Brian Gratwicke
You’ve got your Ozark hellbenders, amphibians found exclusively in the backwaters of Missouri and Arkansas, and you’ve got your eastern hellbenders, which are found in the shallow, cold-water streams of the Appalachians through Tennessee. Examples of both types of the giant salamanders are well represented at the Saint Louis Zoo’s Ron Goellner Center for Hellbender Conservation, where 105 hellbenders constitute the largest controlled population in the world.
But if little Johnny or Jenny wants to visit the hellbenders on their next trip to the zoo, they’ll be in for a touch of disappointment, as the collection of hellbenders is on-site, but off-exhibit, except for one very small, lightly inhabited exhibit in the herpetarium. While they are not serving any public desire to see to the greatest-named animal in the world in great numbers, the zoo’s hellbenders do serve another purpose: round-the-clock study for conservation.
Over the last three decades, scientists have noticed significant patterns in the way hellbenders have reproduced and in the way the species has shifted locations. To monitor the way their freshwater climes are changing, the zoo is working with the Missouri Department of Conversation and the U.S. Fish and Wildlife Service to isolate what those changes might be and what impact they might have on humans, even as they slowly return hellbenders to the wild. So if, say, chemical contaminants are getting into the hellbenders’ waterways, “they’ll effect us eventually as well,” says Jeff Ettling, the Saint Louis Zoo’s curator of herpetology and aquatics.
Raising hellbenders from eggs to young adulthood will be the next step in the process. “To breed them in captivity is something new,” Ettling says. “We are fine-tuning the parameters to make that happen.”
As the zoo has built its hellbender research base, a good-sized corner of the 83-year-old herpetarium’s basement has been converted into something very high-tech. A 32-foot-long mock stream is segmented in half, allowing the animals 64 feet of swimmable real estate. The habitat can be changed in multiple ways; for example, to track the way hellbenders move and mate, sprinklers replicate rain showers. “We don’t know if rain effects reproduction habits,” Ettling says, “but this way it’s as close to their realistic environment as possible. If it’s raining in the Ozarks, we can turn on the sprinklers here.”
Video surveillance is another part of the technology. Student interns are frequently given the chore of watching time-lapsed movements of the hellbenders through the mock stream, while Ettling also can see them from his computer at home if he wishes.
At this point, eight hellbenders are in the mock stream while dozens more inhabit tanks around the room. A neighboring room is being prepped for additional hellbender research, with some large tanks growing the hellbenders’ favorite foodstuff, crayfish, which makes up 90 percent of their diet. By spring, two outdoor, enclosed streams will be opened, as Ettling explains in this video. They, too, will be closed to the public.
“Over time, studies have shown that entire segments of their population have shifted,” says Ettling. “Something over the last three decades has been going on… They’re having trouble reproducing in the wild and youngsters being found are few and far between. There’s a great effort going into finding out why.”
