Zoo Tales: Snakes alive!

May 29, 2008 11:25 am

— Snakes have scared and fascinated us throughout the ages and have led to countless superstitions and religious myths. Throughout the year, the N.C. Zoo tries to educate visitors and quell some of those myths and fears with snake-related games, keeper talks, exhibits and hands-on demonstrations about snakes.
A typical demonstration might focus on the zoo's efforts to track and study indigenous snakes on the zoo property through the use of tracking transmitters on the animals. During the demonstrations, keepers show visitors how to identify and co-exist with snakes, including how to move them when necessary.
"People don't seem to want to take the time to determine if a snake is venomous," said Mark Lewis, keeper and herpetologist at the N.C. Zoo. "To most people, it's just easier to dislike them all."
This dislike is often due to ignorance of the important part snakes play in the larger ecosystem, and sometimes it's incorrect information about snakes that is passed down from generation to generation.
"People don't understand what rodent controllers snakes are," Lewis said. "Most snakes can eat small mice and other small rodents, but it takes a large snake to eat rats and large rodents."
Although labeled as slimy, snakes actually have very dry skin. They don't even have mucous glands to produce "slime." Scales prevent the snake from drying out and aid in locomotion.
Another myth is that the venom of young or small snakes is not as toxic as that of an adult of the same species. Actually, the venomous bite of small, juvenile snakes may be more dangerous than an adult's. A snake's venom gland must replace venom lost with each bite, which takes time. For this reason, adult snakes learn to conserve venom. Juveniles often have not learned this and discharge their venom completely with each bite.
Any snakebite, whether venomous or not, should be considered a medical emergency; however, most are not lethal. According to the American Red Cross, about 8,000 people a year receive venomous bites in the United States; about 12 of those victims die. A venomous snake does not necessarily inject venom with each bite and can vary the amount of venom injected with each bite.
Venom is actually modified saliva, used both to capture and kill prey and then to digest the prey. Venoms are primarily either hematoxic, which means that they primarily affect the blood, or neurotoxic, which means that they attack the nervous system and brain. Snake venom is made up of about 20 different enzymes. Each species usually has 6 to 12 of these enzymes, which determine the snake's toxicity and whether it is primarily hematoxic or neurotoxic.
Unfortunately, many people believe that the only good snake is a dead snake. Seeing a snake is no reason to kill it. Most snakes are more afraid of humans than humans are of them. Snakes are here for a reason; they serve an important role as both predator and prey in complex food chains. Killing a snake and breaking the natural food chain can affect all the other creatures in the chain.

Tom Gillespie lives in Trinity and is a journalist and public affairs specialist at the N.C. Zoo. For more information on the zoo's plant and animal collections, special events and education programs, go to their Web site at www.nczoo.org