Inside Animal Minds: The New Science of Animal Intelligence (5 page)

Like fly-fishing, termite fishing is a meditative, deceptively nuanced activity. I tried it a few times and could not even find an active hole. My probe never sinks farther than an inch or so; the chimps regularly bury theirs a foot or more. They can find active holes by smell, inserting a probe and then sniffing the end of it for
the smell of soldier termite pheromone.

Fongoli chimps eat termites year-round, not just in the dry season, when other foods are scarce. Termites make up, at bare minimum, 6 percent of the Fongoli chimps’ diet. We know this because most evenings at six o’clock, research assistant Sally Macdonald sits down with a set of sieves and buckets, and one or two ziplock bags of the chimp feces that the researchers bring back. She scans the fruit seeds, estimates the percentage of fiber from leaves and shoots, and takes note of bones and termite pincers. “Science in all its glamour,” deadpans Macdonald, whose mother sends ziplock bags but does not know their fate.

A quick glimpse into the bucket reveals that saba fruit is the chimps’ mainstay this time of year, an adult averaging 30 to 40 a day. The Fongoli record for saba seeds in a single fecal sample (499, compared with an average of 75) probably belongs to a male named Mamadou—which may explain why Mamadou is, quoting Pruetz, “especially gassy.”

Pruetz’s Ph.D. student Stephanie Bogart says part of the reason chimps fish for termites is that the insects are an exceptionally calorific food. A 3.5-ounce serving of termites has 613 calories, compared with chicken’s 166. But 3.5 ounces of soldier termites is hundreds of insects, fished piecemeal from a mound. It’s like eating cake one crumb at a time. The chimps must really like them.

Sissy gets up from her spot at the termite mound to select a new tool. She breaks off a length of vine, inspects it. Satisfied, she sticks it in her mouth and carries it back to the mound like a seamstress holding pins between her lips. Pruetz and others argue that female chimps are not only more skilled than males at crafting and using tools, but are also more diligent. Craig Stanford agrees that it might well have been our female ancestors who first steered the culture toward tool use. Early tools for foraging, he imagines, gave way to tools for scavenging meat from carcasses killed and
abandoned by large carnivores. These tools in turn may have paved the way to using implements for killing prey, which makes Pruetz’s observations of chimps sharpening sticks and using them to whack bush babies all the more arresting: Fongoli’s females seem to have skipped ahead to the killing tools. Barbecue tongs cannot be all that far behind.

Pruetz and I are sitting along a forested ravine where the chimps rest during the day’s hottest hours. The vegetation is thicker here. We watch a slender green vine snake move through the grass. Birds are calling over our heads. One says
cheerio;
one actually says
tweet
. A third says
whoop whoop whoop whoop whoop
, like Curly of the Three Stooges. (When I ask what that one is, Pruetz replies, not at all sarcastically: “a bird.” She is a woman of singular interests.)

Pruetz directs my gaze to a tangle of saba vines. Where I see a dark mass, she is able to distinguish six animals. The woman has chimp vision. (It’s a condition that lingers long after she gets back to Iowa. “I get home and I’m looking for chimps on campus.”) The animals can be so well hidden and so quiet that even Pruetz has trouble finding them. She sometimes locates them by smell—“chimp” being a potent variant of B.O. “Yesterday I thought I smelled chimp,” Pruetz says, “but it was me.”

The scene in the vines is one of drowsy, familial contentment. Yopogon is grooming Mamadou. Siberut is leaning against a tree trunk, rubbing his two big toes together, as he often does. A pair of youngsters swing on vines, flashing in and out of an angled shaft of sun. One uses a foot to push off from a tree trunk, spinning himself around. The other swings from vine to vine, Tarzan-style. They are almost painfully cute.

A chimp called Mike lies on his back in a hammock of branches, legs bent, one ankle crossed atop the opposite knee. One arm is behind his head, the other is crooked at the elbow, the hand hanging slack from the wrist, in the manner of a cowboy slouched against
a fence. We stare at each other for a full ten seconds. Partly because his pose is so familiarly human and partly because of the way he holds my gaze, I find myself feeling a connection with Mike.

I confess this to Pruetz, who admits to similar feelings. She cares about the Fongoli chimps as one cares about family. She sends excited emails when a baby is born and worries when the elderly and nearly blind Ross disappears for more than a week. But she does not reveal this side of herself at conferences. There, it’s all lingo and statistics, pairwise affinity indexes, and “blended whimper pouts.” “Especially with male chimp researchers,” she says.

One of the first things primatology students are taught is to avoid anthropomorphism. Because chimps look and act so much like us, it is easy to misread their actions and expressions, to project humanness where it may not belong. For example, I catch Siberut looking toward the sky in what I take to be a contemplative manner, as though pondering life’s higher meaning. What he’s actually pondering is life’s higher saba fruits. Pruetz points some out in the branches above Siberut.

Yet it is impossible to spend any time with chimpanzees and not be struck by how similar they are to us.

I’ve been keeping a list of things I have seen or read or heard Pruetz say that drive home this point in unexpected ways. I had not known that chimpanzee yawns are contagious—both among each other and to humans. I had known that chimps laugh, but I did not know that they get upset if someone laughs at them. I knew that captive chimps spit, but I hadn’t known that they, like us, seem to consider spitting the most extreme expression of disgust—one reserved, interestingly, for humans. I knew that a captive ape might care for a kitten if you gave one to it, but had not heard of a wild chimpanzee taking one in, as Tia did with a genet kitten. The list goes on. Chimps get up to get snacks in the middle of the night. They lie on their backs and do “the airplane” with their children.
They kiss. Shake hands. Pick their scabs before they’re ready.

The taboo on anthropomorphizing seems odd, given that the closeness—evolutionary, genetic, and behavioral—between chimpanzees and humans is the very reason we study chimps so obsessively. Some thousand-plus studies have been published on chimpanzees. As a colleague of Pruetz’s once said to her, “A chimp takes a crap in the forest, and someone publishes a paper about it.” (No exaggeration. One paper has a section on chimpanzees’ use of “leaf napkins”: “This hygienic technology is directed to their bodily fluids (blood, semen, feces, urine, snot) … Their use ranges from delicate dabbing to vigorous wiping.”

As for the chimps, they are not nearly as intrigued by the ape-human connection. While we’ve been observing them, they have largely ignored us, occasionally shooting a glance over one shoulder as they move through the brush. There is no fear in this glance, but neither is there curiosity or any sort of social overture. It is a glance that says simply,
Them again
.

Even Mike. He just turned away from my gaze and pointedly, or so it seemed, rolled over to turn his back on me. In hindsight, I would have to say that the reason Mike had been looking at me was that I happened to be in his line of vision.

The chimps begin making their nests, breaking off leafy branches and dragging them into the treetops. Pruetz will wait until all are bedded down before turning to head back. We sit and listen to their “nest grunts”—soft, breathy calls that seem to express nothing more than the deep contentment one feels at the end of a day, in a comfortable bed.

Primatologist Jill Pruetz holding a “spear” fashioned and used by a Fongoli chimpanzee. To make the weapon, the chimps sharpen a stick with their teeth and use it to hunt nocturnal bush babies, small primates that sleep by day in tree hollows
.

(Frans Lanting/National Geographic Stock)

Kanzi, a bonobo at the Great Ape Trust in Des Moines, Iowa, proudly holds a photographic display of one successful linguistic task. When asked to make a toy dog bite a toy snake, Kanzi correctly placed the dog’s mouth on the snake. When asked to make the snake bite the dog, he correctly reversed their positions
.

(Michael Nichols/National Geographic Stock)

Previously, humans had been thought to be the only species capable of making and using tools. In 1960, Jane Goodall first observed chimpanzees “termite fishing,” using straws, sticks, and vines to extract termites from termite mounds. As her project supporter Dr. Louis Leakey noted in a telegram, the discovery urged the scientific world to “… redefine tool, redefine man, or accept chimpanzees as humans.”

(Frans Lanting/National Geographic Stock)

No ant is in charge in an ant colony. Not the queen, not the soldiers, not the workers. Instead, the colony functions as thousands of individuals informing one another of their surrounding conditions, a principle that humans have begun applying as potential solutions to complex business models
.

(jokerpro/Shutterstock)

A queen bee surrounded by drones and workers. Despite her role as the only bee to always remain in the hive, it is not the queen who decides where their next home will be, but the colony as a whole. Scouting parties try to convince the majority of their fellow scouts by dancing to indicate the most suitable location
.

(JSseng/Shutterstock)

Five swarm-bots communicate with one another during a test run
.
Equipped with sonar, cameras, and wireless Internet, the highly maneuverable robots were developed for such purposes as highly intelligent first-response units during house fires, military campaigns, or natural disasters
.

(Mark Thiessen/National Geographic Stock)

Porcupine caribou migrate annually from Canada’s Yukon Territory to their traditional calving grounds in Alaska’s Arctic National Wildlife Refuge. Herd instincts evolved over centuries have allowed the species to safely travel one of the longest migration routes of any land mammal, even under the threat of predators like wolves
.

(Alaska Stock LLC/National Geographic Stock)