"This is going extremely well," Levine said, rubbing his hands together. "Far beyond my expectations, I must say. I couldn't be more pleased."
He was standing in the high hide with Thorne, Eddie, Malcolm, and the kids, looking down on the valley floor below. Everyone was sweating inside the little observation hut; the midday air was still and hot. Around them, the grassy meadow was deserted; most of the dinosaurs had moved beneath the trees, into the cool of the shade.
The exception was the herd of apatosaurs, which had left the trees to return to the river, where they were now drinking once again. The huge animals clustered fairly tightly around the water's edge. In the same vicinity, but more spread out, were the high-crested parasaurolophasaurs; these somewhat smaller dinosaurs positioned themselves near the apatosaur herd.
Thorne wiped sweat out of his eyes and said, "Why, exactly, are you pleased?"
"Because of what we're seeing here," Malcolm said. He glanced at his watch, and wrote an entry in his notebook. "We're getting the data that I hoped for. It's very exciting."
Thorne yawned, sleepy in the heat. "'Why is it exciting? The dinosaurs are drinking. What's the big deal?"
"Drinking again," Levine corrected him. "For the second time in an hour. At midday. Such fluid intake is highly suggestive of the thermoregulatory strategies these large creatures employ."
"You mean they drink a lot to stay cool," Thorne said, always impatient with jargon.
"Yes. Clearly they do. Drink a lot. But in my view, their return to the river may have another significance entirely."
"Which is?"
"Come, come," Levine said, pointing. "Look at the herds. Look how they are arranged spatially. We are seeing something that no one has witnessed before, or even suspected, for dinosaurs. We're seeing nothing less than inter-species symbiosis."
"We are?"
Yes," Levine said. "The apatosaurs and the parasaurs are together. I saw them together yesterday, too. I'll bet that they're always together, when they're out on the open plain. Undoubtedly you are wondering why."
"Undoubtedly," Thorne said.
"The reason," Levine said, "is that the apatosaurs are very strong but weak-sighted, whereas the parasaurs are smaller, but have very sharp vision. So the two species stay together because they provide a mutual defense. just the way zebras and baboons stay together on the African plain. Zebras have a good sense of smell, and baboons have good eyesight. Together they're more effective against predators than either is alone."
"And you think this is true of the dinosaurs because…"
"It's rather obvious," Levine said. "Just look at the behavior. When the two herds were alone, each clustered tightly among themselves. But when they're together, the parasaurs spread out, abandoning their former herd arrangement, to form an outer ring around the apatosaurs. Just as you see them now. That can only mean that individual paras are going to be protected by the apatosaur herd. And vice versa. It can only be a mutual predator defense."
As they watched, one of the parasaurs lifted its head, and stared across the river. It honked mournfully, a long musical sound. All the other parasaurs looked up and stared, too. The apatosaurs continued to drink at the river, although one or two adults raised their long necks.
In the midday heat, insects buzzed around them, Thorne said, "So where are the predators?"
"Right there," Malcolm said, pointing toward a stand of trees on the other side of the river, not far from the water.
Thorne looked, and saw nothing.
"Don't you see them?"
"No."
"Keep looking. They're small, lizard-like animals. Dark brown. Raptors," he said.
Thorne shrugged. He still saw nothing. Standing beside him, Levine began to eat a power bar. Preoccupied with holding the binoculars, he dropped the wrapper on the floor of the hide. Bits of paper fluttered to the ground below.
"How are those things?" Arby said.
"Okay. A little sugary."
"Got any more?" he said.
Levine rummaged in his pockets and gave him one. Arby broke it in half, and gave half to Kelly. He began to unwrap his half, carefully folding the paper, putting it neatly in his pocket.
"You realize this is all highly significant," Malcolm said. "For the question of extinction. Already it's obvious that the extinction of the dinosaurs is a far more complex problem than anyone has recognized."
"It is?" Arby said.
"Well, consider," Malcolm said. "All extinction theories are based on the fossil record. But the fossil record doesn't show the sort of behavior we're seeing here. It doesn't record the complexity of groups interacting."