There’s a room on the second floor of the old San Diego Zoo hospital where a person can feel like a god. Two metal chests that look like overgrown dishwashers stand against one wall of the cluttered quarters. Lift one of the lids and a cloud of snowy vapor billows up from the depths, where tiny plastic vials are frozen to 321 degrees below zero Fahrenheit.
The containers hold the seeds of pigmy chimps, jaguars, spectacled bears, and more; someone with an imagination has hung up a sign reading, “Frozen Zoo — Twentieth Century Ark.” A person can tower over the chests, with this multitude of creatures at his fingertips, and envision creating worlds; populating continents.
Kurt Benirschke looks forward in the future to using the frozen cells to fill zoos that would otherwise stand empty. Benirschke is the San Diego Zoo’s director of research — but when he talks about his work, he doesn’t sound very godly. He expresses frustration; even a little bitterness. Benirschke is a medical doctor; research into human reproduction was once his specialty, so he knows what can be done with a freezer full of human sperm. Technicians can make it and inseminate a woman at precisely the right moment so that nine months later she delivers a healthy baby.
Last year’s birth of the celebrated English “test tube” baby Louise Brown marked an even greater milestone in the understanding of human reproductive physiology. In contrast, the chest full of animal cells is still practically useless. “The problem with artificial insemination is very complicated. It’s very easy to talk about. It’s very difficult to do. Because it’s much more than having the semen available. You must know when the female ovulates precisely, because the egg doesn’t live more than two or three hours,” Benirschke says. “And it’s not known when to inseminate an elephant. It’s not known when to inseminate a kudu or an impala or a gorilla or a chimpanzee.” A few years ago, Benirschke weighed the knowledge of humans versus the knowledge of animals and decided the imbalance simply wasn’t fair. And so he says, “I’ve given up on human life.”
The doctor is a slender, soulful-looking man of fifty-five; his eyes are deep-set, and his voice still reflects remnants of his native German accent. He works in an old-fashioned office filled with wooden bookshelves and light from three large windows. It’s in the old zoo hospital, located in one of the farthest reaches of the zoo grounds, much closer to the burned shell of the Old Globe Theatre than to the paths filled with chattering children and tourists. His manner is gentle, noncombative.
He talks about his commitment to animal reproduction in personal terms. “We have too many people, and we’re killing the wildlife,’’ he says flatly. “I feel very strongly that the reason why we have so many people is because we understand human reproductive physiology. . . . I feel it’s time we translate this to the other species that we ’re in the process of rubbing out.”
Benirschke began directing the zoo’s research almost exactly five years ago, when the department included only him, two lab technicians, and a secretary. Today a team of twenty-one people (including two graduate students) is working on the biggest program of exotic-animal research in the world. Benirschke doesn’t get all the credit for building up that program; part goes to the zoo’s board of directors and part also goes to the mortal crisis now imperiling zoos everywhere, the situation which galvanized the board into taking some action.
Quite simply, zoos need animals and the animals are disappearing from the world. As humans have multiplied and spread out over the globe, they’ve cut down forests, flooded wilderness areas by building dams, unleashed hordes of cattle — in short, they’ve destroyed a vast range of animal habitat, as well as having killed them directly for meat, feathers, pelts, and souvenirs. Zoos have captured them for display, but Benirschke says studies have shown that zoos account for only one or two percent of all wild animals imported into this country. In any case, more than 200 species have died out completely since the early 1600s, with the mortalities increasing exponentially. Thus, says Benirschke, today “you couldn’t buy an Indian rhinoceros from India. There are no more rhinos in India. ’’ But the force which really put pressure on the zoos was ironically the explosion of conservationist consciousness during the 1960s. The protective legislation which grew out of that consciousness — the U S. Endangered Species Act of 1969, the CITES treaty which now includes almost sixty nations worldwide, national laws which have prohibited the removal of animals from the wild — choked off the supply of zoo animals far more dramatically than the dwindling natural populations. “Ten years ago you could more or less write an order for a giraffe and you could buy one,” says Benirschke. “That would be very difficult now. The laws of importation, and quarantine, and guaranteeing that they're disease-free make it very expensive to buy yourself a giraffe from Africa.”
In spite of the growing crisis, some zoo people nonetheless buried their heads in the sand. “After all, many animals have great longevity,” Benirschke says. “You take gorillas which live thirty to forty years. If you have some youngster gorillas, for the next forty years you can be all set, barring any catastrophe or disease and so on. A fifty-year-old zoo director may not feel the pinch because he'll be retired by then.” Benirschke also thinks of the scientific research community, which until last year blithely imported 60,000 to 70,000 rhesus monkeys a year for purposes of experimentation. “For years some of us had told the government that if people want to have rhesus monkeys, they should be breeding their own.” The warnings went ignored until last year, when the government of India suddenly cut off all monkey exportation. “And now they’re asking, ‘Where are we going to get them from?’ ”
Still, other zoo people saw the future clearly: “If zoos are going to exhibit fifty years from now, the animals will have to be zoo-bred,” Benirschke puts it. Among those who recognized that were the directors of the San Diego facility. If nothing else, the local zoo’s size made it a natural candidate to take the lead. The San Diego Zoological Society’s budget now is about $26 million, compared to only about $12 million at the Bronx Zoo; $8 million at Chicago’s Brookfield Zoo, $7 million at the National Zoo. and a paltry $3 million in Los Angeles. So the San Diego Zoo directors decided, Benirschke says. “If the San Diego Zoo does not breed its animals, in the future there will be no San Diego Zoo as we know it now.” So the zoos should breed their animals. Why not? What’s the problem?
Indeed, there is no problem with creatures such as the mandrills — large, gregarious, baboon-type primates which come from the rocky terrain of West Africa. Mark Bogart, the zoologist who’s in charge of the zoo’s primates, says you can put mandrills like Dennis and Lady and their fellows in very ordinary cages like those in the zoo’s “monkey mesa,” and most mandrill mommas will faithfully produce a baby a year, no muss, no fuss. Moreover, Benirschke says today almost every zoo animal has been bred in captivity at some time, somewhere. But for every one that reproduces as easily as the family dog, one can find examples like that of the lion-tailed macaque. Less than a thousand of the small black and gray monkeys remain in their native habitat, a few limited forests in the south of India. About 300 others, including many youngsters, live in zoos worldwide; the San Diego Zoo has about seven, including two females of breeding age. Only two or three baby lion-tailed macaques have been born here in the last few years, and the record elsewhere has been similarly dismal. Fewer than a quarter of the adult females have produced an infant yearly for the last several years, and more than fifty collections haven’t produced any babies in the last decade.
Furthermore, when zoos make a commitment to getting all their animals by breeding them, they confront other problems besides simple reproductive failure. You need a certain critical number of animals in a breeding population for that population to sustain itself. Thus, for some animals, like the pigmy chimpanzee, the problem isn’t breeding, but breeding enough. The research director says a few pigmy chimps remain in the Congo, but they’re gradually being wiped out, and only thirty-two of the animals live in captivity. Benirschke has a poster of the animals hanging in his office; they’re the symhpl for the international conference on breeding being held at the zoo this week, and Benirschke admits that to his way of thinking, they’re “the most precious species. . . . They’re the most intelligent primate. They’re the most humanlike in all major studies, much more than the regular chimpanzees or gorillas.” Pigmy chimpanzees are one of the most successful primate breeders in the zoo; Kakowet and Linda, the adult pair the zoo received in 1960, have produced eight offspring, six females and two males. But the parents are getting old now and soon the zoo will either have to breed the brothers and sisters or exchange some members of the colony with others of the twenty-two pigmies now living in Europe and America. Even that may not work. “These are very intelligent animals,” Benirschke stresses again. “They don’t necessarily mate with any broad that comes along. They form very strong pair bonds, and it may very well be that in ten years there will be no more pigmy chimps because they won’t dig each other.” Benirschke thinks it would be a crime "if the species that is most closely related to us just disappeared.”
Finally, even less severely depleted populations that breed relatively well confront a major problem in captivity: the need for genetic variety. It may be relatively easy to fly pigmy chimps between London and San Diego, but it’s terribly difficult to transport elephants and giraffes and tigers. No zoo on earth has the room to maintain self-sustaining colonies of all these larger animals; in fact, few can maintain large enough numbers of any kind to preclude genetic inbreeding. The obvious alternative is to ship around tiny bottles of elephant sperm and giraffe sperm and tiger sperm, like those stored in the liquid nitrogen coolers in the old zoo hospital.
Benirschke points out that artificial insemination techniques have been well developed for cows and horses and sheep and humans — all species linked to powerful economic interests. But the doctor explains, “Even relatively closely related animals differ in their reproductive physiology quite widely. The ability to make a diagnosis of ovulation or pregnancy or impending parturition is a case-by-case study.” The time and money needed to study ovulation in gorillas or any other wild animals simply has been missing in the past. No one has cared. In addition, the tools used to study reproductive physiology in humans and domestic animals don’t necessarily work very well with wild animals. It’s very easy to get a blood sample from a woman or from cows in pens, for example. But getting a blood sample from a wild animal usually requires immobilization, and Benirschke says, “Every immobilization by dart gun is a major undertaking and there are considerable risks. The animals don’t like to be shot. When you shoot ’em with a dart gun, they can go into a rampage; they can break their necks; they can fall and break their legs. When they get up again they can stumble and drown. To be sure, most often it works all right, but you don’t do it if you don’t have to.” To study reproductive physiology, you have to study hormones, and how else do you study hormones if not in the animal's blood? Bill Lasley discovered an alternative method by studying those junglefowl which roam the zoo grounds so freely.
A dozen years ago Lasley was teaching math and physical science to high school kids near Sacramento. Today he’s the endocrinologist — the hormone specialist — in the zoo’s research department. The career change took him through two veterinary schools and postdoctoral work in human obstetrics and gynecology, and finally brought him to the zoo’s staff seven months after Benirschke had taken over the directorship and the mission to transform the San Diego Zoo into a research pioneer. Lasley is a boyish type with a quick sense of humor. He says after his arrival, “I thrashed around a good bit. I would say I spent a good six months clucking.” The word is appropriate, since he finally began to think about the fact that the sex of as many as a third of the birds in the world can’t be identified on sight. Needless to say, if a keeper can’t tell the boy parrots from the girl parrots, he’s going to have trouble getting baby parrots. As rudimentary as that fact may be, Lasley says it has been a major problem in exotic-bird breeding. Cutting the birds open or drawing their blood often traumatizes them and warps their reproductive cycles, so Lasley began searching for alternatives. He.knew that female birds in general produce large amounts of the sex hormone estrogen relative to testosterone, while the opposite would be true for males, and thus Lasley and a technician, Nancy Czekala, began analyzing the droppings of the zoo’s junglefowl to see how they might reflect that fact.
Junglefowl males and females do look different, and Lasley and Czekala quickly discovered a critical pattern. When they compared the estrogen to the testosterone in any individual bird’s droppings, they discovered that the relative proportions revealed the bird’s sex.They confirmed the technique in a dozen more birds, including some not visually distinct, and then announced it to the world. In 1976 the discovery netted Lasley and his group the international Rolex award and a $26,000 prize, which Lasley donated back to the research department to fund a bird-sexing service that would aid breeders of endangered bird species worldwide.
Lasley, for example, tells how the United States Department of the Interior sent the lab samples from one endangered bird group which had bred very poorly, Puerto Rican parrots, less than.thirty of which may remain in the entire world. Using the information provided by the San Diegans, the government paired about a dozen birds, and Lasley says he’s heard that the colony has begun to produce offspring.
Since then, Lasley has extricated himself from the bird work to focus instead on primate urine. No one has any trouble telling male from female gorillas, or spider monkeys or chimpanzees, but Lasley figured the urine could help the zoo staff pinpoint ovulation and pregnancy in some of those animals while avoiding the trauma of taking their blood. To establish the technique, he and Czekala had the women in the zoo hospital donate daily urine samples (since human reproductive cycles have been studied so exhaustively). Soon Lasley found himself telling his co-workers exactly when their menstrual periods would start — and being right. He says it was relatively easy to transfer the concept to other primates; for example, you collect urine every morning from your friendly lemur, analyze it and chart the various hormone levels, and pretty soon you get graphs with evenly spaced peaks which reveal exactly when the creature is ovulating. The work has to be done with each species separately. Benirschke explains, “The hormones are bound and transported in a manner very different from species to species. And their degradation is very different from species to species. Therefore, their urinary excretion is very different from species to species. All of that needs to be correlated before you can say, 'This cougar is likely to ovulate tomorrow.’ ” In the last two and a half years, Lasley and his associates have managed to chart ovulation in at least fifteen different primate species, as well as in rhinos, bongos, okapis, and other animals.
They’ve racked up some dramatic individual successes. Lasley tells the saga of Georgette, the organ grinder’s monkey, physiologically normal, but apparently shy. Georgette lived in a harem with a male named Sampson, ‘‘a perky guy who really ruled the roost,” Lasley remembers. “The thing is that every time Sampson got close to mounting Georgette, another female in the group named Flossie [who had been hand-raised] would give a threat posture and for some reason, Sampson would go crazy and beat up Georgette! By analyzing her urine, we found that Georgette was ovulating normally, so what we did was to put Sampson and Georgette together alone eighteen days after Georgette’s previous ovulation. They really got it on. They were together three hours, and last Valentine’s Day Georgette had a baby boy. We named him Valentino.”
Pinpointing ovulation soon yields other crucial pieces of knowledge; you need to identify it, for example, before you can really know any species’ gestation period (the length of time between conception and birth). In the absence of such knowledge, animal keepers in the past have had only the crudest estimates. “The estimates on the gestation of owl monkeys, for example, range from 150 days to over 300,” says Lasley — not much help if you’re looking out for the newborn to see that it’s okay. Besides gathering data of this sort, Lasley’s researchers are now branching off into a range of related questions: How do you tell exactly when a female is pregnant? What happens to hormone levels right before birth? Can you tell the sex of a ruffed lemur embryo from the mother’s urine?
Lasley himself has begun to imagine taking an additional step, a step he says some of his colleagues may not be ready for. The endocrinologist says that animal managers are conservative to begin with, and they’re most conservative about endangered species; with the most to lose, they want to risk the least. Yet Lasley sees the day coming when zoo people will have to discontinue the hit-or-miss breeding efforts of simply putting the animals together and hoping for the best. He can envision taking all the members of an endangered species which exist in captivity worldwide and working out a global strategy for reproducing them. Lasley knows that techniques like the urinary hormone analysis are so new that they may well require more refinement, but he figures that revolution is in the wind.
In fact, Don Linberg planned to propose such a drastic measure this week at the international conference being held at the zoo. Linberg is the newest addition to the research staff, a biological anthropologist from UCLA, who took a leave of absence from academia to join the pioneering work being done in San Diego. He’s a quiet, graying man and one of the only animal behaviorists in the world working on a zoo research staff. He sees himself fitting into a new. interdisciplinary approach to exotic-animal breeding. He tossed out this revolutionary concept Tuesday: take every single one of the troubled lion-tailed macaques and mount a campaign to correct the species’ reproductive woes. Start by analyzing the chromosomes of every single individual (the ones with gross genetic defects may not be breeding for that reason), then try to check each genetically normal individual that isn’t breeding to see if it’s physiologically fit, and finally address any behavioral problems that remain. “It’s feasible to do this,” says Linberg. “The technique is there. The biggest obstacle may be human reluctance to put the good of the species above individual zoos’ own breeding and display programs.”
In the meantime, Linberg has more than enough puzzles to keep him busy. He’s asked all the San Diego Zoo’s curators to tell him their top three or four breeding problems that seem behaviorally linked. He's already hearing about things like the reptile curator’s headaches with his Komodo dragons (the legendary lizards from one small island in Indonesia, which can grow to be twelve feet long). Linberg says every time the zoo’s male starts to breed with the female, he ends up attacking her. (Can the dragons’ environment be changed to stop the behavior? wonders Linberg at the outset. Should you change their diet? The temperature of their quarters? The humidity?) Certainly the zoo already has its share of success stories that . revolved around purely behavioral adjustments, like the cheetahs which reproduced poorly as long as the males and females were kept together constantly, but which rocketed to spectacular breeding success when keepers began separating them except during the breeding season. (In the wild, cheetah life is strictly sexually segregated.)
Mark Bogart, the zoologist and primate expert, can walk through the research department’s new “primate pad” and show off other cases where environment alone turned out to be the culprit. He stops in front of the clean, airy cages holding the white-lipped tamarins, comical little marmoset relatives which look more like squirrels than primates at first glance. Bogart points out two tiny three-day-old babies clinging to one mother; the six other females all are pregnant and ready to deliver. Yet when six pairs of the tamarins were kept in small storage cages, not a single baby was born. The change in environment made all the difference.
The primate pad where the tamarins are living now just opened last January; the fancy name refers to a large block of various-size cages tucked away on the hill behind the hospital and research buildings. No gawking tourists troop back here. Despite its unprepossessing appearance, the primate pad is like a battleground. The objective is simple; to make more baby animals and use whatever weapons and strategies could possibly contribute to success.
Bogart leads the way to the end of one aisle of animal quarters and unlocks the door of a cage about the size of a typical bedroom. Inside, a family of douc langurs, rare leaf-eating monkeys, greets the zoologist’s arrival with placid stares. The langurs’ story is pitiful — and all too familiar. Native to the jungles of Vietnam, the monkeys fell victim to both the tools of war and the Vietnamese stewpots. No one knows if any remain in their homeland; Bogart thinks the San Diego Zoo got its colony when America had troops in Southeast Asia. In any case, although the delicate-featured langurs thrilled the public with their beauty, the people apparently upset the langurs. On display, the animals reproduced, but many adults and babies died. “We were just barely holding our own,” says Bogart. When the pregnancy of one female, Xuan, ran into trouble, the hormone monitoring techniques developed by Lasley saved the mother’s life. After her estrogen levels plunged precipitously, the zoo veterinary staff did a Caesarean section and removed a dead langur embryo, which would have undoubtedly killed Xuan otherwise. Shortly after that incident, the whole colony was removed from exhibit and finally transferred to the primate pad. There, the Vietnamese monkeys have flourished in the warmer, larger, more private living quarters.
Bogart makes his way to the cage at the other end of the aisle, a container filled with agile, hyperactive spider monkeys. Research on the cellular level revealed a surprise about them; the researchers found that one species of the black spider monkeys, whose members superficially look identical, actually contains three chromosomal variations which can only be detected under the microscope. And it seems that many more baby spider monkeys result if animals with the same chromosome configurations are caged and mated together, something which now has been done.
In the neighboring cage, Bogart introduces more spider monkeys with a different mission. There a mother and her seven-month-old baby are living with a year-old male who spent much of his infancy in the Children’s Zoo. “He’s completely screwed up,” Bogart says. “He thinks he’s a human.” The youngster didn’t relate to other monkeys at all when he first moved out to the primate pad. He sat and rocked a lot and generally acted nervous. Bogart hopes the mother and her baby will help the male to relearn spider monkey ways, essential if he is ever to reproduce normally.
Benirschke, the research director, says that other reproductive centers like the primate pad are scheduled to be built. A bird “brooder” is now under construction, and the primate pad will be expanded when the money becomes available. For the moment, the primates are the only animals living in the special accommodations behind the zoo hospitals, except for a few armadillos and laboratory rats.
One of those rats is quite extraordinary. Named Crystal, it looks absolutely normal now, living with a male with whom it will soon breed. But Crystal began her life in that freezer on the second floor of the old zoo hospital. A scientist named Barbara Durrant cut Crystal out of her mother’s oviduct when the embryo consisted of a mere eight cells. Durrant then painstakingly prepared the embryo chemically, chilled it to the minus-3210 temperature, and left it in the freezer for six weeks. Then she defrosted it, surgically implanted it in another female rat, and sixteen days later. Crystal was born.
Durrant and the San Diego Zoo aren’t interested in increasing rat reproduction. The rat experiment (a procedure done in universities fairly commonly) was practice for some remarkable work Durrant is just beginning. Freezing embryos and implanting them in different host mothers also is commonly done with domestic cattle, but Durrant wants to perfect the technique on exotic animals and to add a science-fiction twist: she hopes to learn whether it’s possible to take the fertilized embryos of one species and then implant them and grow babies in host mothers from a different species.
Durrant is very blond, calm, and pretty; she looks younger than her thirty years. She has a Ph D. in reproductive physiology from North Carolina State University, and she thinks the deciding factor in Benirschke ’s decision to hire her last May was the experience she gained when she worked with commercial cattle embryos one year between graduate schools. The first animals she plans to work with are the ungulates, the family of species which includes not only cows, but also antelope, horses, giraffes, and all other hoofed animals. Both Durrant and Benirschke believe that interspecies transplants of ungulate embryos may well work.
After all, people now commonly implant one breed of cow embryo into a different breed of host mother; frozen Holsteins do well when flown to India and implanted in Brahmins, according to Benirschke. And scientists have bred closely related species to produce hybrids like lion/tiger and gibbon/siamang crosses. Most significantly, a cross-species embryo transplant already succeeded once in 1977. Researchers at Utah State University implanted embryos of mouflons (a rare breed of sheep) into domestic sheep and were able to announce the births of two normal baby mouflons. Sheep and goats resemble each other biologically almost as much as do the domestic sheep and mouflons, so Durant’s first goal is to grow normal baby pigmy and cretin goats in Barbados sheep.
She’s already done the groundwork, starting by chemically synchronizing the reproductive cycles of nine females (three Barbados sheep, three cretin goats, and three pigmy goats) at the Wild Animal Park. Durrant and the park’s veterinarian carefully noted when each of the animals went into heat ten days ago. They should go into heat again and be mated this weekend, and sometime next week Durrant will surgically juggle the embryos around. Lasley’s hormone technicians will monitor the implanted animals' urine to ascertain whether the pregnancies are proceeding. If all goes well, Durrant will have a goat emerging from the Barbados sheep’s womb sometime in early March.
It may not work, of course. First, Durrant’s transplantation techniques could be faulty, and secondly, the differences between growing baby Barbados sheep and baby pigmy and cretin goats may be too considerable for the switch to succeed.
Durrant doesn’t expect to see quick results; she predicts it may take one or several lifetimes of experiments to explore the limits and potential of the transplantation techniques. Also, she sounds certain that the more bizarre and sensational possibilities for cross-species embryo transplants won't prove to be possibilities at all. She says you’ll never see elephants delivering dogs, or monkeys delivering camels, because the foreign embryos would abort instantly. Not only will the size of the finished baby animals have to be roughly comparable, but the placental conditions in the two species will have to be almost the same. Still, Durrant and Benirschke foresee some mind-boggling possibilities: lions bom from tiger mothers, rare antelope bom from more common species, perhaps pigmy chimpanzees birthed from regular chimp females. Why go to all the trouble of implanting embryos in a foreign species when you can-grow them best in females from the animals' own species? Benirschke answers that successful development of the technique would essentially allow more “mass production” of animals belonging to species where there simply are no masses.
“There are sixty okapis (a rare species related to the giraffe] in captivity, and we won’t be getting any more. If we learn this reproductive physiology really well, we could make twenty okapi babies this year. Almost immediately, you’d be through the problem that you faced in the first place. We have a pair of saigas. If you quickly wanted to bring up your population and you knew you could grow ’em in domestic sheep or goats, well, the zoo would do well buying itself five dollars worth of goats and making twenty saigas this year. That’s a very realistic proposition. There is a large number of animals in which there is only a pair or two in the collection and with which the next generation will face brother/sister mating.”
He offers yet another example. “Suppose you have one female oryx [a type of antelope] and one male. You want to have a whole bunch of them. But the male is already very old and he’s likely to die in another two years. Now, say you have a whole bunch of other oryx species that would allow you to make ten fertilized eggs of the original mother [technicians can get female animals to produce multiple eggs by using chemicals; sperm is collected by artificially stimulating the males). You put ’em into ten of the other animals. In one year you’d have ten of the original animals, which would suddenly increase your original population tremendously.”
The oryx example is particularly fitting. In one of the cages down the hill from the hospital, not far from the home of Crystal, the once-frozen rat, lives Rachel, a nine-month-old scimitar horned oryx. Today she’s a shy and beautiful creature who stares apprehensively out from under her straight horns. If Durrani’s work with the sheep and goats succeeds. Rachel will someday become an oryx embryo donor; the researchers already are working to make her as tame as possible to minimize the trauma that always results in interactions between humans and wild animals.
For other reasons, the experience with oryxes is an excellent illustration of the success enlightened exotic-animal breeding can spawn. When, in the early 1960s, the Arabian oryx (another species) almost became extinct in the wild, an international drive resulted in the desperate collection of a special herd from which would have to come the salvation of the species, zoologists concurred. And indeed, breeding of the Arabian animal, particularly at the zoological society’s Wild Animal Park, has succeeded remarkably — so well, in fact, that this year the zoo was able to send eight oryxes back to the wild (to the Shaumari Wildlife Reserve in Jordan).
That concept — of using the fruits of reproductive research to “breed up" the number of endangered species and then return them to the wild — is probably the most glamorous and noble role envisioned for zoos. The zoo would thus shed forever its former incarnation as an exploiter of animals and become more than just animals ’ savior — it would become their mes-siah, helping the oppressed species to reclaim their rightful places on earth.
Furthermore, such “repatriation" has even occurred in a few isolated cases: oryxes in Jordan, tortoises sent from San Diego back to their homeland in the Galapagos Islands; nene geese saved from extinction and released back into their native habitat in Hawaii.
But how realistic is repatriation for most species? Benirschke shrugs. “That’s crystal-balling, and it’s very difficult to do,” he says. “The answer depends very much upon the balance to be struck between the Catholic Church and the people. It depends ultimately on a degree of sophistication and education of the populace to accept the notion that you can’t just proliferate forever. Obviously, you're not going to have animals in all the places where they once lived.” But the doctor contends that it’s not too late yet for many of the world’s wild animals. “You could set aside large parks in Africa and say, ‘This is where the elephants are going to live.’ You could refuse to take any more timber out of Borneo and say, ‘This is where the orangutans are going to live.’ ” Benirschke fights a temptation to be pessimistic about the likelihood of such things happening. He can look backward to the day when American pioneers almost exterminated all the bison. “If you had written a prognosis for the bison then, it would have been pretty grim. [America’s bison population has grown dramatically in the last fifty years.] Today I can only hope that in one hundred years, Africa will become sane. ... . And as the population of various countries increases in education and therefore in recognition that their standard of living is limited by the number of kids they have, their level of sanity increases.”
Then Benirschke shrugs again. “The wild is totally out of our control. The year 2000 is out of my control. I’m going to be dead in ten years.” He knows that zoos can’t really count on being able to liberate animals back into the wilderness; moreover, he doesn’t think it matters. He thinks it’s just as important for science to learn to save the world’s animals even if in the future the only place in the world the wild animals will live is in zoos. He’s made his peace with that possibility. He acknowledges that such a future would imply a fundamental change in the nature of zoos; zoos would no longer be places for humans to view up close their fellow residents of the globe. They would be museums preserving the relics of the past. Benirschke also knows that an animal which would dwell exclusively in zoos would undergo a fundamental change — from a product of nature, subject to the subtle, elegant sculpture of evolution, to a product of man, artificially controlled and maintained.
“No question.” The words come clipped, almost impatient. “There is going to be introduced an element of domestification.” Benirschke suggests.that if the day ever comes when zoo animals can be reintroduced to the wild, an evolution back to wilder states can also occur. But if that day doesn’t come, “as far as I’m concerned, it would be better to have tamer elephants than no elephants at all.”
Benirschke says he can’t convince anyone who doesn’t already believe that. He thinks of the young woman he met recently at the hospital where his son, Rolf, the young Charger football player, had been battling Chron’s disease barely holding onto life. When Benirschke walked out of the elevator to leave at nine o’clock one evening, a young woman stepped up to him and asked if he was heading to the Veteran’s Hospital and if he could give her a ride.
“Why did you pick me?” he asked, startled.
“You look like a doctor,” she answered.
“Well, I am a doctor. Okay, let's go.” In the car, he learned that $he was from Tanzania. She had come to San Diego to visit her brother, an oceanographer at Scripps. He was dying from gastric cancer, and the young woman felt the need to talk.
“I felt very compassionate. My son was dying upstairs. I said, ‘I’m working at the zoo.’ And she said, ‘How awful.’ So we talked about the wildlife.”
Benirschke told her how he had quit human medicine. “I said, ‘I know this must hurt because your brother’s dying from gastric cancer. But we have too many people and we’re killing the wildlife.’” She replied that she didn’t want to see animals in the zoo; after all. she lived with them in the bush.
“She said, ‘Your grandchildren will go to a cage and see animals, but it won’t really be the animals. That’s not the animals as they are out in the trees.’ I said, i agree. That’s not the animals in the trees. But at the same time, this is the only thing I can do.’ ”
Benirschke says he couldn’t come anywhere near persuading her that it would be a good thing to save those pigmy chimpanzees, for example. “There are many people I talk to with whom it is very difficult to reach an understanding. ‘So what if mankind knows no more animals?’ they say. ‘So what if there are no more giraffes? So what? After all, we have no more passenger pigeons. The dodo has gone. The blue whale is on its way out. So we 'll see it in books. ’They say, it’s better than having those animals in cages.’ ”
Benirschke is sitting in the chair behind his large, tidy desk, trying to envision a world in which all the wild animals exist only in books. He smokes a hand-rolled cigarette, and the afternoon light glints off the silver armadillo affixed to his necktie. He thinks about all the human medical science which has relied in the past on comparative biology. “But we could learn to live without that,” he supposes with a sigh. He considers how the disappearance of most of the earth’s animal life would change the balance of nature. “You would require a total knowledge of the ecosystem, which we don't have now,” he asserts — but maybe even that lies in the realm of possibility. “You could probably live with cattle, chickens, dogs, cats, and grass and trees. You probably don’t need any birds; you probably don’t need any flowers. I guess that’s possible,” he judges sadly. “But I think it’s undesirable. I think it would be a very impoverished world. And this is the only thing / can do now to try and avoid it.”