How Do You Save an Elephant’s Tusk? Ask a Materials Engineer
Bulwagi, a 35-year-old male African elephant that lives at Birmingham Zoo, came pretty close to losing his tusk after a deep crack appeared in the ivory. But advanced composites saved the day.
The team applies the vacuum pump during the procedure. Image: Katherine Shonesy/UAB
Every day in Africa, approximately 96 elephants are killed for their valuable ivory tusks.
In Alabama, however, one lucky elephant just managed to keep his tusk thanks to an engineer who normally works on bridges and airplanes.
Bulwagi, a 35-year-old male African elephant that lives at Birmingham Zoo, came pretty close to losing his tusk after a deep crack appeared in the ivory. Small cracks in tusks are fairly common—elephants use their tusks for robust activities such as defense and digging—but this one was pretty deep. If left untreated, the tusk could have become infected, just like a human tooth, which would have threatened Bulwagi's health and required the removal of the entire tusk.
The zoo spent the past few years trying to save the tusk, with no luck. At one point in 2014 they tried applying a cast, just like you'd get for a broken arm. It didn't last long.
"He took it off almost immediately," said Richard Sim, associate veterinarian at the zoo. "He actually ate it." Attempts to fill in the crack with dental cement also proved fruitless.
With the crack slowly growing worse, the zoo decided to do something that has historically been done to help save other elephants' tusks: place a metal ring around it, kind of like when your dentist puts a crown on a broken tooth. That, they hoped, could keep the crack from continued spreading. They approached the University of Alabama at Birmingham School of Engineering to fabricate a ring that could help Bulwagi keep his tusk.
"I asked if this was the standard," said Dr. Brian Pillay, director of UAB's Materials Processing and Applications Development Center, who had never worked with elephants before. He found out that a metal ring would typically require several screws to be driven into the ivory to hold it in place. "It's got to be a very heavy solution, not to mention it would be pretty ugly," he said.
Pillay wondered if anything else could solve the problem. "I do a lot of work in composite materials," he said. "We're constantly replacing metals with lighter and more efficient structures." He asked the zoo if they would be open to new materials and new technologies. They said yes.
Pillay and his team of students settled on a composite fiberglass and carbon-fiber band and resin. "The materials we've been using are the same materials we in bridges, airplanes, cars, stuff like that," he said. Although commonly used, Pillay said the materials had never been applied to a biological solution before.
Developing the solution took a few months of testing and preparation and practice on PVC piping. "The tusk is not a uniform cross-section area," Pillay said. "It tapers. Trying to do it within the constraints of not stressing the animal too much was a big challenge."
Finally it was time. On November 5 of last year, Bulwagi's handlers called him up to the bars of the zoo's elephant barn, the same place where he also receives baths and regular medical treatments. On cue, he positioned his tusk through the bollards and the two-hour procedure began.
Under Dr. Pillay's guidance, zoo staff placed layer after layer of carbon fiber on the tusk, surrounding the crack. Under typical industrial solutions, they would have painted each layer with an epoxy to create a good bond. "That would be too time-consuming for working with a live animal," Sim said. Instead they used a vacuum pump to suck the epoxy out of a bucket and then inject it into the carbon fibers, which quickly absorbed the materials and in just three minutes created a hard, strong, impermeable shell.
"All credit to the handlers, they kept him still enough long enough for us to be successful," said Pillay.
Three months later, Bulwagi, his tusk, and the industrial wrap are doing well. "I don't think he notices it's there," Sim said. "He doesn't give it any great attention." He reports that the wrap has held up to Bulwagi rubbing it against things and shows no signs of falling off.
Unfortunately, the solution may have come too late for Bulwagi. Sim reports that they think the tusk did indeed become infected before the procedure. They're monitoring him in case further action is necessary.
Even if Bulwagi does not ultimately get to keep his tusk, Sim and Pillay said they hope the solution could help other elephants in the future. Both report that other zoos have inquired about the process. Pillay's students are still working to refine the materials that they used and he said he hoped to possibly write a manual that would allow veterinarians around the world learn how to do this process on their own. "Then we could help elephants not just in the zoo but in the wild rather than have their tusks removed," he said.
He added that after his daughter heard about the process she asked, "Why don't you do something to make the tusks useless to poachers?" "I wish I could," he replied.
Sim, for his part, thinks the process would have less potential in the wild, where animals with broken tusks would need to be anesthetized. He did see some possibility for helping other species with hard external structures, such as turtles with broken shells, although that's not something they have explored to date.
Both Sim and Pillay seemed energized by the project, which combined both of their skill sets to create a new solution. "We were able to come up with a new idea that help the elephant and make it happen," said Sim. "That made for the cool intersection between the industrial engineering part of this and the biological husbandry. It's been fun to work on."