought for more than a hundred years, why do animals need to communicate? If animals are thinking creatures and capable of emotions, as a growing number of scientists now believe, do their signals convey information (similar to our words)? Or are animals merely snarling or cooing to manipulate each other's behavior to get something they want (as we also often do)? How did the colorful, noisy, and smelly signals of the animal kingdom arise in the first place? Is any animal system of communication similar to human language? Do animals ever lie or attempt to deceive each other when communicating? Do the chirps, barks, and roars of different species have anything in common or follow predictable rules or patterns? Can a bird understand a monkey? Do species learn to communicate or is it all programmed by genes? To what extent is human communication, both verbal and nonverbal, programmed into our genes?

Scientists have been asking questions like these and working hard at finding the answers for more than a century, but there have been an enormous number of recent discoveries about animal communication. Studies on communication among tree frogs alone could fill a book. The eminent sociobiologist E. O. Wilson and the entomologist Bert Hölldobler produced a 732-page tome devoted to ants. I have three books in my home library on cichlid fishes, seven devoted to primates, five on dogs, more than a dozen on various species of birds. Most books focus on a single behavior, such as courtship rituals among birds, or the social behavior of primates, or the chemical signals of insects.

Yet surprisingly few books written for the general public have focused on the great range of animal communication. Usually, these books devote only a chapter or two to songs, dances, and scents. So my challenge here is to draw from the wealth of research conducted by hundreds of scientists and present the bigger picture of animal talk in the wild. The Amazon rain forest seemed like the best place to get a full immersion in nature and to begin eavesdropping on some animal conversations.

The few remaining unspoiled rain forests of the world are nature's Manhattan, London, and Tokyo -- bustling organic metropolises with their own laws that govern every creature equally from conception through life and into death. The laws of nature demand procreation and a fight for survival, but the means developed to achieve those ends are tremendously varied. Mother Nature has fostered all manner of societies, cultures, learning, gaming, altruism, deception, cooperation, competition, industries, arms races, and intelligence. Look closely at any habitat and you can find daily dramas involving struggles between predators and prey, elaborate courtships, covert copulations, sibling rivalries, struggles for dominance, defense of territories, and many, many opportunities to arrive at a premature death. The same dramas are played out all over the world in every environment, from the deep ocean vents where microscopic life may have begun to the lawns and shrubs only a few steps away in the backyard.

Communication between all of the earth's creatures makes these dramas possible. Indeed, communication is the glue of animal societies. Without a means of communicating, no life, including the simplest single-celled organisms, could exist. Communication, like the tango, takes two. And it requires a signal, which can be anything from the release of chemicals between colonizing bacteria, to the come-hither flashes between male and female fireflies in the backyard, to the "let's go" rumble of African elephants, to the "signature" whistles of dolphins, to a dog barking simply to be let outside.

Over the course of our journey we will explore the origins of communication and how all of the marvelous signals employed by animals have developed. We will also look at why scientists think the way they do about animals. A pretty big divide separates scientists and laypeople, especially in their perspectives on animal behaviors. Yet, as ordinary people and pet owners become more informed and as scientists come to better appreciate the genuine intelligence of their animal subjects, both groups are moving toward a middle ground.

Before we head off into the jungle and climb the canopy walkway, we ought to know what scientists mean when they talk about animal communication. The basic textbook definition of animal communication taught to most undergraduate students states that it is "the provision of information by a sender to a receiver, and the subsequent use of that information by the receiver in deciding how to respond. The vehicle that provides the information is called the signal." One example of animal communication is the exchange between songbirds in a tree in the backyard. The male songbird is usually the sender. He sings his repertoire of songs, which is the signal, to a female songbird that has lighted on a nearby branch to listen. She is the receiver. The information would be something contained in the male's songs that helps the female decide whether the singer is a suitable mate. An exception to this male-dominated art and science is the northern cardinal -- each sex sings to the other, and they even seem to duet. My mom's fat little Chihuahua, Taco, is another example. Taco has a habit of running to my mom and barking in a particular manner whenever my dad does not hang up his jacket when he comes home from work. Taco is the sender. Mom is the receiver, and the information is that dad left his jacket on the bed. (How my mom knows Taco's bark carries this specific meaning, however, is a mystery.)

E. O. Wilson takes the definition a bit further in Sociobiology: The New Synthesis. Wilson defines communication this way: "Biological communication is the action on the part of one organism (or cell) that alters the probability pattern of behavior in another organism (or cell) in a fashion adaptive to either one or both of the participants. By adaptive I mean that the signaling, or the response, or both, have been genetically programmed to some extent by natural selection. Communication is neither the signal by itself nor the response; it is instead the relationship between the two."

The exchange of chemical signals between bacteria is the oldest form of communication on the planet and provides a good example of Wilson's definition. For pathogenic bacteria to become harmful to us humans, they first need to reach a critical mass, which they do by communicating with each other essentially to take a head count. A single E. coli bacterium -- the type that naturally lives in our gut but sometimes contaminates foods -- will release a chemical signal that sends the message "I am here." If pathogenic bacteria are present, the message will cause them to release a similar signal that says "I'm here, too." If the bacteria sense that their numbers are strong enough to ward off an attack by the host's immune system, they will all respond by releasing their toxins into the host's cells. The signals are genetically programmed and create a dynamic relationship between the senders and receivers, a type of bacterial communication known as quorum sensing.

All types of chemical signals, including those used by animals to attract mates, are adaptive, by Wilson's definition. Chemical signals originated with the first group of bacteria that appeared on the young earth, about 3.8 billion years ago. Thanks to their highly effective signaling, bacteria often function as a type of superorganism and are one of the most successful forms of life on earth. They are also the only life-form that appears capable of living elsewhere in our solar system.

The signaling that allowed colonies of bacteria to thrive in all types of environments, from ocean vents to glacier ice, eventually gave rise to the cell-to-cell communication that made possible the evolution of multicelled organisms. This "adaptive" communication has facilitated the incredible success of the earth's insects, including the 8,800 species of ants, which Wilson and Hölldobler say constitute an amazing 15 percent of the earth's biomass. In fact, Wilson developed his definition of communication from the study of ants, which have evolved a complex social system by using specific chemical signals with unambiguous meanings. Any given chemical signal produced by a sender will elicit a specific, invariable response from a receiver. For example, if an invader enters a colony of fire ants, sentries will release a chemical alarm that summons other members of the colony to attack the invader. The members of an ant colony also carry a chemical badge that says to the others "I belong here." Spread a little of that chemical badge on an invader and the sentries will allow it to enter the colony as one of their own. The chemical signals used and understood by ants are obviously programmed into their genes.

The communication systems of all living creatures are programmed to some extent by genes. While genes rule supreme over insect communication, many mammals and birds have some flexibility for learning certain types of signals. Songbirds inherit a fixed genetic template of the songs they will sing as adults, but they must hear the songs of adults during a critical period of development

to sing their songs correctly when they grow up. Some birds, such as cowbirds, can learn the songs of a different species. Cowbirds, known for laying their eggs in the nests of other birds, including golden warblers, are born with a genetic template for their own species' songs, but when raised in the nest of the golden warbler, they learn to sing the songs of their foster parent.

The development period of song learning among birds is similar to the babbling phase of human babies and other young primates, such as the vervet monkeys that live on the African savanna. Vervets are born with a genetic template for specific types of calls, but they must learn to use them in the proper contexts by observing adults. The foundation for human language -- grammar and syntax -- is genetically programmed in humans, but the ability to speak human language must be learned from exposure to adult speech. Many species of animals depend on experience and learning to communicate. The difficult part is figuring out which species need to go to "school" to communicate effectively and which are fully programmed by their genes. Humans are regarded by humans, of course, as the savants of communication. It may seem logical to conclude that the complexity of communication systems follows a hierarchy leading from humans to apes to mammals and birds and on down to insects. But it's not so simple. The most complex system of communication next to that of humans is found in the dance steps of the honeybee.

How can that be? Nature isn't concerned with how an organism communicates as long as it finds a way to do it successfully. The forces that help an organism achieve a successful system for communicating -- whether simple or complex -- are known as natural selection and sexual selection.

Natural selection basically means that nature favors any trait that improves an animal's chances of survival. If screaming a warning or releasing a certain chemical when a predator is sighted helps keep the family or kids from becoming dinner, then nature will favor those signals, which will become established in a species.

Sexual selection is an equally powerful force that shapes an animal's come-hither signals, such as lilting songs and flashy ornaments or displays. Sexual selection favors any signal that helps an animal win at the mating game. Whichever of the sexes is in the driver's seat when it comes to choosing a partner --...

Présentation de l'éditeur

If animal behavior is mostly instinctual, why do animals need to communicate? Is it possible that there is a universal language spoken and understood by all animals on earth, including humans? Do barks, growls, rumbles, chirps, yips, and meows have communicative meanings?
"No matter what species," writes acclaimed science journalist Tim Friend, "we're all concerned with the same topics of conversation -- sex, real estate, who's boss, and what's for dinner." In Animal Talk, Friend draws upon years of field research, interviews with preeminent scientists, and lively personal anecdotes to find out how our animal neighbors communicate and what their languages mean. From bird calls to whale songs, laughing hyenas to rattling snakes, an elephant cry in the jungle to the bark of a Chihuahua in his own backyard, Friend tells the grand story of animal communication through the sounds, stripes, scents, and signals of the animals themselves.

Détails de l'édition

• Éditeur: Ebury Press
• Date d'édition: 2099
• ISBN 10: 0091875242
• ISBN 13: 9780091875244
• Reliure: Relié
• Langue: anglais
• Nombre de pages: 256
• Coordonnées du fabricant: non disponible