How to Tame a Fox (and Build a Dog)

by Lee Alan Dugatkin

  The foxes at the house also became more protective of Lyudmila and “their” usual people. One day in July 1977, a researcher and a student from the Institute who had never been to the house stopped by to see the foxes. When they entered the house, Pushinka became furious. The only other time Lyudmila had seen her react so aggressively was the night she had chased after the guard and barked at the woman. Lyudmila had never heard her bark in quite that way again, and she wasn’t barking now either, but she was growling very aggressively, which was a behavior the elite foxes didn’t normally exhibit. Pushinka was clearly differentiating people who were associated with the house from strangers. There seemed no doubt that Pushinka was learning some of her new behaviors.

  THE DEBATE ABOUT THE RELATIVE IMPORTANCE of innate versus learned behavior, which Belyaev had soaked up at the Edinburgh conference in 1971, had not died down in the years since. Lyudmila’s findings with Pushinka offered powerful evidence for the view that a hard line one way or the other on this issue was simply misguided.

  Particularly vehement controversy had erupted over the work of primatologist Jane Goodall, who made astonishing observations of chimpanzees at the Gombe Reserve in Tanzania, on the east coast of Africa. She had started observing them in 1960, at the suggestion of paleontologist Louis Leakey. Leakey and his wife, Mary, had been making remarkable finds of the fossilized skeletons of proto-human ancestors at Tanzania’s Olduvai Gorge, and Louis thought observing the behavior of primates might help to illuminate how those early human ancestors had lived. Goodall’s reports on the nature of chimp society, and how human-like so much of their behavior was, had captivated the public from early on. In some animal behavior circles, some people strenuously objected to many of Goodall’s assertions about the implications of the behavior she had seen. In her book In the Shadow of Man, she wrote captivating descriptions of the close-knit nature of chimp communities: “I saw one female, newly arrived in a group, hurry up to a big male and hold her hand toward him. Almost regally he reached out, clasped her hand in his, drew it toward him, and kissed it with his lips. I saw two adult males embrace each other in greeting.” The young chimps seemed to revel in their daily camaraderie with “wild games through the treetops, chasing around after each other or jumping again and again, one after the other, from a branch to a springy bough below.”4

  Goodall argued that individuals in groups displayed distinctive personalities, and that while mother-child bonds were the most powerful, strong social ties bound not only members of immediate families, but also larger groupings. Chimps seemed to genuinely care about members of their groups. They shared food, and came to the aid of one another when necessary. To her horror, as she continued to observe the chimps in the mid-1970s, she also observed acts of extreme violence, watching more dominant females kill the offspring of other females in a group, as well as group killings by males, which sometimes even ended in them eating the group member they had killed. That animals would kill one of their own in such a strategic manner had also been considered a uniquely human characteristic. It wasn’t, and that was disappointing to Goodall. “When I first started at Gombe,” she wrote many years later, “I thought the chimps were nicer than we are. But time has revealed that they are not. They can be just as awful.”5

  The seemingly human-like behavior of the chimps suggested to Goodall, and many others, that they had higher order thinking abilities, and more human-like emotions, than primatologists had thought. This was fueling new speculation about the nature of animal minds and how sophisticated some animal thinking, and learning, might be. The work also stirred up new ideas about how much more like our primate ancestors we humans might still be. But some ethologists thought Goodall had gone way too far in her conjectures about the chimp mind. They argued that she was anthropomorphizing, projecting human qualities onto the chimps that they didn’t really have. The fact that she had given names to the chimps, like Greybeard, Goliath, and Humphrey, fueled that fire. But especially strong objection was made about her assertion that chimps were so smart they’d learned to become tool makers. Among her earliest observations, she watched chimps strip the bark from slender twigs and then insert them into termite mounds, pulling them out and slurping up a teeming feast. This seemed to her clear evidence of tool use, which no primate but humans had been thought capable of. Some animal cognition experts were unconvinced; they argued that this behavior couldn’t be taken as evidence of anything like human-style problem solving or reasoning.

  Certainly the learning Lyudmila was seeing in the foxes was nothing on the order of that required for tool use, but Dmitri and Lyudmila considered it important in understanding the process of domestication. They were not specialists in animal cognition or emotion, and they weren’t equipped to perform a study of the foxes’ cognitive abilities, or any analysis of whether they felt anything like human happiness and affection when they were wagging their tails, whimpering, licking hands, or rolling over onto their backs. Gaining definitive insight into animal emotion, they believed, might not be possible, which many experts today argue is still true concerning animal emotion.

  But they had no doubt that living with Lyudmila had accentuated the domesticated behavior of Pushinka and her family. They had all learned to be quite a bit more dog-like. Lyudmila had also observed what she thought were signs that Pushinka was exhibiting a rudimentary form of reasoning ability.

  A particularly memorable instance of this was a sly trick that Lyudmila witnessed Pushinka play on a crow—a trick that fooled Lyudmila as well. One day when Lyudmila was on her way back to the house from spending some time with the foxes at the farm, she saw Pushinka lying perfectly still in the grass in the back yard of the house. She looked like she wasn’t breathing. Terrified, Lyudmila rushed over to her, but Pushinka remained totally still, and even with Lyudmila so close, showed no signs at all of breathing. Lyudmila turned to rush to get the vet. Just as she turned, she noticed a crow fly down onto the yard near Pushinka. In an instant, Pushinka sprang to life and grabbed the crow. How, Lyudmila thought to herself, could such clever planning be explained if Pushinka wasn’t capable of some sort of simple rational thought? Her performance suggested that she understood the crow would see her as being dead, and seemed to involve a basic understanding also that some crows like to feed on dead animals. If so, her trap had been set brilliantly.

  Perhaps the most astonishing instance of what seemed to be a kind of inference by one of the foxes happened when Marina, an assistant who had come to help with the work at the new house (not Marina, Lyudmila’s daughter), sat down in the house to smoke a cigarette, as she did every day. One of the foxes in the house, which she had nicknamed Jacquelin, was especially taken by Marina and the feelings were mutual. When Marina sat down for her smoke that day, the ashtray that was usually on the table where she was sitting wasn’t there. She asked the others in the house whether they knew where it was, and everyone started to search for it. Suddenly they heard some noise from behind a cupboard in the room, and out came Jacquelin pushing forward the lost ashtray. They were all amazed.

  Perhaps it was sheer coincidence, and Jacquelin had simply stumbled on the ashtray and was playing with it as if it were a toy. But it certainly seemed that she had understood what Marina was looking for. Perhaps she had made the connection by having observed Marina smoking so many times. Lyudmila had no way of getting inside Jacquelin’s mind, so she couldn’t pursue this hunch. In the coming years, a researcher who did have expertise in animal cognition would learn about the foxes and travel to Akademgorodok to conduct a fascinating study that demonstrated just how strong their ability to make inferences from observing people is.

  WHAT LYUDMILA AND DMITRI WERE EQUIPPED TO investigate further was the other ways that innate traits and learning might be affecting their tame foxes. They were constantly availing themselves of the latest techniques for research, and during the time Lyudmila was living at Pushinka’s house, she and Dmitri decided to see whether they could delve even deeper into wh
at degree the behaviors they were seeing in the tame foxes were genetically based.

  Even as they tried to hold all conditions constant for the foxes, there were subtle, almost imperceptible differences that could creep into an experiment. For instance, what if the tamest mothers treated their pups differently than the aggressive moms treated their pups? Maybe pups learned something about how to be tame or aggressive toward humans from the way their moms treated them?

  There was only one way to confirm for certain that the behavioral differences they were seeing between the tame and aggressive foxes were due to genetic differences. Dmitri and Lyudmila would have to try what is known as “cross-fostering.” They’d have to take developing embryos from tame mothers and transplant them into the wombs of aggressive females. Then they would let the aggressive foster mothers give birth and raise those pups. If the pups turned out tame themselves, despite having aggressive foster moms, then Lyudmila and Dmitri would know that tameness was fundamentally genetic and not learned. And, for completeness, they would also do the same experiment with the pups of aggressive mothers transplanted into tame mothers to see if they got parallel results.

  In principle, cross-fostering was straightforward; researchers had used the procedure to examine the role of nature versus nurture for many years. But in practice it was easier said than done, it was technically difficult to pull off, and it had worked much better with some species than others. No one had ever tried to transplant fox embryos. Then again, no one had tried lots of things they had done, and so Lyudmila decided she would have to learn this delicate procedure on her own. She read all she could on transplant experiments that had been done in other species, and she conferred with the veterinarians they had on staff. Lives were at stake, so she took her time, learning everything she could.

  She would be transplanting tiny, delicate embryos—on the order of eight days old—from the womb of one female into the womb of another pregnant female. Some of the embryos from tame mothers would be transplanted into the wombs of aggressive mothers, and some of those of aggressive mothers would be transplanted into the wombs of tame mothers. When the pups were born seven weeks later, she would closely observe their behavior to see if the pups of tame mothers became aggressive and if the pups of aggressive mothers became tame. But how in heaven’s name was she going to know which pups in a litter were the genetic offspring of the mother and which pups were the ones she had transplanted? Without that information, the experiment was futile. She realized that the foxes had their own unique color coding system. Coat color is a genetic trait, so if she carefully selected the males and females so that the coat coloring of their offspring would be predictable, and the pups of the aggressive mothers would have different colors from those of the tame mothers, she’d be able to tell which pups were the genetic offspring of a female, and which had been transplanted.

  Lyudmila led the transplant surgeries with her faithful assistant Tamara by her side. Each surgery involved two females, one tame and one aggressive, each about a week into pregnancy. After lightly anesthetizing the foxes, Lyudmila made a tiny surgical incision in each female’s abdomen and located the uterus, with its right and left “horn,” each of which had embryos implanted in it. She then removed the embryos from one uterine horn and left the embryos in the other. Then she repeated the procedure with the second female. She transplanted the embryos that had been removed from one mother into the other in a drop of nutritional liquid that was placed into the tip of a pipette. “The embryos,” Lyudmila recalls with the pride of a job well done, “stayed outside the uterus [at room temperature from 64 to 68 degrees Fahrenheit] for no more than 5–6 minutes.” The females were then moved to a postoperative room and given time to recover.

  Everyone at the Institute anxiously awaited the results. Even with the surgeries having gone so well, the transplanted embryos might not survive. Their wait paid off. It was the caretakers who were the first to discover the births of the first litters, which was often the case with new developments with the foxes. They sent word right away to the Institute. “It was like a miracle,” Lyudmila recorded. “All the workers gathered around the cages for a party with wine.”

  Lyudmila and Tamara began recording the pups’ behavior as soon as they left their nests and began interacting with humans. One day Lyudmila watched as an aggressive female was parading around with her genetic and foster pups. “It was fascinating,” Lyudmila recalls, “. . . the aggressive mother had both tame and aggressive offspring. Her foster tame offspring were barely walking but they were already rushing to the cage doors, if there was a human standing by, and wagging their tails.” And Lyudmila wasn’t the only one fascinated. The mother foxes were as well. “The aggressive mothers were punishing tame pups for such improper behavior,” Lyudmila recalls. “They growled at them and grabbed their neck, throwing them back in the nest.” The genetic offspring of the aggressive mothers did not show curiosity about people. They, like their mothers, disliked humans. “The aggressive pups on the other hand retained their dignity,” Lyudmila remembers. “They growled aggressively, same as their mothers, and ran to their nests.” This pattern was repeated over and over. Pups behaved like their genetic mothers, not their foster mothers. There was no longer any doubt—basic tameness and aggression towards humans were, in part, genetic traits.

  The house experiment with Pushinka had shown that tame foxes had also learned some of their behavior. Living with humans had taught the foxes additional ways of behaving, some of which they shared with their domesticated dog cousins. Genes surely played an important role, but the tame foxes were not simple genetic automatons; they learned to identify individual people and became particularly bonded to them, and even defended them, owing to the process of living with them. That these learned behaviors were so dog-like provided the tantalizing suggestion that wolves in the process of transforming into dogs might also have learned these behaviors by living with people. Dmitri and Lyudmila had produced some of the best evidence that an animal’s genetic lineage and the circumstances of its life combined in generating its behavior, and had done so in a highly innovative way.

  BACK WHEN DMITRI HAD FIRST EXPLAINED HIS plan for domesticating foxes to Lyudmila, she had thought about the moving words of the fox character in Antoine de Saint-Exupéry’s classic story, The Little Prince. “You are forever responsible for what you tame,” the fox tells the prince. She felt that responsibility intensely, as did Dmitri and her assistants, and to some extent all those at the Institute. This, in part, was why they had hired some night watchmen to keep an eye on the farm and its precious inhabitants. With that sense of responsibility had also come love. Living in the house with Pushinka and her pups, Lyudmila and her assistants had truly come to love their companions, every bit as much as dog and cat owners love their pets. There was no point, Lyudmila knew in her heart, in denying that. The powerful love they were feeling was also important in illuminating how the bond between people and animals had become so strong.

  Inevitably, that love also carries with it great sorrow and loss.

  On the morning of October 28, 1977, as Lyudmila and Tamara approached the experimental house, they didn’t see the foxes peering out the windows, and as they got near the front door, they didn’t hear them yammering with excitement. This was very odd; the foxes always greeted them. They anxiously opened the door. No foxes came running to jump all over them. As they walked into the house, they realized it was empty. Then they noticed blood marks all over the room, on the floors and the walls. Horrified, they realized that some thugs had broken into the house in the night and killed the foxes for their furs.

  Lyudmila and Tamara were in shock. After a few moments of stunned silence, they burst out crying. Then, suddenly, they heard some whimpering, and to their great joy, little Proshka, the most timid of Pushinka’s grandsons, came scampering into the room. “When Proshka heard our voices,” Lyudmila remembers, “he came out of his hiding and didn’t leave our side.” The quietest of all the foxes,
the one who was such a loner, had been clever and lucky enough to survive.

  Proshka required special attention for some time in order to return to his normal self, and then continued living happily in the experimental house. More foxes were brought to the house, and before long, they had pups, including one who was named Pushinka II. And the foxes continued to live in the house for several more years, with no further incidents. Lyudmila, though, spent less time there. She had other work and it was simply too painful.

  How the murders could have happened remains a mystery to this day. The house was surrounded by a high fence, and the doors of the house, which were locked, had not been tampered with. The two night watchmen who patrolled the fox farm reported nothing unusual. The police were called in. They were tight-lipped about their investigation—this was the Soviet Union in 1977—but they talked with Lyudmila and Dmitri and they questioned the workers. No one thought they were involved, but they might have seen or heard something. They hadn’t. The murderers, apparently, had come and gone quickly in the dead of night.

  “Almost 40 years have passed,” Lyudmila says today, “[but] I am still horrified.” “One of the reasons for this tragedy,” Lyudmila says, “is that our foxes trusted people, they didn’t know that besides people who love and pet them, there are some people that can shoot them.”

  She was grateful that others took on increasing responsibility for continuing the house experiment. Finding it so painful to spend time at the house, she moved on to launching a new set of illuminating studies with her very special foxes.