The Complicated Legacy Of A Panda Who Was Really Good At Sex

Karen Wille saw her panda friend for the last time in July 2016. He was in bad shape. He was skinny. His once-sleek black-and-white fur had dulled. Wille, a board member and volunteer with the nonprofit Pandas International, knew better than to expect wildlife-calendar perfection, airbrushed and coiffed. Even the most charismatic of megafauna have off days. Behind the big eyes and rounded frames that signal vulnerability and cuddliness to the human brain, pandas are real, live, 200-pound bears. Bears that can shred your flesh. Bears that roll around in the dirt and turn themselves dingy gray. Bears that grow old and frail.

But it was still hard to see reality catching up to her friend. Wille had been to China to visit this specific bear many times before. This time, though, nobody wanted to talk much about how he was doing. His keepers were more protective than normal. Wille had about five minutes with him — enough time for a pat on the head and a carrot. She was heartbroken, but not surprised, when he died five months later.

His name was Pan Pan. It translates to something like “hope,” an identity that likely meant one thing when he was an abandoned, sick cub on a Chinese mountainside and something very different later in his life.

When he died from cancer on Dec. 28, 2016, the 31-year-old Pan Pan was the world’s panda paterfamilias: the oldest known living male and the panda (male or female) with the most genetic contribution to the species’ captive population. Today, there are 520 pandas living in research centers and zoos, mostly in China. Chinese officials say more than 130 of them are descendants of Pan Pan.

Pan Pan saved his species by being really, really, ridiculously good at sex. Before Pan Pan, experts thought that building up a stable population of captive pandas was going to require extensive use of artificial insemination. Pan Pan not only led the way on reproducing in captivity, he taught us that pandas were perfectly capable of doing it for themselves — and they’re now increasingly allowed to do so. Scientists say giant pandas represent, hands down, the most successful captive animal breeding program humans have ever embarked on, and, partly, we have Pan Pan to thank. He was a big, fluffy stud muffin, and he was beloved. “It sounds kind of weird,” Wille said of their first meeting in 2012. “Most people want to meet rock stars or movie stars. I wanted to meet Pan Pan. He was a legend.”

From the edge of extinction, Pan Pan (and pandas) emerged triumphant. And their success is also ours — proof that maybe humans really can clean up the ecological messes that we make. In September 2016, the International Union for Conservation of Nature declared pandas to no longer be endangered. The animal whose image literally represents the fight against extinction is now merely “vulnerable.” Humans can ride off into the sunset with our heads held high.

At least, that’s one way to tell the story. But just as living bears are messier than their plush, gift-shop counterparts, the reality of conservation science is more complicated and nuanced than a poster or a press conference can convey. Pan Pan’s story is about human triumph — and it’s also about our limitations. Even the most well-intentioned plans have unpredictable consequences. And we can never truly erase a legacy of harm. Instead, we point a species in a new direction, we cross our fingers, and we hope.

Ready for their close-up: Two sets of panda cubs are prepared to meet the public in China. The photo on the right is from 2013; the cubs on the left were born this year. GETTY IMAGES

In 1983, bamboo stalks across south-central China’s Baoxing County all went to seed at the same time, and panda experts panicked. While bamboo forests appear densely packed with plants, those represent the cloned offshoots of a mere handful of individuals, each of which will live to be only about 60 years old. Near the end of its life, the bamboo plant (and its hundreds of thousands of copies) makes one attempt at sexual reproduction. Heavy masses of seeds grow from the stalks, bending them over like wheat ready for harvest. The seeds scatter and the plants — all of them, for miles around — die.

When that happens, it’s bad news for panda bears. Even though pandas have the guts and stomachs of carnivores, their diets are almost exclusively made up of bamboo. After a mass bamboo die-off, it can take 10 to 20 years before the forest is fully re-established. That means years of famine for pandas — years of eating bugs and grass, years of intestinal problems and hunger, years of sickness and death. This cycle is natural, but human activities have made it harder. By the late 20th century, farms, roads and the logging industry had hemmed the bears in, making it difficult for them to simply lumber along to a place where bamboo was still plentiful. Habitat loss, in fact, was the primary issue forcing pandas to the brink of extinction. When the United States formally listed the panda as an endangered species in 1984, the Federal Register noted that the entire panda species — 1,000 individuals — was living on 11,000 square miles of land. Just four years later, China’s Second National Giant Panda Survey would show this estimate to have been incorrect. Instead, those 1,000 pandas had been living on just 5,000 square miles.

To protect the pandas, Chinese officials implemented emergency measures: refugee camps for starving pandas, food drops where workers left piles of cooked pork chops in the forest, a baby lift operation that scooped up young pandas and deposited them in zoos and research centers where nothing could come between them and a regular dinner bell. And this is how Pan Pan came into our world. It’s not clear who found him, but he soon ended up in the home of a man named Li Wuke, who was already caring for another baby panda called An An.

Li Wuke played surrogate father to two pandas, Pan Pan and An An.

This part of Pan Pan’s story isn’t well-documented, and what bits of it have been passed down, largely through Chinese media, make the situation sound like a cross between a shoestring animal rescue operation and the elevator pitch for an animated musical. Li Wuke was an old man who lived in a tiny house in the mountains. He fed the two cubs, scolded them when they were naughty and slept between them at night in one narrow bed.

Pan Pan was a lovable plush mascot in the making — but he was also starting a life as a scientific research subject. Conservation isn’t usually described as an experiment, but in many ways, that’s exactly what it is. The Chinese government had been working hard to keep pandas safe since 1946, when it banned panda export and hunting by foreigners. But in the 1980s, the combination of a very real threat of extinction and advancements in reproductive technology turned attention to captive breeding. A healthy, self-sustaining population of captive pandas could be a safety net — assurance that the species would survive even if humans destroyed its habitat. That population could even be used to repopulate the wild, healing the damage humans caused. But nobody knew exactly how to do all of that.

On April 7, 1986, Pan Pan was given his first entry in the Giant Panda Studbook — a thing that really does exist — as Panda No. 308. The book is the definitive database cataloging the biographical details of every panda that has ever lived in captivity. It describes Pan Pan as a wild male, likely born the previous year and captured in Baoxing. And while the news reports suggest that Pan Pan’s idyllic childhood frolicking around the feet of Li Wuke lasted just one year, his entry in the studbook shows five unaccounted-for years in captivity in Baoxing, a gap that would take him to sexual maturity. On March 4, 1991, he was transferred to the panda breeding center at the Wolong Nature Reserve in Sichuan province. Wherever he was during the intervening years, reaching breeding age meant that Pan Pan, the beloved orphan, was now No. 308, the potential sire.

Pandas are not the only species whose lives are recorded in the staccato of a studbook — name, date, serial number. You can find similar books for elephants, gorillas, golden tamarins — basically any animal whose existence has ever been seriously threatened enough that humans want to make sure that it has lots of babies, and that those babies are genetically different enough from one another that they could keep the species alive without inbreeding. These documents are the checkbooks for living, breathing biological bank accounts. And they help scientists decide how to invest those savings in the form of breeding plans: which animals will mate, when they will mate, and how many babies need to be made each year.

But initially, there weren’t many panda births to record. At the time of Pan Pan’s first entry in the studbook, far more captive pandas had been brought in from the wild than born under human care, a fact that would remain true for another decade. In fact, between 1936 and 1998, only 12 males and 21 females reproduced in captivity at all. And of the captive cubs that were born from 1963 to 1998, 48 percent died within their first month of life. Few baby pandas lived past age 3.

It’s not abnormal to initially struggle to get a wild species to breed in captivity, but pandas proved to be particularly resistant. Some of that has to do with biology. Both males and females live solitary lives in the wild, coming together to breed once a year, during the two or three days when the females are fertile. If this works, and a baby (or two) is born, it will stay with its mother for as long as three years.

This naturally slow process had a reputation for getting even more bogged down behind bars. When Pan Pan arrived at Wolong, the thing captive panda mating pairs were best at producing was awkward moments. Sometimes, males wouldn’t appear interested in sex, as though they’d stumbled into a boudoir when they were looking for the kitchen. Other times, they’d just sort of dry-hump, like teenagers in the back of a Chevy. Worst of all were the times when either the male or female would get aggressive, lashing out violently at their would-be partner.

This is panda reproduction as most of us are probably familiar with it: bumbling, sometimes brutish and massively unproductive. Then came Pan Pan, the Dean Koontz to the other male pandas’ J.D. Salinger. Just six months after Pan Pan arrived at Wolong, his first child was born, a daughter called Bai Yun, who now lives in the San Diego Zoo. That’s remarkably quick work given that a panda gestation period lasts three to five months. Papa was a rolling stone.

By 1999, Pan Pan was the primary male breeding at Wolong, said David Wildt, head of the Smithsonian Conservation Biology Institute’s Center for Species Survival. In 2004, Pan Pan was featured in a research paper that quantified behavioral differences in mating success. The conclusion: He (and a couple of other particularly successful males) were just generally more interested in sex — and male interest in sex was a major factor in whether mating occurred. The paper noted that Pan Pan stood out for his especially long copulation time, upwards of seven minutes on average. “We have seen Pan Pan dragged by females around the entire circumference of the enclosure with no interruption of coitus,” the paper noted.

By 2006, Pan Pan was the parent of more than 30 cubs. No other panda, male or female, even came close. Meanwhile, the number of baby pandas born each year began to skyrocket. In 1991, the year Pan Pan’s first child was born, there were eight new captive panda cubs worldwide, according to the studbook. In the year 2000, 20 were born. Today, it’s not uncommon to get twice that number of panda babies in a year. By early October, the 2017 crop had reached 63. Pandas are now in such good shape as a species that scientists at Wolong have begun a program to return them to the wild. Pan Pan has become known as the “Hero Father.”

This might be the point where Pan Pan’s story starts to sound weirdly familiar, at least to those of you who’ve spent much time reading the Old Testament or the Koran. Lost boy found in the tall grasses? Taken in by a kindly stranger and raised as a prince? He becomes a great leader of his people, but — just as they reach the promised land that he has helped them to find — he dies. The metaphor fits together kind of eerily well. Except for one awkward bit. If Pan Pan is Moses, then we, humanity, are left playing the part of Egypt.

If the details of Pan Pan’s life document humans’ success as conservators, those details also document the complexity of what “success” really means. Again, conservation is an experiment. When we take an animal to the brink of extinction and back, that isn’t the same as returning to a pristine past. There are side effects that can’t be avoided. There are debts that can’t easily be repaid. Saving a species from ourselves is messy — and we aren’t always the heroes of that story.

For instance, the bears have often been framed as their own worst enemies — reluctant to mate, slow to reproduce. Faced with the most primal of animal urges, these particular animals do not feel especially urgent. But that stereotype is built on human error — and the mistakes we made in our early, clumsy attempts at matchmaking.

We wanted pandas to have sex on our terms, as research subjects. We expected them to mate in public, with whatever partners we chose for them, no real chance to get accustomed to each other and little knowledge of how adult pandas negotiate sex. “But … listen here,” said Meghan Martin-Wintle, executive director of the captive-breeding research nonprofit PDXWildlife and a postdoctoral researcher at the San Diego Zoo Global Institute for Conservation Research. “Animals choose partners based on a variety of reasons. As humans, we don’t even understand what those reasons are.”

And, when the pandas predictably rebelled against this experience, humans turned to artificial insemination — a process that amounted to minor outpatient surgery. During artificial insemination, male pandas have to be anesthetized and then stimulated into ejaculating with the help of an electric probe placed in their rectums. Female pandas also have to be sedated during the actual insemination. Some bears went through this process several times during their fertile period every year, said Kati Loeffler, a veterinary adviser to the International Fund for Animal Welfare and former director of animal health at the Chengdu Research Base of Giant Panda Breeding in western China. Loeffler has since become a fierce critic of animal welfare practices within the panda breeding program.

But it wasn’t artificial insemination that led to the panda baby boom. Instead, that success was the result of a slow realization that pandas did better breeding on their own terms, as bears. Today, Wolong and its network of breeding centers favor the natural mating strategies that made Pan Pan famous, said Martin-Wintle and other researchers. There, pandas are given opportunities to mate with multiple partners. Young males get to see other adults mating. When it’s their first time, they’re paired with experienced females. Even when females are both inseminated and allowed to mate naturally, the father usually turns out to be one of the natural mates, said Kathy Traylor-Holzer, senior program officer of the International Union for Conservation of Nature’s Conservation Planning Specialist Group. Meanwhile, the zoos still most dependent on artificial insemination are places that only have two adult pandas who just aren’t that into each other.