Kill Decision

CHAPTER 5

It was war, then. She had modeled this behavior and detected the cues-but even so, the swiftness of the assault caught her off-guard. Perhaps the stigmergic propagation rate needed to be tweaked.

Professor Linda McKinney stared intently at a procession of salmon-colored, dark-eyed weaver ants, coursing like blood cells along branching pathways. They scurried against a craquelure background of mango bark on highways only they could see, surging into combat against black ants many times their size-swarming over their enemy. The video image revealed the carnage in ultrahigh resolution. The dead were piling up.

Weaver ants- Oecophylla longinoda. Along with mankind they were one of the few extirpator species on earth-meaning they deliberately sought out and destroyed rival organisms (including their own species) to maintain absolute control of their territory.

McKinney zoomed the camera in on a growing knot of weavers, watching as dozens of workers swarmed a much larger, black ant-a Dorylus major, the warrior caste of the driver army ant (which the locals called siafu). The monstrous black ant had one of the weavers in its mandibles, but following a timeless script, the much smaller and faster weavers grabbed hold of their enemy, first immobilizing the massive intruder-and then tearing its legs off. They dropped it among the dead and moved on to their next victim.

Defeating a siafu army ant colony in battle was no mean feat. Here in Africa, even humans steered clear of siafu, which occasionally swarmed in wave fronts twenty million strong into huts and farms. Anything that could not escape their grasp would die. There were authenticated accounts of siafu killing humans who’d passed out drunk, unattended infants, and goats or cows that were tied in place. First suffocated by thousands of ants crawling into their mouth and lungs, the strangled victims would have their flesh removed in hours, leaving only bones behind. There was no stopping the swarm. You just had to get out of the way. And yet, as fearsome as they were, even siafu army ants fled from the weavers.

Weavers were so aggressive that McKinney would hear them in their multitudes, drumming their legs against tree leaves in alarm, sounding like raindrops as she walked through the mango orchards. Gathering their troops. Collectively, they dominated the treetops of Africa-while their close cousins Oecophylla smaragdina dominated the trees of Asia and Australia. What made them even more fascinating to McKinney was that their reign had already lasted more than a hundred million years. Human civilization was barely a blip on their radar screen.

Weaver society was so durable, so adaptable, that these ants had survived ice ages, extinction-level events-like the asteroid impact that doomed the dinosaurs at the end of the Cretaceous period, sixty-six million years ago. In fact, more than merely surviving, the weavers had thrived. In terms of biomass, they now rivaled that of humanity itself. In numbers they were counted in trillions. They were one of the most successful and enduring species on the face of the planet. That was one of the reasons she had spent her adult life studying them. There was an ancient knowledge of sustainability here on a scale humans could only aspire to. And they were fascinating in so many other ways.

McKinney had originally been drawn to myrmecology because of social insects’ unique evolutionary strategy; where most organisms had a single body, Hymenoptera-the order of social insects that included wasps, bees, and ants-were in effect a single organism consisting of millions of separate bodies. The physician Lewis Thomas once described ants as “a brain with a million legs.” It was like being able to send your hand to go get things while you were off doing something else. The great myrmecologist E. O. Wilson proposed that ants were a “superorganism”-an organism that transcended the limitations of a single body to enact a collective will. And that will had an intelligence superior to that of the individual ants themselves. Precisely how this occurred was still unknown, and it was a mystery that McKinney had dedicated her career to unraveling.

Studying the screen, she keyed observations into her laptop and spoke via speakerphone to a graduate student several miles away. “Mike, check the lens on camera nine. There’s an occlusion that’s confusing the tracking software.”

“Got it. Rich, can you move the lift closer?”

Another voice came in over the line. “There in a sec.”

“Thanks.”

McKinney zoomed the image out, displaying dozens of thumbnail video insets on the panoramic HD monitor that, when tiled together, outlined an entire mango tree as a three-dimensional model. She rotated the model as though it were a video game-the difference being that the tree was real and the images real-time. The tree stood on the verdant hillsides near the Marikitanda Research Station, where McKinney ran her field lab. The mango tree’s entire surface was being recorded in real time from dozens of separate digital video cameras placed on scaffolding around it. Software was stitching the imagery together into a single live 3-D image wrapped around the tree. Just one nest out of this colony’s domain of a dozen trees, covering nearly eight hundred square meters of ground with nearly a half million ants in all. It had taken years of research and grant applications for her to get this system up and running-and to obtain such up-close and complete imagery of an entire weaver nest in real time. Of the superorganism in motion. And all to test whether her software model of weaver society was accurate. And, in turn, whether it could form the basis of a general model of Hymenoptera intelligence. That, in turn, might reveal secrets as to the very nature of intelligence itself.

McKinney turned on the tracking overlay and now saw glowing red dots hovering above individual weaver ants. She wanted to confirm that the computer vision software was accurately identifying individual weavers, and correctly distinguishing them from their much larger and darker siafu enemies. The enemy ants were denoted with blue dots by the tracking software. It seemed to be doing a fair job of telling the ants apart. McKinney would use the red dots from the data set to analyze weaver swarming attack. The idea was to capture the geometry of weaver movements, recording their collective action for analysis against her Myrmidon computer model. It would be interesting to see how her behavioral algorithms held up.

She smiled. Either way, this kicked ass. She was finally getting the raw data she needed to refine her model. To understand the processing power of insect societies. How intelligence could emerge from relatively unintelligent agents and amass into a collective mind.

With only a quarter million neurons in an individual weaver ant’s brain, a single ant “knew” very little-especially compared to the one hundred billion neurons in an average human brain. And yet, multiplied by a half million ants, the number of neurons in a colony began to approximate the raw, collective processing power of the human brain.

An ant colony exhibited nothing like a human’s sophistication, of course, but there definitely was a specialized intelligence. One that could plan and deliberately act. She’d seen that with other ant species like Atta laevigata, whose gigantic colonies excavated in Brazil extended twenty feet belowground with populations in the millions. These were cities able to regulate oxygen flow and temperature, able to farm fungi, dispose of waste.

But McKinney had especially seen evidence of collective intelligence in the nation-state-like domain of the weavers, where they maintained not one but dozens of hand-woven leaf nests in strategic locations throughout their territory and kept “livestock” in the form of mealy bugs (Cataenococcus hispidus). Outlying weaver nests were “barracks,” garrisoned to fight any intruders on the borders of their territory. If an enemy appeared, workers would summon reinforcements from these castles, and within minutes even intruders a thousand times the size of a single weaver would be surrounded, immobilized, torn apart, then ingested. But more intriguing still was the way weavers waged all-out preemptive wars of extermination against members of their own species. This was a behavior that on earth was exhibited only by the most complex societies of humans and of ants.

Was the collective processing of individual ant brains a primordial, measurable manifestation of a singularity-a collective mind that comes into being whenever information processing achieves critical mass? These and other questions fascinated McKinney-and with the Myrmidon computer model she was on her way to finding some answers.

There was a knock on her lab door.

“Busy. What is it?”

The door opened, and she could hear the sounds of daily activity in the research station outside. A familiar man’s voice spoke behind her. “Hey, I know this is none of my concern, but weren’t you going to take Adwele climbing up E-39?”

McKinney froze at her keyboard. “Oh, God…” She checked her watch.

“Relax. You said one o’clock, and it’s five till.”

McKinney swiveled in her office chair to face a handsome young entomologist in a stained bowling shirt standing in the doorway. “Jesus, I completely lost track of time.” She got up and started grabbing rope bags, packs, helmets, and other climbing gear from nearby metal shelving.

“Don’t mention it.”

She cast a glance his way. “Sorry, Haloren. Thanks for the heads-up.”

“I didn’t do it for you. I did it for the kid.” He gestured to the computer monitors. “See, ’cause I know how engrossed you can get with your vicious little friends. I’m the same way with dung beetles.”

She laughed. “No, you’re not.”

“If you’re suggesting I wouldn’t have chosen my line of study if I’d known I was going to be picking larvae out of monkey shit all day, you’d be wrong. It’s fucking fascinating. Come over to my cabin some night and I’ll show you.”

“Yeah, I’ll take a pass, thanks.” McKinney knew that most of the women researchers found Haloren’s sarcasm and self-deprecating humor charming. He was a few years younger than she, in his late twenties, and handsome in a rakish way, but also cocky and too self-amused. He mocked everything and, most infuriatingly, was usually right about things that didn’t rise to her notice.

“Who’s your friend?”

McKinney followed Haloren’s pointed finger to the open window next to her workstation. Sitting there on the branch of a colorful bougainvillaea was a large black raven, staring calmly back at them. “I didn’t even notice him.”

“Check it out, he’s tagged.”

McKinney could see a leg band and tiny transponder glittering in the sun. “Someone with funding.”

“The few. The lucky few.” Haloren leaned against her desk. “You know, the Arabs say ravens are the harbinger of omens.”

“Save it for your grad students.” McKinney leaned in to the speakerphone on her desk. “Guys, I’ll be back in a few hours. I had an appointment I forgot. Keep the video running and work out any glitches as best you can in the meantime.”

There was a chuckle on the other end. “No problem, Professor.”

Haloren gave her a look. “Those guys were listening the whole time?”

McKinney shrugged and hung up. She then leaned out to grab the window handle and took one last look at the oddly calm-looking raven, only a few feet away. She’d never thought of ravens as being this big. It was easily the size of a hawk, with a powerful, thick beak that looked like it could crush walnuts. Deep black, penetrating eyes, studying her. It had a tiny, wirelike feather hovering over its head, like a black filament rooted somewhere in the feathers of its neck.

It cocked its head at her with an eerie, deliberate focus.

She took a close look at the transponder on its leg and could see a grid of tiny metallic dots. McKinney looked back up at the raven, who was still watching her. “Hi, there. Where are you from?”

The bird cocked its head again, and then let out a perfect imitation of a chain saw.

McKinney laughed and looked to Haloren in surprise. “I didn’t know ravens could do sound effects.”

“Yeah, they’re great at mimicry. My thesis advisor kept a raven. Pain in the ass. Regularly trashed his office, and it hated my guts.” Haloren waved his hands. “Shoo! Shoo!”

“So maybe it’s the sound of loggers he’s imitating?”

“Probably.”

She turned back to face the raven, but it had taken off, leaving a wagging branch behind. “Why’d you scare him away?” She shut and locked the window.

Haloren held the office door open for her, but pointedly didn’t offer to help lug the forty pounds of climbing gear she was hauling. “After you…”

McKinney marched through the door. “Lock it.”

“Got it. Got it.”

In a few moments they were walking fast on the bustling dirt road running down the center of the research station. Local Maasai people in both Western clothes and traditional kanga nodded to them and smiled as they walked past. Haloren engaged them in Swahili, getting laughs out of several. Some of the Maasai were texting on cell phones, getting current cattle and mango market prices from town-an odd mix of the modern and the traditional.

Haloren kept pace easily alongside her, encumbered as she was.

“You mind helping with this gear?”

“I would, but I’m a firm believer in the equality of my female colleagues. Hey, speaking of that: Doesn’t Adwele already have a mother?”

“Yes, but he’s missing a father.”

“You applying for the position?”

“Back off, Bruce. He’s a smart kid, and he’ll need all the help he can get. Babu didn’t leave much behind.”

“I’m just curious whether you’re doing it for Adwele or for yourself. You will be leaving at some point, you know.”

McKinney studied Haloren for a moment, then nodded as she realized he really was just looking after Adwele’s best interests. “I get what you’re saying, but Babu was a good friend. He kept me safe on more than a few research trips. If I can help his family, I will. Even after I go home.”

Haloren studied her too. Then he stopped suddenly. “All right, then. I’ll leave you to it.”

“Hey!”

Haloren turned.

“I promise not to tell anyone you’re not really an asshole.”

He saluted before heading off. “Much appreciated.”

She smirked, shaking her head as she watched him fall in alongside another researcher heading in the other direction.

McKinney hung in an arborist saddle sixty feet above the jungle floor. A cacophony of tropical birds and vervet monkeys echoed in the trees around her. She shaded her eyes against sunlight glittering between the leaves overhead and examined the tree’s crown, looking for weaver nests. Fortunately she didn’t see any.

The lowest branches of this Outeniqua yellowwood tree-or Afrocarpus falcatus — were still twenty feet above her. Her rope hung down from a branch even farther up. She had launched a throw line over it with a crossbow and hauled her climbing rope up after it, securing both ends using climbing knots and a dual line technique she’d learned as a grad student to hook up her harness.

Readjusting her position, McKinney gazed out across the jungle from this hilltop tree at the densely forested peaks of the Usambara Mountains still shrouded in mist in the distance. There was an immense diversity of sights and smells. It was always breathtaking up here. She never failed to notice how beautiful these mountains were, wrapped in low cloud cover and jungle canopy-humid and profuse with life. Reveling in the natural world was as close to the spiritual as McKinney got. She knew it was on this continent-possibly in this very jungle-that the first hominids arose, beginning the journey that separated mankind from the other animals. Becoming self-aware. She felt humbled by the vast stretch of history this place had seen.

She looked down to track the progress of her companion, a sinewy African boy of about ten. He, too, wore a rock-climbing helmet and sat in a climbing saddle suspended from a separate rope. He was laboriously working his way up-his booted foot looped through a rope stirrup. The boy grunted as he pushed up with his leg, ascending another few inches, then readjusting his knots.

McKinney pointed. “Don’t grab the Blake’s Hitch, or you’ll lose ground. Keep your hands below it. That’s better, Adwele. Good.” She smiled at him. “How you holding up? Need a rest?”

He shook his head. “No, miss. I’m good to go.”

She nodded. Adwele was always good to go, ready to learn something new. Unafraid. “Don’t push too hard. Take your time and concentrate on form.”

He glanced down. Then looked up, flashing a white smile. “Look how high we are!”

“Check that out…” She leaned back on her rope and pointed at the hills. “This is the way birds see the Amani.”

Adwele looked out at a view he’d never seen, though he’d lived his entire life here. A grin spread across his face.

McKinney could see the wonder in his eyes, his growing fascination with the natural world. She saw so much of herself in him. It gave her pause.

A maternal pang was all it was, she knew. The lost decade of her postdoc work, the long hours and low pay of an associate professor. While other people were settling down, she’d been traveling in the remote regions of the world doing field research. It was an adventurous life, but not one suited to being a parent. Besides, there were already enough people in the world, and what she was leaving behind for future generations was her research. She took a deep breath.

“Let me see how your knots are holding up.” She walked the tree trunk to come alongside him. McKinney checked Adwele’s rig section by section. “Stopper knot’s still solid. Nice bridge. Figure-eight looks good.” She examined the Prusik knot wrapped around the main line and pushed the loops more tightly together. “Was this slipping when you ascended?”

“A little.”

“Keep it snug like this, and it won’t slip even if the rope gets wet.” McKinney glanced below them. “About time to add another safety knot too. Every ten feet. Remember.”

“Yes, miss.” Adwele nodded and deftly tied a slipknot into the rope that trailed away beneath him. There were similar knots at intervals in the line below.

She rapped on his helmet with her gloved hand. “You’re becoming a pro. Now, remember, it’s important to follow all of the steps. What happens when we get careless?”

“Hospital or worse.”

McKinney nodded. “Yes. Very good.”

“Why does Professor Haloren use a metal tool to climb instead of all these knots?”

“You mean an ascender? Because Professor Haloren is lazy.”

Adwele laughed. “He says you’re cheap.”

“Equipment can malfunction, and when it does, you’d better know how to do this yourself. Once you can tie these knots without thinking, you can use an ascender if you like.”

Adwele was already gazing past her, up into the tree’s crown. He pointed. “Look, a kipepeo.”

McKinney followed his arm to see a pink, parchmentlike butterfly flexing its wings on the leaf of a nearby tree. “ Salamis parhassus. Also called ‘the Mother of Pearl Salamis.’”

Adwele took a small notebook and pen that hung by a short cord to a carabiner on his harness. He flipped through the pages and entered a tick mark. He counted. “Fourteen more than last year so far, and there’s still a month to go. Is it the butterfly farmers at Marikitanda?”

“Could be. Although it could also be because you’re surveying more.”

Adwele nodded as he put his notebook away. “My sister says I cannot become a scientist. She says it is a white man’s job, but I told her that you’re a woman, and you are a scientist.”

McKinney gave him a serious look, then planted her feet firmly on the tree trunk, far above the jungle floor. “Do you know why I love science, Adwele?”

He shook his head.

“Because science is the best tool we have for finding truth. For instance, to the naked eye you and I look very different, but it took science to help us see that there’s almost no genetic difference between us. And that’s a great truth. Remember that.” She slapped him on the helmet playfully. “It’s what you put in here that counts.” And she poked him in the chest. “And what’s in here. Don’t let anyone ever tell you you can’t try for something, Adwele. No one knows what you’re capable of yet-not even you.”

“Yes, miss.”

“Time to head back.”

He nodded.

“What’s the first step when descending?”

Adwele thought for a moment, then looked down to the base of the tree. He cupped a gloved hand over his mouth and shouted, “Down check!”

McKinney looked down to see an Amani Reserve ranger named Akida wave back and give a thumbs-up.

“Clear!”

She looked back at Adwele. “Okay, good. Remember, we do this slow and steady so we don’t overheat the rope. Two fingers on top of the hitch, with your control hand holding the line. Depress the Blake’s Hitch lightly, and remove the safety knots as we reach them…”

Walking the mile or so back to the research camp, McKinney shared the load with Akida, but Adwele insisted on carrying his own pack, struggling as he went. McKinney kept a short length of throw line over her back in a European coil and turned back to watch Adwele.

Navigating around a tree, Adwele started falling backward with the added weight. “Help me, miss!”

McKinney grabbed his rope bag and helped him reseat it on his shoulders. “You got it?”

“I’m good.”

She exchanged grins with Akida, the Amani ranger who brought up the rear. They could both see traits of Babu in the son.

They continued walking the path home. Adwele walked behind her. “My mother says you are too pretty to keep your hair short. You should let it grow so that you can find a husband.”

“Uh, thanks for the advice, but I’m in Africa to do research. And where I come from, women don’t need to rely on a man for a living.” She pointed down at driver ants swarming in a thick line along the edge of the path. “Look.”

Adwele stopped to watch the swarm. “Siafu.”

“Yes.” McKinney pointed. “Do you know that almost every ant you see is female?”

“Even the siafu warriors?”

McKinney nodded. “That’s right. All of the workers, the warriors, and the queen, they’re all girls. The nursery workers determine the caste of the young by how they feed them, but the only time they make boy ants is when they want to create a new colony.”

“Then they need boys sometimes, eh?”

McKinney laughed. Adwele never missed anything. “I guess that’s true. C’mon, smart guy…” She held out her hand to keep them moving. Her gaze happened on a large raven observing them from a tree branch overhead. She was surprised for a moment until she realized that the Amani no doubt held more than a few ravens. Perhaps she was only just starting to notice them.