Monkeys on the Rock

Author: Ed Cohen


According to legend, if the ravens ever disappear from the Tower of London both the tower and the British kingdom will crumble. And so, at the venerable stone compound in the center of London one of the colorful Yeoman Warders or Beefeaters (familiar to drinkers of the gin brand of the same name) is appointed Ravenmaster. It’s his job to feed and care for a flock of at least six of the traditionally ill-boding black birds so they always feel welcome.

Also, their wings are clipped so they can’t fly away.

About a thousand miles south of London, a parallel superstition holds sway. The future of one of the last vestiges of the British empire, Gibraltar, on Spain’s southern coast, is said to depend on monkeys. And in a sense, maybe it does.

In 1704, not long after British and Dutch forces captured Gibraltar from Spain, a shepherd led 500 Spanish soldiers up a goat path on the sheer, eastern side of the Rock. The sneak attack was foiled, it’s said, when sounds of agitation from the Barbary apes living there alerted the garrison. Thus was born the belief that as long as the "apes"—actually macaque monkeys—live on Gibraltar, Gibraltar shall be British.

The British military fed and managed Gibraltar’s macaques for decades until ceding the job to local authorities in the 1990s. When the macaque population dwindled to seven during World War II, Winston Churchill ordered seven more ferried over from North Africa.

It’s unclear how this sovereignty-monkey linkage works, but there’s no arguing with results. This past year Gibraltar celebrated (and Spain rued) 300 years of continuous British control of the area while the macaques ambled contentedly over the vegetated, western side of the Rock, high above Gibraltar city and harbor. On most days the monkeys can see across the blue Straits of Gibraltar to the northern coast of Africa, where their ancestors likely originated.

Gibraltar’s macaques are a major tourist attraction. According to local officials, more than 700,000 visitors a year pay to drive their own cars or take a tour bus, van or cable car up the Rock, designated a nature preserve since 1990. The descendants of one of the first British colonial governors owns the cable-car concession and one of the largest tour bus operations. Some taxi-van drivers are said to make the equivalent of well over $100,000 a year.

As lucrative as the monkey business has been for Gibraltar, though, it’s unclear how long the present arrangements can last. In the early 1990s, the Gibraltar Ornithological and Natural History Society, a local environmental activist group, took over the job of feeding most of the monkeys from the British military. Soldiers have mostly withdrawn from the colony. In an age of cruise missiles and spy satellites, occupying the high ground at the entrance to the Mediterranean Sea no longer holds much strategic importance.

Tension exists because the nature society’s leaders, who hold advanced degrees in environmental sciences, aren’t satisfied with being merely monkey feeders and rest-stop custodians. They wonder if it’s safe—for man and monkey alike—to have so many people touching and feeding the animals. Plus, there’s the challenge of keeping the macaques up on the Rock instead of down among the homes and trash cans of the 30,000 Gibraltarians who live in the city at the foot of the Rock.

No one had ever methodically studied how Gibraltar’s macaques interact with tourists and the locals until this past summer, when Agustin Fuentes, a primatologist and associate professor of anthropology at Notre Dame, spent a month there with a team of eight research assistants, mostly undergraduate anthro majors. The project was supported by a grant from the Notre Dame Institute for Scholarship in the Liberal Arts.

Fuentes and the students were warmly welcomed by the nature society, which figured the study’s findings would bolster arguments for more money and less interference from the government. But their presence also aroused suspicion. Would these outsiders decide it was too dangerous to have people mingling with monkeys and tell them to build a zoo? That kind of change would likely cripple the tourist trade, which has taken on added importance in the wake of the military’s departure. Fuentes and the nature society assured people that this was only a preliminary study to get a handle on existing conditions.

What they didn’t mention was that results from certain aspects of the investigation could possibly lead to the macaques being sequestered, removed or even exterminated.


Legend has it that Gibraltar’s macaques came from Morocco via a tunnel under the Straits of Gibraltar. More likely they were brought over by the Moors when those North African Muslims conquered the Iberian Peninsula in the eighth century.

According to Fuentes, macaques have been living on the Rock for about 800 years and elsewhere in Europe for even longer. Macaque remains have been found entombed under the lava that buried Pompeii. The Greek physician Galen, looking for a close approximation of human anatomy, peeled back the skin of a close relative, Barbary macaques, to make his pioneering medical drawings. For thousands of years macaques were kept as pets in Europe or used in theatrical productions.

Fuentes, 38, has spent years studying macaques as they live in captivity or around populated areas in Morocco and in Bali in Indonesia. There they have the run of Hindu temples and are allowed to devour food and flowers set out as offerings to the gods. As in Gibraltar, the Hindus’ special treatment represents a kind of debt of gratitude. In the epic Hindu story of Ramayana_, a monkey uses magic powers and his army of monkeys to defeat an evil demon and rescue the wife of a hero. Because of the popularity of the story, macaques and the long-tailed langur monkeys are given food and protection in many parts of India, even when they take up residence in cities and become nuisances.

Fuentes, who co-edited the book Primates Face to Face_, is one of a small number of primatologists who focus on monkeys and humans living in close proximity. He calls the conventional man-versus-nature perspective a “false dichotomy” because people are always reacting to nature and nature is always responding. Plus the buffer zones are disappearing. Every day, human activity encroaches farther and farther into former wilderness areas, gobbling up natural habitat. In recent years suburbanites in the United States have grown accustomed to seeing deer in their backyards. Monkeys aren’t likely to follow, because 90 percent of the world’s primates live in tropical forests. But those are the areas being converted the fastest to human use, chiefly agricultural.

Animals living close to human populations almost inevitably creates tension and conflict, from stolen crops and property damage to increased risk of disease transmission—animal to human and vice versa. Displaced species that fail to adapt or whose presence humans won’t tolerate face bleak prospects. Fuentes writes that 50 percent of all primate species are considered a conservation concern and 20 percent are seen as endangered or critically endangered.

Fuentes had never studied the macaques on Gibraltar before last summer, but he knew all about macaque behavior. Like other primates, including man, macaques are social animals. They live in groups and spend hours on “mutual grooming,” picking through one another’s fur looking for ticks and debris. Macaque infants, who have black fur, sometimes play the role of tranquilizer. When a fight breaks out between males, one male will race off and grab the nearest infant, even tearing it away from its mother. The kidnapper then commences grooming it intently and the other combatant joins in. It seems to make them forget what they were fighting about.

The most obvious difference between apes and monkeys is that monkeys usually have tails and apes don’t. Thus, gorillas, gibbons, chimpanzees and orangutans are all apes. The tailless Barbary macaques are an exception. In their case, the distinction boils down to the ratio of brain size to body size. Macaques, smaller than chimps, have monkey brains.

According to Fuentes, macaques in captivity have been known to live as long as 30 years. In the wild a female will sometimes make it into her early 20s, but males never live past their teens. The oldest macaque on Gibraltar last summer was a 20-plus-year-old female, Elizabeth, named for the British monarch who visited in the 1950s.

The nature society maintains a daily count of the macaque population and names every animal. Eric Shaw, the group’s director of operations, said that in recognition of the Notre Dame research team’s efforts he was going to name a newborn Rockne.

The nature society feeds the monkeys each morning by visiting five tourist sites along the switchback road leading to the summit and setting out a mix of potatoes, sweet potatoes, cabbage, carrots, melons and oranges. In the wild, the macaque diet includes small animals, insects, leaves, seeds, roots and fruit.

Signs everywhere on the Rock forbid others from feeding the monkeys. The animals are already being fed a well-balanced diet, the signs explain; giving them anything else could make them obese and shorten their life span.

The signs also admonish visitors to observe the monkeys from a distance because too much interaction with humans breaks down their family structure. They say not to touch the monkeys because it can make them aggressive and bite. And if they touch you, wash your hands before eating, the signs warn. Don’t carry visible food items because they will try to steal them.

The posted fine for feeding a macaque is 500 British pounds, the equivalent of more than $900.

Since the ban went into effect in the early 1900s, there has been one prosecution.


At one of the tourist stops along the switchback road, a tour van driver is giving a young male macaque a drink. From a can of Coca-Cola.

The driver looks up and sees Tricia David, a Notre Dame senior from Page, Arizona, dutifully recording the event on a form pinched to her clipboard.

“You don’t have to write this down,” he says sheepishly.

But she does. And she did.

It’s Fuentes’s job to crunch the numbers and analyze the data from this study. It’s the students’ responsibility to record essentially all that data, endless details about human-monkey interactions. The students work in pairs, trudging out to the tourist sites once in the morning and rotating to one of the four other sites in the afternoon.

Their first task upon arrival is to inventory the number of people and monkeys present. Then it’s time to record behavior. For each interaction—defined as a monkey or a person doing something and the other reacting—more than a dozen questions must be answered: Who initiated the contact? Into what age groups did the people and monkeys fall? Was food involved? What kind? Was it dropped, handed, held or placed on a surface? Was there a tour guide present?

One student scans the area and records every interaction he or she sees during a 10-minute period. The student will repeat this process three more times over the course of an hour.

The other student selects a single macaque and records every interaction in which the monkey engages during a 15-minute period. The goal is to record three of these so-called “focals” in an hour, following a macaque of a different gender/age group each time.

It isn’t always easy. If one’s focal monkey jumps a wall and disappears into the brush you have start all over with another one.

The second hour the students switch jobs.

At some locations and during certain times of day no monkeys are present, the tourists don’t linger, and time passes slowly. But at two of the five sites—Ape’s Den and Prince Phillip’s Arch—there are almost always monkeys. Mostly they sit on boulders or balance on the road’s cable guardrails, watching the tourists, grooming each other or picking through the fruit and vegetable pieces remaining from the latest drop by the nature society.

At midafternoon a visitor leaning up against a wall near one of the tour stops is surprised and delighted when a large macaque walks by and inadvertently brushes against his back, not unlike a cat rubbing against its owner’s leg.

“It’s amazing how tame they are,” the visitor remarks.

Nothing amazing about it, Fuentes says. “It’s the context of how they’ve been living for hundreds of years. It’s like saying it’s amazing they can climb a tree. They are accustomed to it.”

Maybe too accustomed.

About halfway up the Rock a middle-age woman emerges from a snack bar holding a chocolate-covered ice cream confection called a Magnum. A stranger warns her to be careful because the monkeys love ice cream. Two minutes later she is standing rigid, mouth open, Magnum gone.

The culprit, having snatched it out of her hand, sits in a closed patio area beyond a locked iron gate enjoying the confection unhurriedly and without apparent remorse. Fuentes says he has seen the same animal liberate four Magnums and a frozen lime bar in under seven minutes.

“If they hear something that sounds like a wrapper they perk right up and go toward that sound,” the ponytailed primatologist says.

When not on observation duty students sometimes trade stories of monkey larceny. Meegan Anderson, a senior from Glen Ellyn, Illinois, says she once saw an adult female actually enter the snack bar and run out a short time later carrying a bag of peanut M&Ms in one hand with three more bags tucked under her arm.

Student say they’ve seen the macaques eat peanuts, hard candy, sunflower seeds, tomatoes, graham crackers, corn chips, potato chips, popcorn, bread, dry pasta, croissants, apples and gum. If a tour van’s door is left open, some will climb inside to steal a sandwich.

Such snacking, says Fuentes, poses the same health risks to the macaques as to people: cavities, ulcers, high cholesterol. The no-feeding rule is never enforced because there’s nobody around to enforce it. No wardens are posted at the sites, and the nature society’s two-person food-delivery team has no authority to issue citations.

Katie Hogan, a junior from Wichita, Kansas, says she once had an American tourist come up to her while she was doing observations and point out people who were feeding monkeys. “They said, ‘The sign says right there that there’s a 500-pound fine. Why aren’t you doing anything? Isn’t that your job?’” It wasn’t, of course.

It’s usually not the tourists who feed the macaques—not intentionally, anyway—it’s the tour-van drivers. Here’s what happens: The same group of monkeys hangs out at each location every day, and every day they see the same drivers. Over time the animals learn which drivers offer treats and what tricks they’re expected to do to get them. At one tourist stop in particular—Prince Phillip’s Arch, second from the summit—the animals behave more like circus performers. A driver pulls out a bag of peanuts and gestures to a tourist standing next to him. An attentive male hurries over and jumps up on the tourist’s shoulders for a picture. At a signal the animal hops down and receives its reward. Some macaques let drivers pry open their mouths to show tourists their fangs, which can be up to three inches long.

“They’ll just sit there and let them do it because they know they’re going to get fed afterward,” says Tricia David.

Fuentes says the actions demonstrate how “incredibly mellow” this species of monkey is. But that doesn’t stop him from worrying about the animals becoming aggressive.

Steve Luke, a graduate student from New York who is studying the history and philosophy of science at Notre Dame, remembers a day he was doing observations at the highest tour stop on the Rock, the upper terminus of the cable car. People were walking up the stairs to the viewing platform, he says, “and the monkeys all started making threat faces and moving down the stairs.” The panicked tourists turned tail and raced down the stairs.

Luke isn’t sure what caused the disturbance but says, “Once one of the males gets into a prolonged conflict they all get a little nervous and start jumping on everyone.”

Sometimes aggression has an obvious purpose. At Prince Phillip’s Arch one day, a 2-year-old male jumps on a man’s shoulder, steals his golf hat and hops around on a trellis just out of reach of a tour guide. Someone in the group yells, “Give him a Euro [the European community’s equivalent of a dollar],” which produces laughs but no hat. A few minutes later the macaque surrenders the headgear after extorting a whole banana.

More often the physical contact initiated by the monkeys is playful. For some reason a young male in the group that lives near the souvenir shop likes to pounce on Anne Kwiatt, a senior from Vernon Hills, Illinois. Students are instructed to ignore the behavior and walk away. The monkeys eventually get bored and hop down.

Eric Shaw isn’t as lucky. The nature society director visits the feeding sites so often that the monkeys have come to recognize him—and his car. From experience they know that, unlike the tour group drivers, who will swat at a macaque with a cane or rag to get it off their vehicles, Shaw never retaliates. As a result, the animals jump on his vehicle, bend the antenna over and pry off whatever parts they can. Having stripped the vehicle of all of its body side molding, they’ve now started in on the rubber holding the windshield in place.*








It’s early evening about two weeks into the project. After recording monkey-tourist interactions all day, five of the students are up on the veranda of the research team’s quarters doing calisthenics. Push-ups at the moment.

Typical of any group of Notre Dame students, this one includes plenty of athletes. Katie Hogan and Anne Kwiatt are members of the Notre Dame women’s boxing club. Tricia David is a rower.

The professor and students are staying at a turn-of-the-century British colonial home called Bruce’s Farm, named for a colonel who once lived there. It’s now owned by the nature society. The house perches on the west side of the Rock, hundreds of feet above the city of Gibraltar with a spectacular view of the bay and Spanish coastline. Temperatures remain comfortable day and night with low humidity. The screen-less windows are almost always open because there aren’t any mosquitoes.

The accommodations are hardly elegant, and are even crumbling in places. There’s also not a lot to do at night. The house has a TV but no cable. Gibraltar has only one television station, GBTV. One night the station’s local newscast airs a report on the presence of the Notre Dame research team. The 203-year-old Gibraltar Chronicle later follows suit with a front-page piece.

A steep path leads down the Rock face to the city, but with cable car service ceasing at 5 p.m. daily (earlier if it’s windy), that means a grueling return walk. Mostly Fuentes and the students read, enter data in the computer, check their e-mail or watch one of the few movies on video in the house.

Everyone pitches in on the chores. A schedule posted on the refrigerator names the pairs responsible for cooking and cleaning up each day. These are the same teams who work together in the field. Fuentes organized the twosomes himself based on perceived compatibility. Six of the eight students are women. There are no mixed gender pairs.

Although the weather and scenery suggest otherwise, this is no vacation. The students all had to apply to work on the project, which carries three academic credits, and not everyone was accepted. Several are seriously considering careers in primatology. One, Meegan Anderson, has conducted research at the Brookfield Zoo near Chicago and hopes to publish a research paper.

It’s unusual for undergraduate students to conduct field research like this. Usually professors turn to graduate students, but Notre Dame doesn’t have a graduate program in anthropology. Fuentes tells the students that those interested in continuing to work on the project in the fall could become co-authors on one or more papers published in scientific journals—a dream credential for anyone eyeing graduate school.

Two weeks into their observations, the initial fun of watching the often-comical monkey behavior has lessened, but in its place they’ve acquired a more analytical interest in the animal’s social structure. There’s also the other half of the job—watching the tourists. The students sound alternately bewildered and appalled by the behavior of visitors to the Rock.

Noelle Easterday, a junior from Washington state, recalls a 12-year-old English girl she saw at the cable car terminus. The girl had been feeding one of the monkeys earlier, and when she reached out for the animal it snapped at her.

“She was saying to it ‘We don’t bite. We don’t bite’ and waving her finger in the monkey’s face. And he bit her. Then she says, ‘How dare you, you cheeky little monkey.’ And it bites her again. She starts moving away and screaming, and it bites her little sister.”

Unlike many of the tourists, the students aren’t eager to pose for a photo with a monkey on their shoulders. They know from observations that, in spite of the preoccupation with mutual grooming, macaques don’t practice especially precise hygiene. Anywhere a monkey sits is likely to receive what is referred to around Bruce’s Farm as “transmission of fecal material.” And that can lead to the ingestion of salmonella or campylobacter bacteria, known to cause serious gastrointestinal disorders. Easterday cringes at the memory of overhearing a little girl tell her parent, “I touched the monkey—I’m not going to wash this finger for a week.”

After dinner Fuentes calls the students back to the dining room for a review of data gathered so far. He’s smiling.

“The work you’re doing is very, very good,” he tells them. “I guarantee you there will be some [journal] publications to come out of this.”

As expected, the data point at the taxi-van drivers as facilitators of most of the interaction, especially at Prince Phillip’s Arch. An encouraging sign is that only 19 bites have been observed over the equivalent of nearly 100 hours. (“It’s probably easier to get hit by a bus,” the professor quips.) The source of the largest number of bites, eight, is the gang of rowdy young males at the cable car terminus.

On the minus side, 15 to 20 percent of interactions are resulting in fecal matter being transmitted. “If they could stop taxi drivers from putting monkeys on people’s heads that would reduce occurrences by about 62 percent,” Fuentes speculates. But without wardens at the tour stops, that’s unlikely to happen. Besides, the possibility of someone contracting an intestinal disorder for lack of hand washing is far from the greatest of Fuentes’s worries.

***The next night at Bruce’s Farm, Fuentes and the students welcome John Cortes, general secretary and research director of the nature society, to dinner. Cortes wants to know what the primatologist thinks of the condition of the monkeys.

“This may not be what you want to hear,” the Notre Dame professor begins, “but, to be perfectly honest, I think all these monkeys are in terrific condition.”

The reason Fuentes suspects that’s not what the nature society wants to hear is because Cortes and Shaw perceive plenty of problems. Not with the health of the monkeys, but in managing them. Without wardens, no one is enforcing the no-feeding rule, and there’s no one to provide tourists accurate information on the animals. Without running water at most of the tour stops, it’s impossible to keep the sites clean. Also, the present feeding method—dumping fruit and vegetables in a pile on the ground—is promoting friction within the macaque groups over who gets to pick first. Shaw would like to see the food more widely dispersed.

Changing those conditions requires more money, which the nature society plans to lobby for when its current contract with the British government comes up for renewal.

“If we would come up with recommendations,” Cortes says, “they would listen to us.”

The nature society also wants greater control. In the past, the tourism ministry, not the nature society, has determined the optimum macaque population for the Rock. In 2003, on a minister’s order, the local vet had 27 macaques euthanized without informing Shaw or Cortes. The population had grown beyond what the ministry considered to be the optimum population: 180 (six groups of 30). Shaw, still angry about the incident, argues that the 180 figure is arbitrary, not based on any scientific evidence.

A spokesman for the government says the cull was necessary because the population had become unmanageably large. Macaques were invading homes and other buildings, including hotel rooms. The animals did more than $50,000 worth of damage to the water system at one hotel, he said.

Cortes acknowledges that at least one group of macaques frequently wanders into town to pick through the rubbish and be fed by people. “Unfortunately, they never unlearn that.”

The ministry spokesman says new contraceptive methods promise to keep the population under control without euthanasia. Also, responsibility for the macaque population has transferred from the tourism ministry to the ministry responsible for the environment.

Shaw insists that the Rock could support 600 macaques if the tree canopy were cut back to allow in more sunlight. This, he says, would encourage the monkeys to forage for more of their own food instead of relying on humans. (Fuentes estimates Gibraltar’s macaques get 10 to 20 percent of their food from foraging.) But grooming the Rock that way also would take more money.

As part of his study Fuentes interviewed scores of Gibraltarians about their attitudes toward the macaques. Many older people, he says, see the animals as pests and want to get rid of them. But the more common sentiment goes back to the notion that Gibraltar might somehow cease being British if the macaques disappeared. GBTV reporter James Neish says the apes are seen as part of the character of Gibraltar, and residents “have a—passion is not the word, but they feel they should be looked after.”

Cortes thinks the number of visitors to the nature preserve should be limited, and both he and Shaw appear to favor changing how monkey and tourists interact. In 1998 the nature society shipped 24 of the macaques to Germany to live in a huge outdoor enclosure. The space allows people to walk through the monkeys’ habitat and see them, but there’s no tossing peanuts or posing with monkeys on one’s head. One unforeseen problem was snow. After the first snowfall, the monkeys, who had never seen snow, didn’t know they could dig through it and their food would be underneath.

If an enclosure like the one in Germany were constructed on the Rock it would solve the problem of monkeys wandering into town and reduce or eliminate potentially unhealthy feeding and physical contact. The question is whether the politically well-connected tourist industry would endorse such a change. That doesn’t seem likely. Shaw says the nature society already requires “political consent” just to tell the tour drivers at Prince Phillip’s Arch that the circus-animal-like behavior they’re promoting endangers the macaques.

Which brings attention back to Fuentes’s study and whether any real danger exists in the way monkeys and people interact on Gibraltar. The answer appears to be: potentially. First there’s the danger to the monkeys, whom Fuentes says can contract airborne diseases like measles and tuberculosis from humans.

“All you need is a kid from Eastern Europe with measles coming through here, and it would run through this population.” He adds immediately, “Then again, it might not happen for 50 years—you don’t know.”

More ominous from a public health standpoint is the possibility of macaques infecting tourists. As part of the Notre Dame study, Fuentes had the macaques tested for the herpes B virus, which macaques are known to carry. Unlike genital or oral herpes in humans, which causes skin sores, herpes B can produce a devastating, even fatal infection of the central nervous system—in people. Macaque carriers don’t suffer any obvious symptoms.

Fuentes says there have been 56 cases recorded of herpes B being transmitted to humans from monkeys in laboratories or zoos. In the past the response has been to destroy the animals to minimize health risks. Wild macaques typically carry the virus also, but, oddly, no transmission to humans has ever been recorded involving wild macaques.

Given the seriousness of possible infection and the volume of interactions with tourists on Gibraltar, what would happen to Gibraltar’s macaques if they were found to be carriers of herpes B?

“Then we would have a problem,” Fuentes says.


After Fuentes and the students complete their month of observations, the primatologist receives back his lab results. It’s good news for the monkeys. Unlike their wild brethren in Asia, the Barbary macaques of Gibraltar do not carry herpes B or many other common macaque pathogens.

In his preliminary report, Fuentes notes that other potential hazards do exist for tourists, including skin- and fur-born parasites like lice and fecal/urine contamination. He recommends running water be made available where the monkeys are present and that visitors be warned more forcefully to wash their hands and any body parts that come in contact with the animals.

One of the more interesting findings from the interaction data is that fewer than half of the macaques on Gibraltar interact with humans on a regular basis. The monkeys seem to be deciding for themselves whether they want to steal ice cream bars, perform tricks or pose for photos. Apparently the majority would rather stay away or just sit and watch.

Ed Cohen is an associate editor of this magazine. He also took the picture, shown above.