In a nondescript building a dozen yards from North Parkway, Dr. Andy Kouba gives visitors a look at the "frozen zoo." Unlatching the lid of an insulated container the size of a beer keg, he gently lifts out a stainless-steel rack of test tubes suspended in liquid nitrogen. Preserved at minus 196 degrees Fahrenheit, these hold sperm collected from endangered species around the world. Though it sounds like science fiction, these tubes in the research laboratory of the Memphis Zoo may be the last chance of survival for many of our planet's animals.
"This is the CSI lab of the animal world," says Kouba, the zoo's director of research and conservation. "We are at the point now where we can reproduce endangered species and introduce them back into the wild."
Kouba, who holds a Ph.D. in animal science from the University of Florida, came to Memphis in 2001 to start up the zoo's new research program. His team, which includes three full-time staff, post-doctoral fellows, and undergraduates, works primarily with the zoo's giant pandas, elephants, and certain species of reptiles and amphibians.
"But if one of the curators says the antelopes aren't breeding," he says, "we try to figure out why." Some animals are simply "mate-incompatible" — they don't get along with each other. "In nature, they have opportunities for selecting their mates," says Kouba, "but since zoos often group just two or three animals together, they can be as picky as humans and might not like each other."
Other factors include light, temperature, humidity — all sorts of things. "What we do is address those aspects," says Kouba, "before we intervene with more invasive technology — artificial insemination."
That work usually begins in the lab, where technicians examine an animal's urine and bloodwork to determine when the female of the species is likely to conceive. For the larger animals, the next step can be complicated. The Memphis Zoo, for example, has no male elephants, so elephant semen has to be ordered from other zoos.
"People always ask how much elephant sperm is required," Kouba laughs, "and I always say, just one . But we increase the odds by putting in as much as we can."
We'll spare readers the details of how elephant sperm is collected, but the zoo works with German specialists to artificially inseminate the female. "They use a catheter to place the sperm directly into the uterus, which is about nine feet from the entrance."
Last year the female elephant Asali gave birth to a baby — one of the few in this country reproduced artificially. Unfortunately, the calf was accidentally crushed by the mother two days later, but Kouba is encouraged by signs that Asali may be ready to conceive again.
This work is critical because elephants' natural habitat is being destroyed and zoos sometimes provide their only haven. Even that is threatened: "Zoo elephants are aging, and studies show that we don't have enough to sustain a population in the U.S. unless we step up this program. In fact, in the next 30 or 40 years, elephants could become extinct in the U.S."
Some of the creatures the zoo helps are considerably smaller. Kouba shows off Waffles, a nine-year-old Mississippi Gopher Frog. "This is the most endangered amphibian in the U.S.," he says. "There's probably only 50 left in the wild."
Waffles was collected in 2001 by the Detroit Zoo. "They shipped her here to see if we could get eggs from her before she passes on. She's an older frog so she represents a genetic lineage that is no longer available."
Breeding frogs is considerably easier than elephants and other mammals, since it mainly involves mixing eggs and sperm in a Petri dish and waiting for the results: tadpoles.
Kouba recently returned from Wyoming, where he released endangered toads born in Memphis. "Most zoos can't say they release many animals at one time," he says, "but we released some 2,000 toads."
With those successes come setbacks. After the baby elephant died last year, "It took a long time to collect ourselves and rebound," Kouba says. "But we realized we just have to start all over again, because it is so extremely important for the species."
