But still, as strong as the approaching prey’s sonars were, the rays’ ampullae of Lorenzini were even stronger. Their ampullae had a range of five miles and could detect the electrical activity in every one of the approaching animals’ muscles: front and rear torsos, necks, fins—even their hearts. Indeed, from five miles away, the juvenile rays had detected the prey’s individual heartbeats, more than fifty of them.
The rays knew the prey’s sonars would soon pick them up as well, but the prey’s sonars could be fooled. If a small pack of rays swam in a very particular way, they could effectively simulate another predator that the prey would attempt to evade. But in evading what they’d think was a single large predator, they’d actually be swimming toward thousands of smaller ones. A group of juveniles began moving.
FIFTY BOTTLENOSE dolphins zoomed out of the sea, their elegant gray bodies glistening in the pale moonlight. The mammals hung in the air for a brief moment, arching slightly, then knifed back in. A few miles offshore and moving at nearly twenty-five miles per hour, the dolphins were in the midst of a southern migration.
At the front of the herd, the leader was much larger than the rest— a twelve-footer weighing nearly 950 pounds. The animal had been studying the ocean ahead since the beginning of their migration, and until this point, its sonar had detected very little, just schools of tiny fish. But suddenly it picked up something else. The reading was foggy and unclear, but somewhere in the distance was a large creature. Made of cartilage, the creature appeared to be a shark, swimming from the west. The leader changed direction slightly, and like a flock of birds, the other dolphins followed.
They swam for nearly half a minute when the leader picked up something else: an unmoving mass spread out over a square mile. Again the reading was unclear, but the leader’s sonar indicated it had to be a kelp forest. Dolphins often swim through kelp forests to evade sharks, and this school intended to do the same.
They swam straight for it. What they thought was a kelp forest was a little more than a mile away.
CHAPTER 21
THE DOLPHINS had reacted as hoped.
Most of the rays still didn’t move, however. They just floated, luring the mammals closer. They knew that if the dolphins didn’t change course soon, their fates would be sealed.
THE DOLPHINS didn’t change course. They knew instinctively that something was “off” in the ocean ahead, but they didn’t know what. As they knifed in and out of the sea, the leader’s sonar continued producing unusual readings. It now indicated the kelp forest ahead might not be kelp after all, but something else, something indeterminate. The big dolphin didn’t have time to analyze it. The large cartilaginous creature from the west was still swimming toward them, and now so was a second creature, from the east.
To escape both, the dolphins had to swim right into the middle of the forest. Either that or turn around. They didn’t turn around.
THE BLACK eyes watched them. A single ray too far from the herd to participate in the hunt floated listlessly just below the surface as the dolphins leaped out. Through the shimmering water, it watched them, a sight to behold, their silhouettes flying through the night air beneath the moon. The predator saw none of their beauty. It saw food.
THE LEADER’S sonar readjusted again. Now there were four large cartilaginous animals. One to the east. One to the west. And two directly behind them.
The big mammal now knew that the mass in front of them wasn’t kelp at all. But whatever it was, it wasn’t exactly in front of them either. Not entirely. Somehow, it had moved and changed shape. It was now on their sides.
And even behind them.
THE RAYS quickened their pace. They had drifted into position earlier to avoid detection, but now they were swimming as fast as they could, approaching from every angle.
THE DOLPHINS halted.
Floating ten feet below the surface, they tuned carefully. Something had surrounded them, apparently a vast group of animals. At first, the dolphins had determined they were sharks, but sharks moved much faster and were shaped differently. These were winged creatures.
The mammals fanned their tails, rising toward the shimmering surface until their heads poked out. They still couldn’t see the rays, but their sonars reconfirmed that they were coming. And also that they had teeth. Very large teeth.
Suddenly the dolphins knew what was happening. They were being hunted.
Smart as they are, dolphins are not courageous animals. They scare easily and often lose their ability to behave rationally when threatened. Floating at the surface, a few twitched ever so slightly. Then their twitches grew larger, turning into jerks. Then the jerks turned into full-torso shakes. Then one of them cried, a single high-pitched squeal that echoed over the watery plane. Then a few more cried. Then they all cried. Suddenly the entire herd was shrieking and shaking wildly. The attack hadn’t even begun, and the once-graceful, once-intelligent animals were already reduced to a mindless, terrified mass, sheep before the slaughter.
Then a powerful, piercing scream rang out above all the others. It was the leader. Unlike the others, it hadn’t moved and hadn’t made a sound. Its strong, 950-pound body was still pointed forward, its head out. The others went silent and swam next to it, forming a straight line.
They slowly submerged to ten feet. A hanging wall of gray, they just read the signals surrounding them. They still couldn’t see the rays but knew the winged creatures were moving closer. They’d never get close enough.
The gray wall moved. Slowly at first, as the dolphins searched the waters in every direction. They saw no fish of any kind, just twisted shards of moonlight. They picked up speed very quickly and within moments were streaking through the seas.
Continuing, they looked up and, for the first time, saw two of their hunters a pool length away near the surface, winged silhouettes slowly flapping toward them.
The dolphins sped below and past like they weren’t there.
The rays froze. The dolphins had panicked earlier and been on the verge of self-destruction. Now they were putting up a fight. And a good one. They just watched as the speeding mammals disappeared.
The dolphins didn’t look back. The moon-dappled waters ripped past, and they veered sharply upward. They couldn’t see them yet, but their sonars indicated the next group of rays, a dozen, was two pool lengths away. The rolling surface rose up, and they hurtled through it. Bathed in the moonlit air, they breathed in deeply, then knifed back in. A dozen winged silhouettes came into view moments later and the dolphins simply tore through the sea beneath them. As they passed below, one of the dolphins looked up. Their hunters weren’t even moving now. The rays’ silhouettes were frozen, so still the dolphin instinctively thought they might be dead.
They weren’t dead. They were looking right back at it, studying it, studying all of them. Their horned heads turned slightly, watching the gray mammals disappear. The rays were too smart to waste energy chasing prey they knew they couldn’t catch, but they instinctively realized there might be another way to catch the dolphins. It was too late for these rays of course but perhaps not for the next group. . . .
THE NEXT group of rays was already within the mammals’ view, two dozen of them. Strangely, these rays were swimming away from the dolphins, toward the surface.
The dolphins ripped below and past them, already arching up for the next gulp of air.
MANY POOL lengths away, more than a hundred rays were also swimming toward the surface, the water surging past their horned heads. The previous group’s timing had been off, but these rays sensed theirs could be perfect.
THE DOLPHINS hurtled through the seas, moving at nearly forty miles per hour now. Their heartbeats had already slowed considerably. The next group of rays was the last major obstacle. If the dolphins could make it past them, they’d soon be free. . . .
THE RAYS swam higher as fast as they could. The dolphins were rapidly coming closer and within seconds would pass directly below this exact spot. The predators pumped hard
, the shimmering plane approaching. They pierced it and, spraying water everywhere, rose straight into the night air. Ascending to different heights, they turned back to the sea. The undulating gray bodies were speeding closer, moments away. The rays just had to hang in the air long enough and then . . .
THE DOLPHINS were suddenly confused. The rays had disappeared. Speeding through the moon-dappled waters, the mammals turned in every direction. They couldn’t see them anywhere.
THE RAYS were directly above them now. Plunging down, eyes locked. Just like seagulls hunting for fish.
SUDDENLY THE dolphins picked something up. Something above the water.
They didn’t have time to react.
Suddenly big winged bodies were dropping everywhere. Ten landed in front of the herd, a dozen behind it, and they all missed. But half a second later, another platoon landed, and they were on top of them.
Powerful jaws thundered closed on the dolphins’ defenseless bodies, gouging huge chunks from their backs, necks, torsos, and faces. The speeding gray wall disintegrated, shrieking dolphins swimming off in every direction. The mammals thrashed furiously, desperately trying to shake off their attackers. None let go. The rays had wrapped their entire winged bodies around them, and as they were hurtled through the seas their frantically chomping jaws simply tore off more and more meat.
Within minutes, more than half the herd had given up, resigned to death. Others, even though chunks the size of footballs were missing from their sides, tried to swim away in vain. Five dolphins actually shook their attackers off, but soon others leaped on.
Two of the mammals were in such shock they dove toward the depths, not realizing they wouldn’t have enough air to get back up. They didn’t need it. Bleeding severely as they passed the thousand-foot mark, their muscles suddenly stopped working. They entered complete paralysis and, within seconds, drowned. Their corpses floated for a moment until a dozen of the rays they’d passed earlier began to eat them.
The largest dolphin, the 950-pounder that had been the herd’s leader, continued to fight. A few feet below the waterline, it swam as fast as it could, less than five miles per hour now. Seven juvenile rays were tearing away at it, three on its back, two on its stomach, and one each on its face and neck. It swam for another twenty feet, then gave up. It emitted a final cry, a weak gurgling sound, and died. The rays continued to feed on it. They’d already removed 350 pounds, and though their stomachs were full, they worked on the 600 pounds that remained.
But suddenly they stopped.
They leaped off the floating piece of meat and swam away.
Something was coming. Something much larger and considerably more dangerous than they were. One of the adults had left its hiding place in the depths and come to steal their spoils. The smaller animals couldn’t see it yet, but they sensed it. They had first sensed it rising twenty minutes earlier but had been so focused on the hunt, they’d ignored it. But the massive animal was too close to be ignored any longer. They wouldn’t challenge it. If it wanted their food, it would have it—and without a fight. They swam farther from the corpse and looked down. Never before had the juveniles seen an adult come to the surface, not once. An adult that would do so had to be on the verge of starvation. Its massive pumping body slowly appeared below. The juveniles backed farther away still. They didn’t want to be close to it.
They drifted lower, glancing up at the watery moon. Then the gargantuan form rose up in front of the white orb, its curtain-size wings slowly flapping. When the animal reached the floating piece of meat, its purpose was unmistakable. A pair of jaws wide enough to swallow two men whole stretched open, then thundered closed, severing the dolphin in half. The jaws quickly chewed and the animal swallowed.
The juveniles didn’t move.
Another corpse, an inedible infected one, they had determined, was floating nearby. The huge creature swam toward it. Again, the jaws opened and thundered down. But this time, there was no chewing. The creature sensed what the juveniles had: the meat was infected. It deserted the severed pieces and dove down, descending toward the darkness.
After the great animal was gone, the smaller ones returned to the surface. As they edged their horns out of the sea, they heard it: faint, high-pitched screams echoing across the watery plane. A few of the slaughtered dolphins were still alive, hanging on, their cries an offering of fresh meat to whoever could reach them first. This group wasn’t interested. Their stomachs were filled, and they were too tired to swim. They wanted to rest before they continued north again. They slowly descended. Then, floating like a cluster of enormous starfish, they simply closed their eyes.
The ocean’s surface became perfectly quiet. The only sounds were from the wind and the waves. The cries of the dolphins were no more.
CHAPTER 22
IT WAS 7:30 A.M. on this day in the first week of October. The sky was a bleak gray, without a trace of sun anywhere. Good fishing weather. Three tuna fisherman, Don Gilroy, Kurt Hicks, and Mark Balson, had been trailing a pack of seven dolphins for an hour and were now in the waters off of Santa Cruz, a few miles north of Monterey. Tuna fisherman regularly followed dolphins to help them locate their catch. Biologists still didn’t know why, but dolphins and tuna often swam together, dolphins near the surface, tuna a couple hundred feet below it.
The gods appeared to be smiling on the fisherman this morning because the dolphins abruptly stopped swimming forward and began circling. This was unusual behavior. Normally, dolphins slow gradually as they tire. The men didn’t suspect there might be a reason for this. They’d seen relatively few dolphins recently, so now that they’d actually found a small pack, they weren’t asking questions.
The fishermen let out a massive weighted seine net. It drifted down to the tuna below, caught them, then began to tighten and ascend. In compliance with the Marine Mammals Protection Act of 1972, the men watched carefully as one by one, all seven of the dolphins leaped over the net and swam away. In less than a minute, the mammals were gone—apparently. The three had to be certain. The Marine Act had a second procedural requirement stipulating that someone had to paddle out in a rowboat and physically check that every dolphin had escaped. Many fishermen regularly ignored this rule, but not Gilroy, Hicks, and Balson.
Balson had gone last time, so Gilroy and Hicks flipped a quarter to see who would go now. Kurt Hicks lost. Paddling out in a tiny rowboat in his overalls, he noticed a single strand of kelp, oddly shredded, but didn’t give it much thought. He reached the middle of the net, then rolled into the sea with a mask. Holding it against his face, he scanned for any stray dolphins.
Back on the boat, on a peeling wood plank that doubled as a bench, Balson and Gilroy made small talk.
“So what do you got going this weekend, Gilroy?”
“Ah, nothing much. Watch the baseball game, get drunk with Darlene.”
Balson chuckled and glanced toward Hicks. “What’s Kurt doing out there anyway?” It normally took all of ten seconds to confirm the dolphins were gone, but it had already been longer than that.
“Ah, who knows, probably playing with himself.” Gilroy stood. “Hey! What are you doing out there, Hicks?!”
Kurt Hicks raised his sopping head from the water. “There’s something down here! I’m gonna go see what it is!” He put the mask on completely and disappeared.
Gilroy sat. “So, what do you got going this weekend, Balson?”
“Ah, I’ll probably watch the ball game myself. Maybe the Giants can win one, huh?”
They continued to chat casually for another minute when Gilroy realized that Kurt Hicks still hadn’t come back up. He eyed the empty rowboat nervously. “Think he found a dolphin tangled in the net or something?”
Balson hesitated. “I only counted seven and I thought I saw every one of them swim off.”
“Maybe there was an eighth we didn’t see.” Gilroy checked his watch. “Let’s give him another thirty seconds.”
Exactly twenty-five seconds later, Kurt Hicks st
ill hadn’t come up.
Gilroy stood. “Son of a bitch. Maybe he did get tangled up down there. All right, I’m gonna go get him. . . .” He ripped off his shoes, grabbed a life preserver, stood up on the gunwale, and . . . Kurt Hicks popped up, gasping for air.
Gilroy shook his head. “What the hell were you doing down there, Hicks?!”
Kurt Hicks didn’t answer. He frantically swam toward the rowboat.
“Hey, are you all right?!”
Again, Hicks didn’t respond. He just swam to the little boat.
Gilroy put binoculars to his face and saw that something was behind Hicks, swimming after him.
Hicks swam as fast as he could—but not fast enough. The thing was getting closer.
He reached the boat and climbed in.
Then Gilroy realized that whatever was behind him wasn’t actually swimming. It wasn’t even moving. It just seemed to turn over when a wave struck it. But what was it? “What’d you find down there, Kurt?”
Hicks paddled forward as fast as he could, still not answering.
That’s when Gilroy realized. It was a dead dolphin.
Gasping for air, Hicks climbed onto the boat and collapsed on the peeling wooden deck.
Natural Selection Page 10