RAPTOR RED

RAPTOR ATTACK APRIL

A pair of fierce but beautiful eyes look out from the dull green undergrowth of conifers and ferns that bound the edges of mud flats and riverbeds. The eyes follow every movement among the great herd of plant-eating dinosaurs that mills around in the open meadows, feeding high in the trees, and sniffing the air for danger. The eyes belong to a young adult Utahraptor, a female who has not yet reproduced.

The female Utahraptor moves her twenty-foot-long body quietly through the ferns, walking in long, slow strides on her muscular hindlegs. She stops every few steps, rotates her elongate head, surveys the plant-eaters. Her eyes move back and forth, executing the rapid scanning of a hunter who is thinking about everything she sees. She is an intelligent killer. She watches the pattern made by the huge herbivorous dinosaurs. She evaluates each individual as a potential victim.

If she could put her thoughts into a human language, they might be: That cow over there is too alert -she travels with two near full-grown calves. They’re too strong, too dangerous to attack.

And that young bull is part of a bachelor-pack, five adolescent males who are aggressive and inquisitive. We can’t kill them today.

The Utahraptor moves her muzzle slightly to the left. She searches the treeline for another pair of eyes.

There! She exhales in a short, barely audible grunt. Her eyes meet those of another Utahraptor, a young male. He has the same stocky, compact torso she has, the same long, low head, the same neck held in an S-curve, the same long arms and fingers tipped with cruel-looking claws.

She is half of a mated pair, locked together in Darwinian monogamy for the last six months. Their mutual attraction is evolution’s way of giving both male and female the best possible chance to get their genes into the next Utahraptor generations. In nature, nothing else matters.

As the days have lengthened in the early spring, the female Utahraptor has been responding to a powerful shift in her own internal chemistry. During the winter she was hunting for herself and for her mate. But now, subconsciously, she’s aware of a new responsibility. She is hunting for the next generation. Soon they must build a nest and they must raise chicks.

The female and male exchange glances again, and she nods to him. It’s a message that means, In the next few minutes our lives will depend upon each other. I’m with you.

The raptor pair-bond is held together by these shared risks. If they’re efficient as a pair - and lucky - they’ll be uninjured and well fed at the breeding season. Then and only then will there be a brief interval for copulation.

This is the most dangerous season for raptors. Mating and rearing young exposes both parents to the highest risk of injury and death they’ll face all year. Hunting alone isn’t good enough. A pair of raptors hunting together is four or five times more successful than a solitary predator.

The raptor pair have another reason to be anxious. They are newcomers to the Utah ecosystem, an immigrant species whose original home is thousands of miles away in northern Asia. The native prey species of North America have strange habits and may be equipped with defenses the new predators have never seen.

The female Utahraptor sniffs the dung heaps left by the plant-eaters at the edge of the treeline. She’s searching for identification chemicals, clues to the nature of the animals she and her mate are stalking. She’s reluctant to risk an attack on a herbivore whom she has never met. But she’s optimistic today - the dung-aroma seems familiar.

She has learned that she and her mate often have the advantage in the new land - sometimes the native prey species haven’t had time to evolve special countermeasures against the foreign hunters. Invading predators may hit new territory like a Darwinian blitzkrieg.

The female raptor sticks her narrow snout out between the dried fronds of a tree fern. The dull brown-red hue of the fronds matches her own body color. She sniffs the air, testing the prey’s chemical signature - she trusts identification by smell more than by sight.

I know this one. We’ve hunted it before. We can do it if we’re careful. Her thought processes click through her predatory options. She knows her mate is smart. She trusts that he knows what she knows.

There. That one. That bull acting alone, bullying the cows. He’s not paying attention - we can kill him. The female raptor silently selects the target, wordlessly evaluating the bull’s vulnerability.

Her thigh muscles begin to twitch. It’s almost time. They’re almost close enough.

She pauses one last time, sitting up inside a clump of tall tree ferns. She looks back again at her mate. They’re too close to their prey to exchange nods, but just looking at each other is reassurance enough.

Her target is the biggest of the herbivores in the Utah ecosystem, an Astrodon (star tooth), a bronto-saurian species with a long neck, a long tail, and a torso built like a ten-ton elephant’s.

Giant size confers a certain ecological arrogance, and astros have a swaggering disdain for predators. In the astro’s mind, any carnivore would be foolish to attack. Millions of years of evolution have built into their brains the comforting knowledge that they face hardly any real threat from meat-eaters. The only giant carnivore species is the ridge-backed acro, Acrocanthosaurus, but these three-ton hunters are very rare.

Even if a full-grown acro did try to attack an astrodon herd, the combined defenses of a dozen astros, totaling more than a hundred tons of enraged vegetarians, would be impregnable.

As the astro herd ambles easily around the edges of the salt lake bed, their big cushioned paws churning up the briny mud, brains routinely check sensory input for danger. No scents are alarming. They pick up the hint of a raptor a hundred yards away, but raptors are eighty-pound predators that wouldn’t dare challenge a twenty-thousand-pound bull astro. The resident raptor species is the commonest predator in the astros' world, and the big plant-eaters see or smell them every day. All the raptors are tiny compared with the star-toothed brontosaurs. Never would the biggest raptor, a 150-pounder, even dream of attacking astros, unless it was lucky enough to find an unguarded newborn calf.

There is a raptor pack ahead, chewing up the carcass of a five-hundred-pound plant-eater (an iguanodont species), but they slink away when a cow astro makes a mock-charge in their direction.

The astro brains go down their genetically programmed checklist for sounds. There’s no cause for alarm coming from this sensory system either. A low undertone of crunching can be made out to the left, under some conifer trees, where a one-ton armor-plated nodosaur is feeding placidly on seedlings. No threat here - the nodosaur moves away when a young bull astro pushes through the trees to investigate.

The big astro eyes, built like hawks' eyes, the size of dinner plates, make rhythmic sweeps of the landscape, stopping to focus in on any movement. Yes, there is a second group of raptors two hundred yards to the right. A different species. But at a hundred pounds, still too small to worry about.

It’s late summer, the time when big bull astros start to joust with each other to impress the females. Dull thuds punctuate the hot still air as the bulls swing their necks, giraffe style, like flexible clubs, aiming blows at each other’s heads.

And it’s a time of new danger for the astros: There’s a newcomer to the resident fauna, a species who has reached Utah after coming across the North Pacific land bridges from its Central Asian homeland.

The bull astrodons pick up the novel scent - the unmistakable aroma of a raptor species, just a little different from the three species the astros are used to. Strange odors usually jingle alarm in any animal’s brain. A strange odor means a creature never met before, a creature whose danger potential hasn’t been evaluated through experience.

But the bull astrodons ignore the new scent. Their danger signal is overridden by their sexual competitiveness, their springtime drive to get the most desirable mate. Hormones are kicking in, actuated by their internal clocks.

Astros have no genetically coded alarm for raptor odor, and the foreign species is giving off merely a new variant of raptorine smell. Millions of years of evolution have built into astro psyches a disdain for these puny predators. Darwinian processes can never prepare any animal for a totally new danger - natural selection gives it only the best response to dangers faced by its ancestors. And not once in their pedigree have adult astrodons suffered a serious loss from a raptor attack.

That evolutionary rule is about to be broken. The cow astros, always more cautious than the bulls, begin to bunch up, surrounding their yearling calves and stretching their necks to catch a glimpse of the raptor that is emitting the strange scent. Cows take no chances with their young, their genetic investment for the next generation.

Two bulls neck-wrestle with wild abandon, clunking each other about the eyes and ears. They don’t pay any heed whatsoever to the new raptor scent, which has now grown very strong. They don’t notice that they are far from the main herd. Their brains are pounding out the same message again and again: Beat this bull, beat this bull, beat this bull, get a cow. In the Darwinian game, bulls must take chances. The females reject most suitors, choosing only the strongest and most vigorous, so a bull will literally risk life and limb to impress a desirable mate.

The cows stop looking at the bull contest. All the cow eyes focus in the direction of the foreign smell. Their minds have switched over to calf-protection behavior. And the cows see what the young bulls don’t. The cows see the attack coming across the lake bed.

The cow eyes follow the light glistening over the broad scales on the thighs and calves of the giant raptors running noiselessly over the hard mud. The bulls still are totally absorbed with their sparring. They don’t see the foreign raptors until the horrible hand claws cut long gashes through their skin and muscle.

Messages of pain jump from the bull astros' skin to their brains. They experience the disconcerting sensation of their own blood dripping down the skin of their stomachs. Now at last the switches flip over in their brains. Switched off are all thoughts of mating. Switched on is terror of an attack more vicious than any they have ever experienced before. One bull manages to break away in a terrified running walk. He screeches high-pitched notes through the sound-making chamber that bulges around the nostrils on his snout. The cow herd screeches in response. The matriarchs bellow in deep warning tones and swoosh their tails from side to side.

The other bull stares at its attackers - a pair of raptors ten times heavier than he has ever seen before. The bull can see and smell his own blood on the three hooked claws carried on each raptor forepaw. Conflicting impulses flood his brain: flee, counterattack, run, or try to crush these new horrors with his front feet.

The raptors attack again from either side. Their long forearms extend outward, and their claws catch the bull’s skin. As soon as a raptor feels its recurved claw tip penetrate the skin, the hand muscles contract instinctively, driving the claw-knives four inches deep into the flesh. Biceps and pectoral muscles flex to the max, pulling the claws through the prey’s body, ripping channels a yard long.

The bull stands stupefied. Pain from two dozen long claw gashes on right and left flanks is overwhelming the normal feedback loops in his central nervous system. No one cut is life-threatening. But the cumulative effect drains his strength.

Again the two giant raptors attack. But this time the bull charges, hurtling his huge bulk forward, whipping his tail right and left. The raptors sidestep the counterattack. They reach out and slap their forepaws against the bull as he stumbles past, leaving a new set of bright red lines on his hide.

The bull is confused. He had won battles the year before with a one-ton ridge-backed acro. But that meat-eater was slow and clumsy compared to these quick-footed giant raptors. The ridge-backed acro had lunged at the bull, grabbing at the bull’s shoulder, trying to hold on with foreclaws shaped like grappling hooks. The bull had shaken off the acro and crushed it to death by pressing it against the ground.

The anti-acro tactics don’t work now. These giant raptors don’t try to grapple and hold on. Their fore-claws act like curved knives, cutting through hide and flesh. And the giant raptors don’t even try to bite: Each new attack is a quick dash and slash, a fast run-up to the bull and then a quick blow by the ginsu-knife claws.

And there’s another frightening difference about this attack. These giant raptors are smart.

The bull astro has a brain much too small to form the concept of smart. And yet, in an instinctive way he realizes that the two raptors are attacking as one unified enemy. Each fresh attack is coordinated. As one raptor slashes at the right shoulder, distracting the bull, the other raptor strikes from the other side.

The astro brain clicks over to the last-ditch defense tactic: panic and headlong retreat.

The bull bellows. His legs crack through the hard, white saltcrusts lying over the deeper parts of the lake bed. He stumbles, falling to his knees. The stinky sulfurous black mud below the saltcrust oozes up his calves. Up again on his feet, he smashes through the pterodactyl nests clumped together at the lake bed’s center. Tne air becomes a crimson, fluttering curtain as a thousand red-winged pterodactyls take off, screaming and pecking at the bull as they leave their eggs.

A possibility of escape - a feeling of hope - develops in the bull’s brain. The center of the lake bed is covered by five feet of dark odoriferous mud, sediment stained by the slow decay of dead leaves, dead clams, and dead fish. It’s mud that clings to your feet and sucks your legs down. Surely the raptors will hesitate to follow.

The bull sloshes into the deepest part of the lake bed and looks around - the raptors are gone. His body weight presses his legs further into the muck. He has a hard time lifting his hindpaws up because they support most of his weight. He can move his forepaws, but he can’t turn.

Calm settles onto his astro brain. Five minutes elapse. The pterodactyls begin to return. They are quiet as they float back down onto their nests.

Pink-tinged pterodactyl bodies surround the astro. Another five minutes go by. A gentle rustling from behind draws his attention. Some creature is carefully threading its way among the nests. When a pterodactyl snaps its beak and wigwags its wings in protest, the creature freezes.

Another creature is walking slowly into the lake from the other direction. It too stops each time the pterodactyls erupt in a screeching commotion.

The bull tries hard to make out the scent. But the aroma of the fetid black mud overwhelms the olfactory bulbs in his brain.

One of the creatures jumps up onto some abandoned pterodactyl nests, perching atop the yard-high structure of hardened mud. It’s a giant raptor. It’s only a dozen yards away.

The other raptor hops onto another nest, five yards away.

The two raptors stare at the bull. They are silent and still, a slight tremor visible in their calf muscles.

The fatal attack comes in slow motion. On both sides the giant raptors step carefully from one dry pterodactyl nest to another. They converge toward the front of the bull astro, where he can’t reach them with blows from his tail. The predators pause, rock gently side to side, and leap.

The bull shudders under the weight - both raptors are clinging to the top of his shoulder blades. He roars and tries to bite them, but his neck won’t twist around far enough.

The fatal strokes don’t come from the raptors' hands. The killing blows come from the inner toe of the hindleg, a claw shaped like a Gurkha knife. The raptors drive their hindclaws deep into the bull’s side, carefully placing the claw tips between his ribs. The entire hindquarters of the raptors tense up as the thigh, calf, and back muscles generate immense tension, then explode in a spasmodic contraction.

The sharp-edged hindclaws slice deeply through the body wall of the bull, powered by nearly the entire muscle mass of the raptors. Gaping wounds five feet long expose his vital organs to the outside. The raptors strike again and again, carving up the still-living mass.

Down onto his knees and wrists, the bull collapses. Shock and trauma close down his central nervous system. The bull dies slowly, as the raptors watch from their perch on the edges of his hip bones.

The raptors wait. They’ve seen supposedly dead prey suddenly come back to life. The astro is too large for them to take chances, so the predators watch to be sure the breathing has stopped in the body below their feet. Then they start to feed, plunging their long snouts into the warm carcass, pulling out hunks of liver.

Only a half hour elapses before both raptors are gorged. They squat down onto a pterodactyl nest, right next to the astro carcass. They catch the scent of small raptor species circling at a safe distance, hoping for a chance to rush in and steal part of the kill.

The male Utahraptor stands up to growl at a little predator. That is the first mistake the giant raptors have made all day.

The dead astro, still lying upright on its elbows and knees, falls over onto its side. The inert mass of the torso pins the male raptor’s tail in the black muck. For the first time since they attacked the astro, the raptors are frightened and disoriented. The fallen raptor, the male, thrashes about but succeeds only in dislocating a hip and sinking further into the mire.

The female raptor shrieks and grabs his arm in her mouth, trying to pull her mate by the arm. But that action fails too - it rolls him onto his side. His face is smothered by mud. He tries to clear his nostrils but can’t.

The desperate struggles exhaust the trapped raptor - he can barely keep his mouth above the surface of the suffocating mud. His mate cries piteously. She tries to dig out the mud from underneath his head. It’s hopeless. Her sharp claws cut through the mud but can’t shovel it out.

Her own hindfeet are beginning to sink through the surface of the mud flat, now churned up and liquefied by the frantic actions of the dinosaurs' feet. She doesn’t know what to do. Nothing works. Nothing in her learned experience is helpful; nothing in her instinctive repertoire.

Finally her sense of self-preservation overcomes the pair-bond, and she retreats to a bit of high ground. In ten more minutes the trapped raptor is dead, his body totally submerged in the dark sediment.

The female raptor sits stunned for hours - she has just lost the mate she had chosen for life. They had hunted together successfully two dozen times. They made two dozen kills without either raptor being injured in the slightest. She does not know what to do.