Snakes have an image problem. That makes saving them a challenge.
By Phyllis Mcintosh
On any busy day at the Smithsonian’s National Zoo, the longest line forms outside the Reptile Discovery Center. People wait patiently for the chance to see lizards, tortoises, crocodiles—and snakes.
Yes, people line up to see snakes. And not just in Washington. Studies at other zoos have found that reptiles, including snakes, rank among the most popular exhibits. “There is a real dichotomy,” says the Zoo’s interim herpetology curator, Jim Murphy. “You might hate snakes, but you can’t stop looking at them.”
Sinaloan milksnake (Jessie Cohen/NZP)
Of nearly 3,000 snake species, only about 450 are venomous. Yet few other living things arouse such fear and loathing among humans and our closest primate cousins.
Ophiophobia, or fear of snakes, runs deep in our ancestral roots. “In Africa, where hominids evolved, venomous snakes are common, and there are no simple visual rules for discriminating harmless from truly dangerous species,” Murphy and colleagues write in a paper on snake phobia. “Thus detecting and indiscriminately avoiding all snakes was probably favored by natural selection.”
Lynne Isbell, an anthropologist at the University of California, Davis, goes a step further. She maintains that proximity to snakes was responsible for advanced brain development in our branch of the evolutionary tree, which includes Old World monkeys and apes. Specifically, she says, the need to recognize dangerous snakes led to superior vision, including forward-looking eyes, depth perception, and the ability to distinguish color.
Green tree python (Mehgan Murphy/NZP)
Not coincidentally, it is these same primates that exhibit the greatest fear of snakes. Results from some 200 years of research indicate that in many primates this fear is innate. Charles Darwin described his own experiments, which demonstrated that a snake elicited a much stronger fear reaction in chimpanzees than a turtle did. Another researcher noted that chimps reacted with fear even at the sight of earthworms or parasitic worms passed in the feces of one member of the troop, perhaps because the cylindrical shapes were reminiscent of snakes.
Even the largest apes are terrified of snakes. Jim Murphy tells the story of Bushman, a huge male gorilla that lived at Chicago’s Lincoln Park Zoo in the 1940s and 1950s. One day, Bushman escaped from his cage and wandered through a service area into a kitchen, where he began to wreak havoc. “Keepers tried everything to entice him out, but nothing worked until the herpetology curator suggested putting a live garter snake under the door,” Murphy recounts. “Bushman saw the snake, and literally ran down the service corridor and back into his cage. He had been caught in the wild as a baby and so probably had very little contact with snakes. Yet a very small, harmless snake terrorized him.”
Vervet monkeys, native to southern and eastern Africa, can discern the specific danger posed by different species of snakes and alert other members of the troop accordingly. They emit alarm calls to warn not just of pythons, which prey on vervets, but also of venomous snakes such as mambas and cobras, which are too small to eat a vervet but are still potentially dangerous. Harmless snakes and lizards elicit no alarm calls.
People and Snakes
Research in people is less clearcut, but most experts agree that, at the very least, we are hard-wired to quickly learn to fear snakes when presented with negative images. Studies showing that very young children can easily recognize a snake in a picture of flowers suggest we are innately hypervigilant about snakes, says Gordon Burghardt, professor of psychology and of ecology and evolutionary biology at the University of Tennessee, Knoxville.
Children, however, are often fascinated by snakes until their interest is quashed by adults.
Burghardt, who visits schools with live snakes, says, “Kids are often really interested and want to hold them. It’s the teachers who are ambivalent. I have to cajole them to hold the snakes and show the students they’re not afraid.”
Common king snake (Jessie Cohen/NZP)
During his years at the Dallas Zoo, Murphy often saw kids at the beginning of a visit to the reptile house who commented that they liked the snakes and thought they were beautiful. “Parents would say, ‘No, they’re ugly, you have to be careful of them,’” he recalls. “The conversations between kids and parents got shorter and shorter, and it was a rare kid who would go through the whole place still defending his interest in snakes.” Even without such adult prodding, research shows, many kids naturally become more leery of snakes as they get older.
For zoos, the challenge is acquainting visitors with animals that many people instinctively dislike. While it may be next to impossible to desensitize the truly phobic, education can help calm fears and instill some appreciation of snakes in many zoogoers.
After a study at the National Zoo in the 1980s revealed that visitors spent an average of eight minutes viewing exhibits in the reptile house and a mere eight seconds looking at any individual exhibit, the Zoo opened HerpLab, equipped with hands-on activities and live animals. Subsequent installation of interactive learning modules significantly increased the amount of time visitors spent viewing exhibits. Today, the Reptile Discovery Center includes a resource room, reminiscent of the old HerpLab. Staffed by volunteers, it features live snakes and lizards as well as skins, bones, and other objects to touch.
Other zoos have also tried to assuage visitors’ fear of snakes. Back in the mid-nineties, Murphy and colleagues designed an exhibit called the Fear Zone for the Staten Island Zoo in New York. Amid calming colors and music, visitors circulate through exhibits that debunk myths about snakes. At the end, they can choose to meet a volunteer with a live snake or leave through another exit. About 90 percent choose to meet and even touch the snake—proving, Murphy says, that “the single best way to engage visitors is with a live snake, no question in my mind.”
Can Snakes Survive?
Those who take the time to get to know these intriguing creatures learn that, despite a very simple body plan, snakes have adapted to live in all sorts of environments. They also help maintain the natural balance within an ecosystem, keeping populations of rodents, amphibians, lizards, and birds in check. Unfortunately, despite their versatility, snakes are in trouble in the wild.
A recent study by British researchers showed an alarming decline in snake populations in widely different parts of the world. The scientists monitored 11 species of snakes in France, the United Kingdom, Nigeria, and Australia. They found that two-thirds of the populations studied had collapsed, even in protected areas. Moreover, populations showed no signs of recovery in more than a decade.
The British investigators offered no clear reason for the decline, but other research points to troubling environmental concerns. Karen Lips, a biologist at the University of Maryland, reports that in areas of Panama where the fungal disease chytrid has destroyed amphibians, snake populations have also crashed.
Gaboon viper (Mehgan Murphy/NZP)
Meanwhile, snakes are losing prey, such as lizards. Researchers at the University of California, Santa Cruz, have concluded that climate change is killing off some species of lizards that are active during the day. Rising temperatures force the lizards to spend more time seeking shelter from the sun to prevent overheating, leaving less time for them to find a mate or forage for enough food to support reproduction. Some 20 percent of all lizard species could go extinct by 2080, the scientists predict.
Erie water snake and Florida’s indigo snake are gaining some public support and protection, and some snakes are beginning to find their way onto states’ endangered species lists. But, say Burghardt and Murphy, the best hope for the next decade or so is to focus attention on ecological hot spots inhabited by charismatic mammals, such as tigers, rhinos, elephants, and great apes. Snakes, by default, will benefit.
Over the long term, say Burghardt and Murphy, saving snakes may depend on “reinstating a certain reverence for them” as part of the natural world—of creation, if you will. As such, they argue, snakes are worthy of our stewardship. Snakes, they conclude, are here for a reason, and “as representatives of Earth’s incredible diversity and important pieces of its ecological puzzle, certainly deserve to be conserved, regardless of human attitudes toward them.”
—Freelance writer PHYLLIS MCINTOSH is a veteran Zoo Volunteer
If you have a comment about Smithsonian Zoogoer magazine, please email it to us.Smithsonian Zoogoer 39(5) 2010. Copyright 2010 Friends of the National Zoo. All rights reserved.