Chaser (16 page)

However, the informal 1-of-8, 8-of-8, and 20-of-20 tests were subject to criticism that I was, knowingly or unknowingly, giving Chaser visual cues about which object to fetch. So every month I did a formal 20-of-20 test as well. I took twenty objects from her flock at random, reaching blindly into the plastic tubs where we kept them, and wrote their names down. After brief rehearsals with each of these twenty objects, I put them in another room so that neither Chaser nor I could see them and I could not possibly give her an unintentional visual cue about which one I wanted. And then I asked Chaser to go and fetch each one by name.

The first time we did this, Chaser got 18 of 20 right. Thereafter her performance on the formal 20-of-20 tests was consistently in the 90 to 100 percent range. In fact, she always got at least 18 out of 20 correct on the formal as well as the informal test. When she missed fetching an object by name in any 1-of-8, 8-of-8, or 20-of-20 test, I gave her additional training with that object alone, with no other toys in sight, before testing her again.

All told, our language training and testing sessions amounted to four to five hours a day. Weather permitting, I gave Chaser two to three hours of other physical activity a day outside the house. Some of the outdoor time was devoted to vigorous play with her named toys. But it also included agility play, tracking and stalking, and hikes in the nearby mountains.

In the backyard I set up an agility course with jumps, a tunnel, obstacles to crawl under, and stakes to weave in and out of. Chaser loved running the course, and my directions for her to run it in different directions and patterns were another opportunity to teach her words. Every run through the course ended with my sailing a Frisbee for her to catch triumphantly.

Some days we took the forty-minute drive to sixty acres of forest we own on the Tyger River, southwest of Spartanburg. Chaser loved jumping over logs and exploring under bushes as we hiked to a spot on the river with a wide bank of flat rock. This was perfect wading water for her to splash into while retrieving sticks and balls I tossed for her. Walking the land, she darted here and there to investigate animal scents, always on the move, until we climbed back into the car, where she curled up and snoozed until we got home, at which point she was ready for round two.

At five months old Chaser knew more than fifty words, including those for the basic obedience behaviors. More important than the number was that we were both having lots of fun and she was eager to herd more toys, and more names, into her growing flock. Outside of training sessions, she often initiated play with her named toys and loved engaging in activities with them that mimicked herding sheep. A sequence of chasing, catching, bringing back, and gathering together a group of toys was deeply involving and rewarding for her.

As Chaser approached six months of age, intensive practice was speeding up her word learning so that she needed fewer and fewer trials per word. I could see her response time—animal scientists call it latency—getting shorter and shorter between the moment when I said, “Chaser, find ___” and the moment when, eyes shining and tail wagging triumphantly, she brought back the correct surrogate sheep. She seemed to be learning words so quickly that I decided to try an extreme test.

I brought out a new object, a fleece-covered brown and white stuffed pony, about nine inches high and about fourteen inches from nose to tail. On the pony I had written the name Puddin. With Chaser sitting in front of me, I pointed to the stuffed pony and said, “Chaser! This is Puddin.” Then I immediately took it into the bedroom and placed it on the floor among seven other objects. Four were familiar objects whose names Chaser already knew, and three were novel objects she had never seen. Including three completely unfamiliar objects in addition to Puddin made the test very stringent, because it dramatically increased the possibility of error.

I came back in front of Chaser and asked her to find two of the previously learned objects, which she did without a hitch. There were still six objects on the floor in the other room: two familiar ones whose names she'd learned previously through repeated trials; three completely novel objects; and one, Puddin, that she'd seen and heard the name of only once. I then said, “Chaser, find Puddin.”

Chaser sprang to her feet and dashed into the next room. In another flash of fur she stood before me wagging her tail and grinning from ear to ear with Puddin in her mouth. I immediately tested her twice more, and four more times the next two days. Each time I put Puddin down among a different set of seven other toys. Each time Chaser was perfect.

There was no doubt about it. Chaser had learned Puddin the pony's name in a single trial. Identifying the new object correctly after hearing its name only once indicated that Chaser had achieved a form of referential understanding. Somehow she had grasped the idea that objects can have names. She had learned that my pointing to an object and saying “This is ___” meant I was going to announce the object's unique name. To use the terms of childhood language learning research, Chaser had learned two referential social cues for indicating word meaning. On top of associative learning she had now added at least the first stage of intuitive learning via symbols. This was supposed to be impossible for nonhuman animals.

Chaser's intuitively understanding that objects can have names was a defining moment for her as a learner. Chaser did not consciously realize what had happened, any more than eighteen-to-twenty-four-month-old toddlers consciously realize that they are suddenly understanding words in a new and fuller way. But I knew that Chaser had crossed a threshold and entered a whole new world of learning.

Random testing showed that Chaser could learn as many as ten new words a day, about as many as a nine-year-old child learns. Unlike a nine-year-old child, however, Chaser needed very extensive rehearsal time to retain this many words. So we settled into a pattern of one to two new words a day, which she could lock into long-term memory with a few days' worth of rehearsal sessions off and on through the day. Brief pilot testing suggested she could have learned three to four proper nouns a day, but I was also focusing on teaching her other elements of language, including common nouns and learning by exclusion.

At the age of seven and a half months, Chaser knew more than two hundred words, as many as Rico. That Chaser was now reading my mind through the words I spoke to her gave me goose bumps. It made me think of the moment when seven-year-old Helen Keller first understood the connection between words and the things they represent. For more than five years after a terrible fever left then nineteen-month-old Helen blind and deaf, she lived in darkness. She was almost like a feral child, subject to violent tantrums of frustration. Her desperate parents brought in twenty-year-old Anne Sullivan, herself nearly blind, to try to teach Helen. Every day Anne traced letters on the palm of Helen's hand, trying to communicate that these tracings spelled words that represented objects such as a doll she gave the little girl as a get-acquainted present.

Helen could not grasp that there was a word for everything and that everything had a word—or many words—to describe and represent it. In a rage at not being to able to understand what Anne meant by signing the letters
m-u-g
in her palm, Helen broke the doll that she was carrying everywhere.

About a month later, Helen and Anne were at a water pump on the Kellers' farm. As water poured over Helen's hand, Anne spelled out
w-a-t-e-r
on the palm of her other hand. Over and over again Anne spelled the letters:
w-a-t-e-r, w-a-t-e-r, w-a-t-e-r, w-a-t-e-r
.

Suddenly Helen burst out with a cry of joy. It was the defining moment of her life. The eyes in her mind opened and she saw that
w-a-t-e-r
meant the substance pouring over her hand, the substance she drank and encountered in other ways every day. Her genius at last set free, she was now on the path to gaining full command of language. Her learning exploded, and she grew up to become one of the most extraordinary and influential figures of the twentieth century.

Seeing Chaser's vocabulary increase day by day and week by week, I raised my sights from merely matching Rico to surpassing him. The goal for learning proper nouns was now a thousand words. A thousand-word vocabulary would be enough to show that Chaser's long-term memory system was extensive and robust. It was also enough to demonstrate her understanding of words as more than object names and in more contexts than simply fetching objects. If the skeptics didn't find Chaser's knowledge of a thousand proper nouns in combination with multiple common nouns and verbs convincing, they weren't going to be more favorably impressed by two thousand or three thousand proper nouns.

In the meantime I wanted to show Wayne West what a smart puppy we'd gotten from him, and I wanted to talk to him about giving Chaser a chance to herd sheep.

I put about twenty of Chaser's toys in the back of my pickup truck and drove out with her to Wayne's place late on a mild fall afternoon. It was Chaser's first return to the place of her birth. She was now almost her full adult size, about twenty inches high at the shoulder, but she hadn't filled out to her full weight and strength yet. She was still very much a puppy. I saw no sign that she recognized the surroundings or Wayne. But true to her social nature, she was delighted to get his warm welcome.

Wayne's backyard of nicely mown grass was separated by chainlink fencing from his kennel and barn area and the beginning of his pastures. Five sheep were in a large pen, about one quarter the size of a football field, next to his kennel. But Chaser paid no attention to the sheep or the dogs in the kennel as I got the plastic tub of her toys out of the back of my pickup and dumped them onto the grass. The appearance of her toys meant fun, and she kept her eye on her surrogate sheep.

Wayne watched in grave silence while Chaser retrieved one object after another by name and I directed her in herding-like play with them. Turning to Wayne, I said, “That's just a fraction of her learning. Right now she knows about two hundred words, and I'm thinking she can get to a thousand or more.”

Wayne cracked a smile and said, “Doc Pilley, you've got a lot of patience.” He wasn't at all surprised that a Border collie could learn a couple hundred words, and he didn't consider it a stretch for a Border collie to keep several hundred items straight in his or her mind. Working Border collies might have to distinguish individuals among hundreds of sheep from different flocks, and mingle or separate the flocks on command. He told me, “With you as a teacher, she'll hit the thousand mark and beyond. I don't have one iota of doubt about that. You're a dog man for sure, Doc.”

That meant a lot to me and emboldened me to ask, “You've got those five sheep over in the pen there. Do you think we could try Chaser on them? Do you remember you let me try that with Yasha when he was about a year old?”

“Vaguely.” Wayne smiled and added, “Now that you mention it, I seem to recall that Yasha had plenty of herding drive.”

Not having been born on a farm, Yasha had never even seen a sheep when I took him out to Wayne's. And I hadn't taught him the herding commands, as I had recently taught Chaser. When Wayne and I walked into the sheep pasture behind his house with Yasha, I excitedly said, “Yasha! Fetch the sheep.”

Yasha instantly took a wide arc out around the sheep. I said to myself, “By gosh, he has the instinct.” Yasha then rushed toward the sheep, and they bolted for the barn. A lamb couldn't keep pace, however, and Yasha blocked his path, ignoring the other sheep. I was about twenty-five yards away from the lamb in the opposite direction, and the lamb raced to me and pressed his body against me for safety. Yasha came up behind him and spontaneously dropped to the ground, in good Border collie fashion, about ten feet away. He was a natural, I thought.

Wayne laughed on being reminded of the details. “Chaser's young yet, Doc,” he said. “But I've seen dogs as young as twelve weeks old move sheep. And Arthur Allen started training his movie dog Nickey when he was four months old, because the dog was so darned precocious. Let's give it a try. But we both got to be ready to come to Chaser's aid. You've got to back a young dog up sometimes so they don't lose confidence.”

I put Chaser's toys back in the plastic tub and stowed the tub in the pickup. Wayne was waiting for Chaser and me at the gate to the sheep pen. Even as we approached the gate, Chaser showed no particular interest in the sheep, who were grazing in a loose cluster twenty or thirty feet from the gate. She'd enjoyed our play with the toys and she walked at my side, tail up and wagging slightly, ready for some more fun, whatever that might be.

We all went through the big swinging gate. Chaser and I remained just inside the gate while Wayne walked into the field at an angle until he was roughly equidistant from us and the sheep. I looked down at Chaser.

Aha! She was eyeing the sheep intently now.

“Chaser, go out,” I said.

She left my side and trotted out into the field toward the sheep, but kept twelve or fifteen feet distance from them, just as a Border collie should. When she was even with the sheep I said, “Chaser, come by,” and she circled around behind them. When she was directly opposite me on the other side of them, she stopped and dropped to the ground on her belly on my “There” and “Drop” commands. I asked her to “walk on” toward the sheep, and she did so, slowly but surely. When she was seven or eight feet from the sheep, four of them began to move away from her. But the fifth sheep, a large ewe, didn't budge, and the rest of the flock stopped moving and remained near her. Chaser kept coming forward, but her steps slowed.

Sheep get to know dogs, just as dogs get to know sheep. The big ewe had been herded by many dogs over the years, as Wayne worked his experienced dogs for visitors and customers and trained his young ones.

Chaser was only four feet away from the sheep. She was still moving in toward them, but only one careful step at a time.
Should I call her off?
I wondered. Her ears and tail were up, and she was focused on the sheep. I glanced over at Wayne. He was watching carefully but did not look concerned. So I said nothing.