The 20th-Century Ark : At San Diego’s Center for Reproduction of Endangered Species, Scientists Battle the Fall of the Wild

Ilonkah, one of the new cheetahs for the San Diego Wild Animal Park, had injured its paws on the plane flight from South Africa, and now it lay sedated on an operating table in the San Diego Zoo’s veterinary hospital.

Its injuries turned out to be slight. But the image seemed to haunt Donald G. Lindburg, a behaviorist with the zoo’s Center for Reproduction of Endangered Species.

“Imagine how you’d feel if that were the last living cheetah,” he said to a visitor. “It would be a nightmare, wouldn’t it? Well, at CRES that’s what we’re trying to avoid.”

For the world’s threatened species, scientists such as Lindburg and the other staff members at the center may be the last, best hope. Since its creation in 1975 by the Zoological Society of San Diego, this life-science think tank has become a leader in research on the birth and health of exotic and endangered creatures.

Zoological authorities estimate that as many as three-quarters of the world’s animal species will vanish in the next 25 years. The International Union for the Conservation of Nature and Natural Resources, an ecological monitoring organization based in Switzerland, recognizes 1,000 endangered species, which it defines as those within 15 years of extinction.

Unless this trend is reversed, the world could lose animals as familiar as the elephant, or as rare as the Komodo dragon, a giant lizard whose ranks have thinned to about 6,000. As civilization and industrialization expand, with rain forests transformed into farmland and plains into cities, animals are being crowded out of existence. A time may come when most people will never see an animal in the wild, because most animals will exist behind fences.

To prevent such a bleak future, zoos have in recent years strengthened their research wings, and the San Diego facility is widely recognized as the largest and most ambitious of its kind. Only the London Zoo is comparable in both staff size and multidisciplinary approach. CRES research projects have included the creation of a “frozen zoo” stocked with animal cells, the development of an aluminum water bed used to comfort pregnant mammals, and the installation of hormone pumps in animals who fail to breed. At the same time, CRES has produced a torrent of scientific papers, on subjects ranging from iguana hormones to the sexual habits of gorillas.

Most of its research takes place in a two-story Spanish-style building wedged between the zoo grounds and the Old Globe Theater in San Diego’s Balboa Park. (The Wild Animal Park, the zoo’s rural “sister campus,” is in Escondido, 35 miles to the north.) In the ‘20s, the building served as the zoo hospital, but the veterinary staff abandoned it long ago for state-of-the-art facilities nearby.

The center, meanwhile, has turned the building into an intellectual MASH unit pursuing studies in virology, pathology, genetics, endocrinology and behavioral science. Somehow, the staff of 25 gets its work done in cramped offices built in what used to be hallways and laboratories that once were closets. Studies of animals decorate the walls, including a chart showing the proper way to give mouth-to-mouth resuscitation to a lizard. Arden Bercovitz, an avian reproductive specialist, maintains a laboratory and office in a converted kitchen. Barbara Durrant, a reproductive physiologist, works in what used to be the morgue. Receptionist Sharon Dinwiddie, who sits in front of a sign reading “Warning: Attack Secretary,” describes the atmosphere as “permanently intense.”

The staff was, for the most part, assembled by Dr. Kurt Benirschke, a pathologist who retired last year after a decade as the zoo’s director of research. Benirschke, whose background is in the study of human reproduction, initially built the staff to support the zoo’s captive breeding programs. Most of the scientists were lured from research programs at UC San Diego, with others recruited from Harvard, UCLA, UC Davis and North Carolina State.

The center operates on an annual budget of $1 million, with $800,000 coming from the zoo’s operating budget and the remainder from donations and fund-raisers. A drive to raise $20 million, started by Benirschke and the zoological society in 1979, continues. Its goal is to endow a series of permanent research chairs for the center and improve its facilities.

Though billions have been spent on animal research in this country, almost all of it has gone toward the study of animals we eat or keep. Almost every study performed at the San Diego center breaks ground in its field, simply because most of the field has yet to be created.

For obvious reasons, this is not a center for surgical experiments or studies on how to fatten livestock. Most of its work is physically valuable to the animal it saves and no one else. An endangered species profits little from experiments that kill it.

The center emphasizes “non-invasive” research whenever possible, without knives or needles. When it needs a specific blood or tissue sample, the staff tries to wait until such an animal visits the zoo hospital, perhaps because of quarantine or injury.

Bercovitz, for example, has spent four years refining a procedure to determine the sex of birds without depriving them of blood or skin. His work--based on the discovery by former CRES endocrinologist Bill Lasley that manure can be tested for hormones--has helped solve a basic problem for veterinarians. With about one-third of the world’s birds, gender cannot be ascertained visually, and taking blood samples to determine sex can be fatal. Until recently, in fact, it was common for a zoo to discover during an autopsy that a mysteriously infertile female was actually a male, or that two unproductive mates were of the same sex.

“There are roughly 8,600 species of birds,” Bercovitz says, “and of those maybe a dozen have been studied in any scientific detail. We know a lot about turkeys, chickens, ducks, quail--things that we eat or eat from. But to say all birds are like chickens is to say all humans are like laboratory mice.”

The scope of Bercovitz’s work becomes obvious as soon as he opens the refrigerator in his tiny office. It is filled with vials containing hormone samples drawn from the droppings of falcons, cranes and a variety of other species. The collection includes hormone samples from almost all the 26 remaining California condors.

But the most famous freezers at the center are in a room down the hall from Bercovitz’s office. The “frozen zoo,” also known as the 20th-Century Ark, is a pair of three-foot-square metal tanks connected to a supply of liquid nitrogen. Inside the tanks are steel racks filled with semen, egg and tissue samples from roughly 350 endangered species. The liquid nitrogen maintains the tanks at 385 degrees below zero Fahrenheit. The cells inside are suspended in a scientific time warp--frozen alive and held in indefinite limbo until they are needed for research, or implantation in a womb.

A fertilized egg from this icebound menagerie could someday be used to revive an extinct population, if successfully implanted in a surrogate mother. Typically, however, the samples are put to less spectacular uses, contributing to studies of aging, evolution and artificial methods of fertilization and insemination. Occasionally, samples are sent to other zoos. The Bronx and Cincinnati zoos have similar collections, but San Diego’s was the first and is the most extensive.

The freezers are a favorite stop on tours of the building, and the fog that pours forth when the lids are removed is dramatic and seems mysterious. But in that sense, they are misleading; the rest of the organization looks nothing like a science-fiction movie set. On most days the building is a warren of closed doors, with the staff buried under lab work, grant requests and studies that can continue for years.

Virologist Michael Worley, for example, has spent much of the last four years examining the blood of leopards in a laboratory on the first floor. Snow leopards, it seems, are vulnerable in captivity to a liver disease apparently caused by a hepatitis virus. Worley concedes that finding the virus has become an obsession, driving him to seven-day workweeks and straining his patience in the lab.

“I realized a little while ago that I’d been thinking of leopards ever since 1981,” he says. “We’ve had a lot of little breakthroughs, but nothing major for a while.”

The breakthroughs, when they come, can seem obscure to outsiders.

“You’ll never see a headline reading ‘Pygmy Chimp Sperm Penetrates Hamster Egg,’ but it was a very big deal around here,” says Durrant, the resident expert on artificial insemination and in-vitro fertilization. “You say ‘animal research’ and people think we’re in here doing all kinds of outrageous operations. But we’re not. We’re really very conservative.”

More often than not, the moments of drama are unpleasant ones. Marilyn Anderson, the zoo’s director of pathology, has worn a black armband since a wild California condor died in January at the Wild Animal Park. Like most of her colleagues, Anderson believes that the condor died because of complications from years of lead poisoning and also because it was brought in for care too late; efforts to bring the bird in earlier had been thwarted by conservationists.

Some conservation groups, including the National Audubon Society, have fought to keep condors in the wild because they believe that field study is the best way to learn about them and because, says Ruth Norris, an Audubon Society spokeswoman in Washington, of the fear that if the condors are removed from their habitat, the habitat itself will disappear.

“It was really awful when that (condor) came in,” says Lindburg. “At times like that you wonder if you’re watching a species go extinct before your eyes.”

Other animals, such as the Arabian oryx, have been luckier. The horned oryx, an antelope that in profile looks something like the mythical unicorn, had once seemed doomed in the wild and was dangerously inbred in captivity. Geneticists at the center helped reverse the inevitable by learning to pair the animals according to their chromosomes.

Today, a picture of an oryx hangs over a desk in the office of Oliver Ryder, the resident geneticist.

“That picture was taken in the Middle East, but look at that scratch on the horn,” Ryder says, leaning forward and tapping the picture with his pen. “That’s our mark, that scratch. It tells us that that oryx was born in Escondido (at the Wild Animal Park). That’s the easiest way I know of to explain what I do.”

For John Phillips, an environmental physiologist, the explanations come during a tour of a small shed a few yards from the center. Used for studies of fertility in reptiles, it contains several sets of lizards implanted with hormone pumps. Staff members refer to them by such pet names as Mr. and Mrs. Big Guy, Stumpy and Weird Al Yankovic.

“We had a couple named Mr. and Mrs. Mellow, but Mr. Mellow died a while back,” Phillips says. “That was pretty depressing.”

The research center uses several official arguments to justify its work. In general, these revolve around the unknown global side effects of mass extinctions; the possibility that animal research might benefit human medicine and biology; the moral imperatives, and attempts to keep from cheating future generations--of animals and humans.

But to Phillips it somehow seems more elemental.

“When the cameras roll in here someone always asks us, ‘Is it worth it?’ which is frustrating. People who ask us those questions will never understand the answers. They’re almost not worth talking to. What we do is really very basic.”

The cheetah is a case in point. The animal, whose name is Hindi for “the spotted one,” is finding it hard to thrive in its remaining African habitats, having long ago vanished from breeding grounds in Asia and Europe.

Today, though 10,000 to 25,000 cheetahs are said to remain in the wild, much of that wild is disappearing because of human encroachment. In Namibia, cattle ranches are increasingly swallowing up the animal’s habitat, and cheetahs are frequently shot because they are a danger to livestock. By some accounts, African cheetahs outside of zoos may vanish within a few decades. In captivity, the big cats have fared poorly, breeding sporadically and behaving sluggishly.

Because their extinction seems imminent, the arrival of seven cheetahs, acquired from a game preserve in South Africa, caused a stir at the center. Worley, the virologist, was anxious to obtain a blood sample to aid a study of feline infectious diseases. Durrant, the reproductive physiologist, needed a sperm sample for the frozen zoo. And Phillips, an environmental physiologist, needed measurements of limbs for comparison with the limbs of captive stock.

Lindburg needed a rest, among other things. He’d been watching over the cheetahs for several weeks now, and when the quarantine was over he’d oversee their placement in the Wild Animal Park.

“Then we’ll see them run,” he said. “Cheetahs are amazing when they run.”