"But if they are cooperating it would certainly be an interesting problem."

He looked at her sharply. "Open-ended research like that is not for graduate school. You need to pick a problem with a definite answer, or you'll never finish. The university can't afford to keep on supporting doctoral candidates indefinitely, you know."

"But if I wanted to test the hypothesis that they were cooperating, what would you suggest...?"

Can't hurt to ask his advice.

He stood up to return to the research center. "That's pretty obvious. Duplicate the conditions, observe carefully, and record the data meticulously, the way I've taught you for enclosure research. But it's a waste of time. Stick to your enclosure observations. Ground squirrels are inherently more interesting."

"I'll do it on my own time. And thanks for the advice." A good graduate student must always be submissive.

Branton strode off, waving his hand vaguely behind him in response.

Amy Chang, another first-year graduate student, grimaced at his retreating back. "Ground squirrels are inherently more interesting," she muttered in a low voice that aped his didactic tone. "What an a.s.shole."

Janice suppressed a smile. She also didn't share Branton's enthusiasm for the endlessmate-subst.i.tution experiments he was conducting in the enclosure. Few of the graduate students did. Still, that was her summer grant money.

Amy brushed black bangs out of her eyes. "For what it's worth, I believe you. The chipmunks have always seemed to be brighter than the ground squirrels anyway."

As if on cue, a chipmunk began its alarm cry from the tree a few yards away. They were sitting outside, in a small clump of pines close to the lab buildings that functioned as a rustic picnic area. Janice studied the ground next to the log she was sitting on: large black ants were busily combing the fallen pine needles. "Nature's garbage collectors," she said. "Without ants, we'd be knee deep in dead moths."

"They're great scavengers, all right," agreed Amy, "and what a system they have: a lot of unremarkable individual units that together make an unstoppable army. And they find everything that's edible. There's no hiding from them."

"You know, in a way, those ants make me think of the chipmunks. If they were organized like ants, how would we live with them?"

"What do you mean?"

"Think about it-you know what a nuisance ants are at a picnic. What if an organized group of chipmunks descended on a table full of food?"

Amy paused. "Hm. I'll bet they could carry off most of the stuff without much trouble."

"Right. And do you know what would happen if someone tried to stop 'em?"

"Dunno, what?"

"They'd be picking teeth out of their hand. Rodents are pretty aggressive. Despite what Branton said, they don't hesitate to attack an animal much larger than themselves. Look at this." She showed Amy the scar on her finger-two white semicircles left by the sharp incisors of a harmless-looking white lab rat.

She remembered her surprise at the rat's unprovoked attack.

"I remember reading that rats in slums bite sleeping babies. Even kill some of them," said Amy.

"Yeah, and during plague years in Europe the rats crunched the bones of the dead bodies."

"Ugggh. But those were rats."

"Chipmunks are just rats with stripes, bona fide rodents with all that implies."

"Yes, not like my birds. Even sea gulls are better mannered than rats."

"Oh yeah? Remember that Hitchc.o.c.k movie about a lot of birds attacking the people in a little town?"

"Oh, that one. I read somewhere how they trained all those birds to peck people. But it wasn't real.

There wasn't any reason for them to act like that all of a sudden."

Janice let out a deep breath she didn't know she'd been holding. "I always thought it was a frightening movie, to have benign creatures suddenly become threatening. And what I saw today was real. Those chippies really weren't very friendly. I'd hate to go into the woods alone if large groups of any kind of rodent were out looking for trouble."

" 'The Attack of the Killer Chipmunks' eh?"

"It sounds silly, but that's because we've been conditioned by Disney cartoons to think of them as lovable, harmless little creatures."

"Well, you have to admit they're pretty cute."

"Only if you romanticize them. Take those d.a.m.ned ground squirrels, for example. If the females get too upset at living conditions, or if they're caged with a strange male, they kill their young. Bite off their heads."

Amy shuddered. "You're really serious about this rodent menace, aren't you?"

The chipmunk continued to call from the tree. Janice lobbed a pine cone at it halfheartedly.

"Well, before I get too carried away I need to prove what I saw. Branton said to duplicate the conditions."

"So throw them some more snakes."

"Huh? Oh, you mean road kills. Yeah, there must be plenty. Maybe when Jeff comes up he can find some."

Late that afternoon, Janice was working in her cubicle in the lab when she heard a familiar male voice outside her open door. "Janny babe? You in there?"

She leaped up from her chair and flung herself at the tall, lean, and slightly disheveled figure in the doorway. "Jeff! Wow, you got here fast! And it's so good to see you." They were instantly in a mad whirling embrace around her cubicle.

Amy chose that moment to knock on the doorframe. "Hey, cool down, you two. I can hear you giggling all the way down the hall."

Jeff slowly put Janice down, sliding her body down his while staring intently at her. Finally her feet were on the floor, and she disengaged from him slightly. Still hugging him, she turned to Amy and introduced them. "Jeff, meet Amy, the Pellet Researcher for this year."

Jeff looked blank. "Pleased, I'm sure. What are pellets?"

Amy sneezed. "Barf b.a.l.l.s. Birds that prey on small furry things cough up b.a.l.l.s of fur and bones. I separate out the bones and identify them. We even find snake scales in 'em."

"Oh yeah, sure. I just couldn't connect for a moment." He collected himself. "It's the alt.i.tude, you know. My brains are at eight thousand feet. Besides, I was distracted."

Amy grinned. "Okay, I get the hint. But when you're ready, I've found something about the chipmunks you should know."

Despite herself, Janice was intrigued. "Tell me quick, then we can talk about it later." She hugged Jeff. "Much later."

"Well, basically, this summer's big owl pellets have quite a few chipmunks in 'em."

Janice looked puzzled. "What's that mean?"

"There shouldn't be chipmunks in these pellets-they're diurnal animals. They're not active when the owls are out, so how can they be getting caught?"

"Something's funny."

"Not only that, but I checked the pellet results from past years-up until two years ago, only voles and mice, nice nocturnal animals, what you'd expect. No chipmunks."

"Well, either these are early owls, or the chipmunks stay up late."

"Exactly. And there are no reports of funny owls. So the chipmunks are changing their behavior."

Over the next week Janice and Jeff retrieved a variety of squashed and b.l.o.o.d.y carca.s.ses from the paved roads between Mammoth Lakes and SNARL and transported them to the site of her encounter with the chipmunks, just north of the intersection of Highway 203 and Highway 395, on an old asphalt spur road within sight of the interstate. Her jeep began to smell like ripe flesh, and her gloves acquired unpleasant stains.

Thursday morning she dumped yet another squashed rabbit on the edge of the pavement. Then she retired to her jeep on the side of the road and waited, binoculars and notebook at the ready, for the chipmunks to respond in the now-familiar pattern. Jeff pulled out a book and stretched out in the back seat.

Within minutes there was a stirring in the low shrubs nearest the carca.s.s. Two chipmunks she called the Look outs emerged from the vegetation and approached the rabbit. They circled it cautiously, sniffing the air repeatedly and making low chittering noises. At some unseen signal they flashed quickly back into the shrubs. Next came the noise of high-pitched barking: not the continuous alarm signal common to chipmunks and squirrels, these were short bursts of sound repeated for about ten minutes. This was followed by the appearance of at least a dozen chipmunks around the carca.s.s. Finally came the feeding frenzy, enthusiastic yet curiously disciplined. Some animals tore out chunks and disappeared into the shrubs, to be replaced by others. In about an hour the rabbit was reduced to fascia-covered bones.

"Let's see Disney make a cartoon out of this. They could call it 'Bambi and Thumper Share a Roadkill,'" she remarked.

"Reminds me of stories about piranhas."

"Land piranhas? But they take living prey. These are more like furry vultures. At least so far."

"Oh? Care to explain?" He put his book down.

"Okay. I think they're cooperating because that way they can compete with bigger scavengers likeravens and coyotes. These carca.s.ses disappear so fast the other creatures never have a chance to find them."

"Why do chipmunks eat meat anyway? They're supposed to eat nuts and berries and stuff like that.

They're not predators."

Janice sighed. "Deer, squirrels, mice, rabbits and other cute, furry critters are cla.s.sified as plant eaters, herbivores. We've adopted the view fostered by cartoons and kids' books, that they only eat plant food. But actually, very few animals turn down the chance to eat meat even if they don't hunt."

"Why?"

"Well, for starters, meat is easier to digest than plant food. No tough fibers. Carnivores have much shorter, simpler digestive systems than herbivores. So it's a good source of energy and calories."

"So why haven't chipmunks everywhere realized this before?"

"Good question, especially from a mathematician. It has to do with the evolutionary pressure. It's pretty fierce up here."

Jeff looked blank.

"Look, this is a food-scarce environment. Dry all year and cold in the winter to boot. The pine forest where the chipmunks live is not very diverse-not a lot of different organisms, but many individuals of the few species that do thrive here. It's the cla.s.sic pattern for a difficult environment."

"But there are twenty square miles of pine forest filled with pine nuts-how tough can that be for a chipmunk?"

Janice considered for a moment, pawed through some papers in the front seat. She tossed Jeff a greyish object.

"Look at this deer leg I found in the forest."

He turned the bone over and noticed that one end was jagged.

"Let's see...it has marks on it-looks like tooth marks. Okay, it's been gnawed."

"Yup. Nothing lasts long on the forest floor. When an animal dies its body is quickly scavenged by the living. Even the bones are gnawed for their calcium. So anything the chipmunks can do to improve the food supply is going to be a big advantage for their survival."

"Okay. I'm convinced. But I'm just a humble mathematician. How're you going to prove your idea to the Brantons of the world?"

"Well, I don't know yet, but I think I can predict what the next step is. It's the same kind of thing that happened to our own ancestors on the African savanna. We were originally scavengers, cleaning up after the big predators like lions."

"So much for the Great Hunter idea, eh?"

"It's not a very likely scenario for puny creatures like us without claws or fangs, or at that time, much technology. The point is, a coordinated band can scare or hara.s.s a large predator away from its kill."

"But our ancestors did start to hunt."

"They did at some point. Using the same pack behavior they developed for scavenging, they found they could take large living game. And the communication skills they needed for hunting led to human language."

"So the next step for the chipmunks is to talk?"

"No, silly." She bopped him lightly on the head with her clipboard. "Wolves and wild dogs don't talk, but they hunt in packs. So, I predict that the chipmunks are going to hunt living prey."

Janice swam up out of sleep with the comforting sensation of another body next to hers. Jeff was snuggled up against her, breathing deeply and surprisingly quietly, one arm draped over her b.r.e.a.s.t.s. She ran her hands lightly over his exposed shoulders and arms. He stirred, grunted contentedly and opened his eyes. Then inhaled deeply and coughed. "Can't get used to the air up here-how can you breathe something you can't even see?"

"Smoghead. Look out there. It's a gorgeous day. Let me show you some scenery."

"What are we doing about breakfast?"

"There's a good place in Mammoth, then we can explore the forest behind the town."As they drove out of the parking lot they pa.s.sed Amy carrying a paper sack. She waved them down.

"Hey, how'd you like to come out hooting with me tonight? I want to nail down if Owl #6 is a Great Grey. I found some pretty interesting-looking feathers in its territory."

"Is that what you've got in the bag?" asked Janice.

She frowned. "No, unfortunately. These are the remains of Old Reliable, my owl from Doe Ridge. I found it lying under the tree where it leaves its pellets."

"How'd it die?"

"Can't tell, actually. The body was pretty well munched already-not much but feathers and a few bones left. Things sure don't last long on the forest floor around here. I checked the site just two days ago."

Janice turned to Jeff. "You have time to go hooting tonight? I'll bet you've never done it."

He suppressed a smile. "Sure, if it's a hoot, I'm interested."

They all groaned.

"Okay, we're in."

"Great. I'll bring the hot chocolate. Meet here around eight tonight and we'll head off."