Even though the protagonist is a ten-pound bird, this true account has all the trappings of a classic love story. Grape-kun (Little Purple Boy), a Humboldt penguin named for his diminutive size and identifying purple armband, was born in 1996 in a small zoo in Tokyo. When the Tobu Zoo, north of Tokyo, completed its own penguin enclosure in 2006, Grape-kun and his long-term partner Midori-chan (Little Green Girl) were among the couples chosen for relocation. The move took the penguin pair an hour north to Miyashiro, a small city of about 33,000 people, and into a standard rocky enclosure with a pool and a growing flock of birds, now numbering 32.

Miyashiro is located at about the same latitude as San Jose, California. The closer to the equator penguins live, the more likely they are to practice long-term monogamy. In warmer climates, the breeding season runs longer, which makes a penguin’s “mission to procreate less pressurized, so they can spend more time seeking out last year’s successful partner,” as zoologist Lucy Cooke writes in her 2018 book The Truth About Animals: Stoned Sloths, Lovelorn Hippos, and Other Tales from the Wild Side of Wildlife. Galápagos penguins, who live on the equator, are the most faithful of all; 93 percent of pairs reunite every season. Humboldts, a penguin species native to the South American coast, are also known for their fidelity.

In 2010, when he was 14 years old, Grape-kun developed a medical issue with his leg and was removed from the penguin enclosure for surgery and hospitalization. During his six-month absence, Midori-chan began to mate with a much younger male penguin, Denka (the name is a Japanese honorific meaning “Your Highness”). Zoo employees were shocked. “Among penguins, when they become wife and husband, they usually will live together and be the wife and husband for their entire lives,” says Eri Nemoto, one of the penguin caretakers at the Tobu Zoo. But when Grape-kun returned after his treatment, he and Midori-chan never mated again. According to his keepers, Grape-kun showed no interest in any of the other females in the enclosure, and they showed no interest in him. But he was middle aged and also eating well, so the zoo staff wasn’t too worried about him. Penguin life spans in the wild average 20 years; in zoos, they can live up to age 30.

Penguins have long been a popular staple in zoos around the world because they’re small, relatively easy to transport, cheap to house, and dynamic. Due to climate change, habit loss, and industrial fishing habits (in which penguins get caught in nets or drown), 10 of the globe’s 18 penguin species, including the Humboldt, are endangered or under threat.

Underwater, they look like tuxedoed torpedoes; above ground, they waddle with the instability of humans learning to walk. Nearly 100 picture books feature penguins, like the 1938 classic Mr. Popper’s Penguins, and the ‘90s series Pingu, a Swiss-British stop-motion clay animated series, became an international hit. The 2005 documentary March of the Penguins is the second highest grossing documentary in North America, with a global box office total of $127.4 million. Its success led to a flurry of penguin-driven animated movies over the following decade, including 2006’s Happy Feet, 2007’s Surf’s Up, their sequels in 2011 and 2017, respectively, plus 2014’s Penguins of Madagascar—in which a group of diabolical penguins upend the bird’s cartoon stereotype as a lovable tuxedoed gentleman.

“We both judge these animals by rules for human behavior and at the same time look to them as role models,” writes Marlene Zuk in her 2002 book Sexual Selections: What We Can and Can't Learn About Sex from Animals. This was evident in Christian fundamentalists’ love of March of the Penguins—in 2005, conservative film critic Michael Medved called it “the motion picture that most passionately affirms traditional norms like monogamy, sacrifice, and child-rearing.”


Some members of the gay community hold up penguins as symbols as well, and not just to affirm that same-sex relationships are natural, since same-sex penguin partnerships are widespread and well-documented, but also to suggest that same-sex families are also natural. The most famous “gay” penguin parents are Roy and Silo of the Central Park Zoo. In 1998, they courted one another, pair-bonded, and built a nest together. They were later observed trying to incubate a rock and attempting to steal another penguin couple’s egg. (Eventually, in a practice that has since become common at zoos around the world, keepers gave them an abandoned egg to incubate.) With its coverage of same-sex love, adoption, and gay marriage, the resulting 2005 picture book, And Tango Makes Three, remained the most frequently challenged book by religious conservatives for nearly five years straight. (The penguins’ six-year relationship also ended in 2005, a few years after they reared a chick together, when Silo left Roy for a female penguin named Scrappy.)

Underwater, they look like tuxedoed torpedoes; above ground, they waddle with the instability of humans learning to walk.

But penguins themselves provide the counterpoint to their use as symbols of traditional Christian monogamy or family-oriented gay couples, as zoologist Cooke points out in The Truth About Animals. Cooke details the experience of pioneering penguin researcher Dr. George Murray Levick, who spent 12 weeks in 1911 on Antarctica’s Cape Adare, which has the largest Adélie penguin colony in the world. Levick was so unsettled by the sexual practices he witnessed, the resulting article, “Sexual Habits of the Adélie Penguin,” included the bolded header “Not for publication.” Levick described what he called “bands of hooligan cocks” whose “constant acts of depravity” included group sex, necrophilia, and pedophilia. “There seems to be no crime too low for these penguins,” the zoologist concluded by the end of his trip. (The rampant sexual behavior among cold-climate penguins has been attributed to a very short breeding season that puts immense pressure on the birds to copulate; young inexperienced males might mistake dead females for females in a copulation pose.)

The late Dr. Levick would probably turn over in his grave to hear what was recently discovered about female Adélies. They are, according to New Zealand biologist Dr. Lloyd Spencer Davis, one of the few animal species besides humans and chimps that appear to engage in prostitution. After 1,700 hours of note-taking on a remote island 800 miles from the South Pole, Dr. Davis and Dr. Fiona Hunter published a study about partnered female Adélies trading sex with unpartnered male Adélies and, immediately after the sex act, taking rocks (a valuable resource for nest building) from the males’ nests in order to reinforce their own. “Cases of transactional sex are surprisingly rare in the animal kingdom—and hotly contested,” Cooke wrote, though female Adélies might be “a little more human than we may have expected, though perhaps not in a way the Christian right would be keen to discuss in Sunday school.”

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The Tobu Zoo has over 1,200 animals, including brown bears, flamingos, a white rhinoceros, African elephants, and a rare species of white tiger. In response to mounting pressure from animal-rights activists and shifting public perception, many zoos around the world have refocused on conservation and education instead of entertainment. The Tobu Zoo is not one of those zoos; in addition to keeping its animals in relatively small enclosures, the zoo has attractions like roller coasters and a wave pool. In April 2017, as part of a promotion for the manga artist Mine Yoshizaki’s anime show Kemono Friends, the zoo placed 50 cardboard cutouts of the show’s animal-turned-teenage-girl characters in their corresponding enclosures. Though most animals in the zoo ignored the cutouts, if they noticed them at all, Grape-kun became transfixed by the cutout that appeared in his enclosure one day, that of Hululu, an anthropomorphic penguin-girl.

Yoshizaki had clearly done his homework when creating Hululu—the two-foot-tall cutout was both penguin-shaped and penguin-colored. The white headband of her headphones (which look like a pair of Beats knockoffs) mirrors the white band that runs behind Humboldts’ eyes. The front of her oversized white hoodie has the pale dark flecks of the birds’ chests and the stripe of black that winds its way up the penguins’ sides and arcs across their torsos. The back of her hoodie and its arms, which conveniently cover her hands, give Hululu the appearance of having wings.

Hululu’s appearance in the penguin enclosure followed the show’s January to March 2017 run, but April also happens to be one of the two peak times for Humboldt mating. As visitors quickly noticed, Grape-kun appeared besotted with Hululu. He would stand beneath her for hours on end, staring up at her; at some points, he tried to climb up to the rocky outcropping on which she’d been placed. His keepers decided to move Grape-kun away from the cutout at certain times of the day so that he would focus on eating. Atsushi Yamada, who cares for the penguins at the Tobu Zoo, says that penguins “base their activities on their favorite place” and that “even if we kept him away from the panel, he always returned and stared at Hululu.”

Grape-kun’s story went viral in late April, after a Twitter user with less than a thousand followers shared two photos of him staring at Hululu. A few days later, the Tobu Zoo got involved, tweeting photos of Grape-kun and Hululu and offering affirmative commentary about the former’s interest in the latter; soon enough, the story was picked up by both local and international news outlets. Zoo staffers said that while tending the penguins, they noticed that the same people would return day after day. Entranced visitors watched Grape-kun stare at the cardboard cutout. “They were gazing at the penguin as if they were looking into themselves for long hours,” Yamada says.

When the advertising campaign for Kemono Friends ended in June, the cardboard cutout of Hululu stayed. Removing Hululu from the enclosure didn’t seem to arrest Grape-kun’s ardor for her. When a typhoon threatened to blow away the cutout last September, keepers removed it from the penguin enclosure. A widely shared photograph shows Grape-kun looking longingly as the cardboard figure is carried away, tucked under a zookeeper’s arm. He waited in the same spot for her to return; thankfully, the wind died down enough so that she could be replaced the following day. The financial benefits to the zoo were clear: visits increased 20-fold and most visitors went straight for the penguin enclosure. To capitalize on the attention, the zoo was making plans for a festival celebrating the romance.

Zoo staffers said that while tending the penguins, they noticed that the same people would return day after day. Entranced visitors watched Grape-kun stare at the cardboard cutout.

In online communities, the term “waifu” refers to a female character, often from manga or anime, to whom one is attracted. Fans of Grape-kun began to refer to Hululu as his waifu, and Midori-chan as his former wife. Over the course of my interview with caretaker Atsushi Yamada, he uses the term “falling in love” to describe what happened with Grape-kun and the Hululu cutout. I ask if this is what he really believes. He hedges at first. “In my professional opinion, I cannot definitely say that he was in love, but, personally, I can see that he was attached to the cardboard panel and I think he was in love,” he responds.

If Grape-kun could fall in love, presumably he’d also be capable of experiencing heartbreak, or at least stress and emotional strain from continually trying to get the attention of what he considered an ideal mate but was nothing more than a nonresponsive piece of cardboard. But if his keepers were worried about his emotional health, they didn’t let on. (During our interview, they did mention concerns over the toll the campaign might have had on his physical health; Yamada explained that they feared all that standing in one spot might damage Grape-kun’s previously injured leg.)

The media discourse surrounding Grape-kun’s obsession was overwhelmingly positive, but on forums, anime fans debated whether what was unfolding at the Tobu Zoo was “adorable on so many levels” or a case of animal cruelty. Still, Grape-kun’s story did not spur op-eds on the role of the zoo in the 21st century. According to the media, the story of Grape-kun and Hululu was really about love.

The appearance of what’s taken for love and loneliness in nonhuman animals has always driven human imagination and scientific inquest, but whether it says more about us or them is debatable. When it comes to animal love, the most iconic figure is likely the lobster, popularized by a 1996 episode of Friends in which, during the course of a conversation about Ross and Rachel’s romantic prospects, Phoebe explains that “it’s a known fact that lobsters fall in love and mate for life … You can actually see old lobster couples walking around their tank, you know, holding claws.” (Ross later tells Rachel, “You’re my lobster.”) The truth is more complicated: even though lobsters mate with “a poignant gentleness that is almost human,” as one lobster researcher explained, they do not mate for life.

Thankfully, there are a number of other animals on which to foist our romantic sentiments, like bird pairs of great tits, who “stay together no matter what,” according to Scientific American. Mostly, animal love and loneliness are the domains of slide shows, GIFs, or video clips, where just a snippet of information about one individual or pair captivates millions. Such was the case with Nigel, “the world’s loneliest seabird,” who captured international attention in August 2016 after photographs and videos depicted the creature trying to woo concrete decoys painted to look real on a small island off the coast of New Zealand. “Get your existential sadness clicks elsewhere,” on writer tweeted at news outlets breathlessly covering Nigel; another Twitter user called the seabird’s hopeless devotion to a concrete female “beautiful yet tragic.”

The type of anthropomorphism that happens frequently in the public sphere has long been a subject of scientific debate and philosophical inquiry. When René Descartes suggested animals are more like wind-up toys, capable of independent-seeming movement, but unable to reason or feel pain, naturalist John Ray fired back. In 1691, he wrote, “[If] beasts were automata or machines, they could have no sense, or perception of pleasure, or pain … which is contrary to the doleful significations they make when beaten, or tormented.”

The influence of behaviorism on the scientific community in the 20th century meant accepting a view closer to Descartes’s than Ray’s, even though similar ideas had been championed by Charles Darwin just decades earlier. “In the analysis of animal behavior we have been strongly conditioned to avoid anthropomorphism as a cardinal sin against scientific standards,” Dr. Donald Griffin, a professor of animal behavior at Rockefeller University, wrote in a 1977 issue of BioScience, before conceding that “the task of confidently designating which human attributes cannot possibly exist in other species has become more and more challenging.”

“In my professional opinion, I cannot definitely say that he was in love, but, personally, I can see that he was attached to the cardboard panel and I think he was in love.”

A year later, the physiologist started a field within the discipline of animal behavior studies that he called cognitive ethology: the study of animal minds. Cognitive ethology emphasizes both theoretical and methodological changes in studying animals—suggesting that scientists can no longer ignore consciousness in animals and encouraging the study of animals in their natural habitats. The titles of Griffin’s books trace his shift in thinking: Question of Animal Awareness (1976) was followed by Animal Thinking (1984) and then Animal Minds (1992), which gained the subtitle Beyond Cognition to Consciousness in 2001. When he died in 2003, the New York Times cited numerous scientists who suggested Griffin was “the only reason that animal thinking was given consideration at all.”

Griffin and his colleagues faced harsh criticism from the start. It was a time when “ethologists who wished to use metaphors drawn from human experience to describe or explain behavior often issued gratuitous disclaimers, not unlike the ‘but I am not a communist’ apologia of 1950s labor organizers,” wrote Dr. Peter H. Klopfer, professor emeritus of Biology at Duke University, in a 2005 analysis of ethology in the 20th century.

Today’s skeptics suggest that cognitive ethology is too closely affiliated with the animal-rights movement, excessively reliant on anecdote, and too willing to ascribe emotions that aren’t scientifically documentable. Cognitive ethologists, in turn, point out that lab scientists have intentionally distanced themselves from the animals they study in order to carry out grim experiments. When cognitive ethology began, practitioners referred to animals by name, while lab scientists tended to use numbers.

Dr. Marc Bekoff, professor emeritus of ecology and evolutionary biology at the University of Colorado, Boulder, is exactly the kind of scientist that critics of cognitive ethology like to point to. “My folks always say, ‘When you were young, you would always be minding animals’ and what that meant was that I was attributing minds to them, but also minding them because I was so appalled by how they were treated,” he tells me. After college Bekoff became a vegetarian, then a vegan; and in the 2000s, he cofounded Ethologists for the Ethical Treatment of Animals with Jane Goodall, an organization that works to develop and encourage ethical standards in ethological research and encourage policy changes.

“I get really pissed off when people say, ‘Oh, well we don't really know [if animals can feel emotions],’” he says. “I've done my research. Some people say, ‘Well, behavior itself isn't convincing.’ I think it is. But when you combine the behavior with what we're learning from neurobiology and neuroimaging studies, I mean it, it's insane [to doubt that animals are conscious and capable of emotion].” The ability to see what goes on in the brains of animals, instead of just studying their behavior, has yielded major discoveries, even among the smallest of creatures. Studies on the humble fruit fly, for example, have shown that they enter a neural state likely analogous to fear when confronted with visual threats. (A researcher studying neural pathways relating to desires, rewards, and memory in fruit flies recently said that it’s “not totally ridiculous to suggest” that better understandings of these patterns of circuitry in flies could eventually contribute to the development of treatments for humans with addiction issues.)

My request to a prominent animal-behavior society for a connection to an expert in animal emotions was met with this response: “[It’s] not necessarily [that] we don’t believe they exist but rather [that animal emotions] would be very hard to document.” When I ask about the idea that positive animal emotions might be harder to document than negative ones, which some other scientists suggest, Dr. Bekoff is frustrated. “To me, the argument is very simple,” he explains. “If animals can feel pain and suffer and grief, then there's no doubt that they can feel love and attachment and friendship.”

“There is no room for complacency,” biologist John S. Kennedy cautioned in his 1992 book The New Anthropomorphism. “If the study of animal behavior is to mature as a science, the process of liberation from the delusions of anthropomorphism must go on.” Kennedy rejected the idea of evolutionary continuity between species in the development of consciousness. Clearly influenced by Descartes, Kennedy suggested that even a machine can be made to look conscious when, of course, it isn’t and that behaviors in nonhuman animals, like nest building and imitation, have mechanical underpinnings. He likened anthropomorphism to a “disease” that needed curing if the study of animal behavior was to carry on with scientific rigor. The book was Kennedy’s first and last, published in the year of his 80th birthday. After his death, his daughter revealed that he often asked his cat Tigger what she was thinking. (“So in the final analysis, in regard to his cat, John was not totally able to practice what he preached,” Ronald J. Prokopy wrote in a postmortem tribute.)

But Kennedy, in his criticism of anthropomorphism, did suggest that it is an inborn trait in humans to anthropomorphize. In that, he seems have been right. One recent review of scientific literature on the subject, published in the renowned journal Animal Behaviour in 2015, concluded that attributing mental states to animals may well be an “unavoidable consequence of the functional organization of the human brain.” A 2011 analysis found that babies pay more attention to animals than any other type of visual stimuli in their environment, suggesting that we may have an inborn affinity for other animals.

“If animals can feel pain and suffer and grief, then there's no doubt that they can feel love and attachment and friendship.”

As for the animals themselves, numerous studies suggest that the closer they are to humans (behaviorally and morphologically), the more likely we are to map our experiences onto theirs. (That means mammals over all other animals, and vertebrates over invertebrates.) This produces a domino effect for animals lucky enough to be easily projected upon: we attribute higher moral status to them and are more likely to donate money to their conservation.

NGOs tend to focus on what are called “flagship” species, those that are popular and beloved, using them for campaigns, mascots, and logos, in addition to conservation attention. The World Wildlife Fund uses a panda as its mascot and logo; in the past decade, thanks to habitat protection and captive breeding programs, wild panda populations have increased 17 percent. But highlighting the cutest and most popular animals also raises funds for the less appealing. The World Wildlife Fund spends $246 million annually on conservation (most of which comes from charitable donations); among their ten priority animal clusters are big names (gorillas, bears, big cats) but also sturgeons and vultures.

The influence of proximity extends beyond popular opinion and charitable giving. “A similar tendency holds even for governmental decision making: species that are phylogenetically closer to humans or are similar in appearance to humans receive a higher share of conservation funds and policy attention,” wrote the authors of the Animal Behaviour review. This happens both between animal types and within subcategories; among vertebrates, those that happen to look physically similar to human infants—with big eyes and oversized heads—receive more conservation focus than those who don’t.

Most people who insist their dogs have personalities or that Grape-kun was in love have never heard of the Cambridge Declaration on Consciousness. On July 7, 2012, a group of prominent animal researchers released an “unprecedented document” according to the New York Times, and not just for its content, but also because of its format: “scientists, as a rule, don’t issue declarations,” the Times noted. The Declaration’s authors wrote that “while comparative research on this topic is naturally hampered by the inability of nonhuman animals, and often humans, to clearly and readily communicate about their internal states,” there were still a number of findings that could be “stated unequivocally,” chief among them that a large percentage of animals, including mammals, birds, and even some invertebrates like octopuses possess the ability for consciousness and, most likely, self-awareness and emotion.

One recent afternoon, I called up Dr. Alexandra Rosati to find out a bit more about how this type of research on animal consciousness impacts our understanding of the ways we’re different from other animals. Rosati is the director of the Cognitive Evolution Group at University of Michigan, where she also works as an assistant professor of psychology and anthropology, studying the evolutionary origins of the human mind. I asked her for the current working definition of what makes humans human.

She laughed, called it a challenging question, and then responded. “It used to be that you could clearly define humans as the tool-using species and that's completely not a good definition anymore,” she says. “There was a major proposal at the end of the 20th century that seemed really like it held water that other primates don't have what's called theory of mind, which would mean that they can’t think about other minds and can only think about observable behaviors in others.” Rosati suggests that primates do have theory of mind, an idea that’s controversial, but gaining increasing scientific support through studies that show primates behaving in ways that seem to indicate awareness of the perceptions, beliefs, or ideas of others. She notes that similar findings have occurred with language and culture, two more domains once believed to be solely human.

In the debates over whether animals are being anthropomorphized, humans have rendered themselves gods of the animal kingdom, doling out consciousness, intelligence, and emotion to creatures that appear most like us.

“I don’t think it’s going to be the case that we find like one key difference, totally absent in all other animals,” she says. “It’s more of a quantitative difference between us and other animals.” In 1871 Charles Darwin wrote that “the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind,” an idea that lost favor for much of the 20th century. “Not very long ago, you couldn’t even talk about these things with colleagues,” the late Jaak Panksepp, a pioneer of affective neuroscience who studied emotion in rats, told the New York Times Magazine in 2014. When Bekoff, who’d been speaking openly about animal emotions and consciousness for years, got a press release about the Cambridge Declaration (“Scientists Declare: Nonhuman Animals Are Conscious” the subject line read), he thought it was a headline from the Onion. Upon realizing it wasn’t satire, he felt vindicated and delighted.

When we attribute mental capacities to animals, we both empathize with them more and show greater support for their rights, according to a number of studies. Similarly, when we consider an animal’s emotional experiences, we become more concerned for them. The intensity of Grape-kun’s devotion to Hululu makes it easy to assume that before her arrival he was lonely, maybe even desperate for social contact, and upon her arrival, swiftly fell in love. As it turns out, those feelings of loneliness and love weren’t just in Grape-kun, but also in us. A 2008 research article in Psychological Science reported that lonely people find nonhuman agents like dogs or iPhones or God to be more humanlike than non-lonely people. “This reasoning points to the possibility that when an entity is anthropomorphized, it becomes a source of social connection,” three authors wrote in a 2013 Journal of Experimental Social Psychology report on the effects of anthropomorphizing nature and animals.

The term anthropomorphize was not originally applied to animals but to conceptions of God, and to define God in human terms was seen as sacrilege. In the debates over whether animals are being anthropomorphized, humans have rendered themselves gods of the animal kingdom, doling out consciousness, intelligence, and emotion to creatures that appear most like us. But 21st-century findings have upended that notion, forcing us to reckon with the fact that many animals once thought to be mindless automatons are sentient beings. Maybe the real problem with anthropomorphizing animals isn’t that it falsely attributes human experience to other animals, but that, in doing so, we limit their experiences to the confines of our own lives.

In May 2017, just one month after Hululu was introduced into the penguin enclosure, actress Ikuko Chikuta went to see for herself what was really going on between Grape-kun and the cardboard cutout. Chikuta is the actress who voices the character of Hululu on Kemono Friends, and she was deeply moved by their meeting. Even though she’d seen the numerous photos online, the 26-year-old was still surprised by what she saw in the penguin enclosure. “He didn’t move, he was just gazing at her,” she tells me. “Other penguins were going to eat their meal and Grape-kun did not go.” Chikuta was a bit worried for Grape-kun; Hululu, of course, wouldn’t ever respond to him. But still, she left the zoo with what she called “a sense of wonder” and a feeling of closeness to the bird.

Later that month, Chikuta returned to meet Grape-kun face-to-face, and a Japanese talk show filmed their interaction. She is shown feeding fish to the penguins in front of a crowd but when the camera pans out, Grape-kun stands alone, near Hululu, seemingly disinterested in food. Eventually, the two pose for photos. In one of the resulting photographs, Chikuta holds Grape-kun out in front of her. She’s smiling, he’s twisting away from her, unaware that the woman holding him is, in some sense, Hululu herself. She tells me, “I felt almost like his mother and that he’d brought a lover home.”

Last October, Grape-kun’s keepers noticed a drop in the penguin’s weight. They removed him from the enclosure for medical attention, and to keep him happy, brought Hululu along too. Two days later, the zoo announced that Grape-kun had died at the age of 21—a long life for a Humboldt penguin in captivity—and the tweet announcing his death garnered nearly 127,000 retweets. The zoo said his cause of death was unknown. There was an outpouring of grief, including purple flowers laid at the zoo, letters from local schoolchildren, and fan drawings that circulated online. According to his handlers, Grape-kun and Hululu were together until the very end.

Japanese translation and interpretation provided by Mika Tanegashima.