Greene, a tall, white-bearded man with observant, kindly eyes, somehow projects an air of adventure even when he's not carrying his favorite snake-handling stick. Besides being a professor of integrative biology at UC Berkeley, he's also the curator of herpetology -- the study of reptiles and amphibians -- at its Museum of Vertebrate Zoology. He spends weeks and even months of every year camping in the wilderness, studying snakes.
One of the world's leading experts on snakes, Greene has recently published an exhaustive and amazing work on the subject, titled Snakes: The Evolution of Mystery in Nature. The volume is one of the most complete available on snake biology, and the text is complemented by a gallery of gorgeous photographs by Michael and Patricia Fogden. Its most engaging feature, though, is a collection of personal essays in which Greene explores his own obsession with snakes.
The idea for the book was born when Greene met Norman Maclean, author of A River Runs Through It, at a dinner party. A star-struck Greene began explaining his plans for a book about his experiences as a medic in Vietnam. Maclean, then well into his 80s, brusquely interrupted him. "Just tell me why you want to work with those damned old rattlesnakes!" he ordered.
Greene has been trying to answer that question ever since. A scientist whose doctoral dissertation focused on behavioral evolution, he thinks his interest stems in part from the ambivalent snake fascination that humans as a species have displayed since prehistoric times. Several millennia ago, he theorizes, our ancient ancestors both feared and sought out snakes -- because while a few species were deadly, all were good eating. "Most major groups of primates kill and eat snakes," explains Greene. "They're just a great little grocery item. They're easy to kill, come in a nice neat package, and contain a lot of nutrition for their size.
"On the other hand, they can kill you, and some of them even eat you."
Perhaps because they are inscrutable and silent, snakes have long represented different things to different people. Most famously, there's the biblical myth of the serpent in the Garden of Eden. There's also ophiolatry, the worship of snakes, a feature of many cultures from ancient Greece to aboriginal Australia.
But mostly, people view snakes with fear and revulsion, which helps explain why, of the 2,700 species of snakes in the world, 200 are now endangered. Here in the west, timber rattlesnakes face extinction over large parts of their range. Massasauga rattlesnakes in Arizona and New Mexico are threatened by the conversion of natural grassland to farmland. And in Oklahoma and Texas, towns hold "rattlesnake roundups" -- public slaughters of western diamondbacks.
Saving animals from extinction is hard enough, but it's a lot harder when people don't like the animals in question. Greene quotes Senegalese conservationist Baba Dioum: "In the end, we will conserve only what we love, we will love only what we understand, we will understand only what we are taught."
But loving snakes, or even understanding them, isn't easy. "It's hard for us to empathize with snakes," admits Greene. "There are almost no external references for us. They don't have movable eyelids, their lips aren't flexible -- there's nothing to convey their emotional state." To his mind, though, the very snakiness of snakes is a big part of what makes them so worth studying.
Much of the cutting-edge work in zoology today is in re-examining human perceptions of animal intelligence. The pioneer in this area is Donald Griffin, the scientist who became world famous in the 1970s by discovering bats' ability to locate objects in the dark through the reflection of sound. Griffin went on to publish The Question of Animal Awareness: Evolutionary Continuity of Mental Experience, the first major work to suggest that animals might have more intelligence, and more complex inner lives, than humans had previously thought.
The academic community was divided -- and still is -- between scientists who thought Griffin's research placed him on a level with Charles Darwin, and those who thought his work was sentimental and, worse, unscientific. Greene is in the former camp, and believes Griffin's ideas about re-evaluating animal intelligence may be particularly applicable to snakes.
Because snakes -- limbless, expressionless, and nearly mute -- give almost no clues about what they're thinking, they may also force animal behaviorists to examine their own methodology. "Snakes are especially challenging," says Greene. "If we can think through ways to ask questions about snakes, it should be easier to ask them about, say, cats. So in that way, snakes may play a special role in helping our understanding of animal intelligence."
Since Griffin's groundbreaking work, scientists have begun looking to animals to understand humans and human behavior. Though much of this research focuses on primates like gorillas and chimpanzees, other researchers have argued that by studying other species, among them lions and various types of birds, we can learn about the evolution of social behavior and communication among humans.
One of Greene's experiments in snake intelligence tested whether baby hognose snakes' responses to a threat might change if the snakes thought the situation had changed. Animal intelligence researchers think an animal demonstrates consciousness and awareness if it finds solutions to changing and unforeseen problems.
Surprisingly, the little snakes feigned death only when they thought a "predator" (a stuffed owl) was watching them. "It's incredible," says Greene. "Their tongue hangs out on the dirt, they even shit on themselves."
But when the owl was turned to face away from the snakes, they immediately flipped over and began crawling away, only to repeat the whole performance when the researchers turned the owl around again. Obviously, the snakes were adapting their behavior to the changing situation.
To get to UC Berkeley's snake rooms, you pass through two heavy sets of locked doors, as required by state regulations for the control of hazardous materials. Most of the glass tanks inside bear cards stamped with the word "venomous" in block capitals. There is a buzzing noise, as though a ballast in one of the overhead fluorescent lights is malfunctioning.
"Hear them rattling?" asks Greene. "That's these guys down here." He lifts the lid off a tank and the sound becomes much louder. This is his favorite snake -- a 3-foot-long female western rattlesnake he collected years ago in Lassen Park. Coiled into heavy loops, she rattles threateningly, but Greene says she's actually mild-mannered. Using his hooked aluminum snake-handling stick, he lifts her gently out onto the floor.
The snake hesitates a moment. Greene offers her a clear plexiglass tube, a tool herpetologists use to study venomous snakes without danger of being bitten. After a second or two, the rattlesnake glides obligingly into it, and he lifts her again, her head and front third of her body now encased in the tube.
The snake watches the humans, her black eyes glittering. What is she feeling? What is she thinking?
Greene observes her fondly. "As for the snakes themselves, we still can't say what it's like to actually be a blacktailed rattle-snake ...," he writes at the conclusion of his book. "I must go farther and closer.