The Globe and Mail

He may be a dog genius. But a Border collie named Rico with a vocabulary of 200 words is challenging the belief that humans have a unique way of learning language.

German scientists, who discovered Rico on a game show, say he quickly learns new words, such as sea horse, tiger or panda, the same way toddlers do.

He appears to pick up new words after hearing them only once, a process called fast-mapping, which allows children to add words to their vocabulary even if they just overhear an adult using them. Up until now, researchers had thought this was a uniquely human ability.

No, Rico doesn't speak.

"You don't have to be able to talk to understand a lot," says Julie Fischer, a German researcher with the Max Planck Institute for Evolutionary Anthropology in Leipzig.

Her research appears to back up dog owners, especially those with Border collies, who say their pets have a knack for learning words.

"I picked a Border collie because I wanted one little creature in my life to listen to me," says Evelyn Cheesbrough, an Ottawa dog owner with two children.

Dr. Fischer and her colleagues caution that their work involves a single dog. It could be that nine-year-old Rico is brilliant, or that he belongs to a breed with an exceptional ability to learn words, or that the early training he received from a German family makes him different from other dogs.

Since he was 10 months old, his owners have trained him to fetch more than 200 items, mostly children's toys, upon request.

Dr. Fisher noticed Rico on a popular German game show in which he surprised viewers with his large vocabulary. She approached his owners and began her research by verifying that the dog did indeed understand 200 words.

She put the 200 items with which he was said to be familiar into 20 random sets of 10 toys each. For each set, Rico was asked to fetch two randomly chosen toys -- for example, a dinosaur and a red ball -- from another room from which he couldn't see his owner.

He got 37 out of 40 right. This gave him a vocabulary comparable to that of apes that have been trained for years to understand language, and to dolphins and parrots.

But the next two experiments put him on par with humans, at least very young ones. Rico was asked to fetch an unfamiliar item -- for example, a bunny -- that was added to a group of seven familiar toys. He was able to pick out the new toy seven times out of 10, apparently because he understood that the familiar items already had names.

Four weeks later, he was tested to see if he remembered the new objects. Could he pick out the bunny, choosing from a set of toys that included four completely new toys and four familiar ones? In six tests involving different new toys, he picked the correct item half the time, comparable to the performance of three-year-olds in similar experiments. Tested 10 minutes later, he got it right four times out of six.

The findings, which were published in today's edition of the U.S. journal Science, suggest that brain structures that support this kind of learning may not be unique to humans.

There are, however, clear differences between language acquisition in humans and dogs. Toddlers have a much broader knowledge than Rico about the meaning of words, the researchers say, and can distinguish between words that convey meaning on their own, such as nouns and verbs, and those that don't, such as articles.

Rico also can't speak, and at nine years old knows just 200 words. Human nine-year-olds know tens of thousands of words, and are learning 10 new ones a day, says Paul Bloom, a psychologist at Yale University who wrote a companion piece on Rico for Science.

More experiments are needed. Dr. Fischer and her colleagues are investigating whether Rico can understand entire phrases, for example, "Put the bunny in the box." In an interview, she said her team is planning to study the vocabulary of other Border collies and other breeds of dog.

Not all may have the same linguistic aptitude. An unscientific survey of dog owners at an Ottawa park found that their pets know anywhere from 37 words to none at all.

Warren Coutts owns two greyhounds, former racing dogs he adopted. He says they understand just a few words, but are smart, and quickly adapted to a quiet home life as pets. "They are smart in a socially adaptive way."

Jeannie Wynne-Edwards isn't sure her Great Dane, Daisy, understands any words. She used to think that was because Daisy grew up in a francophone family before moving in with her. She has tried speaking to her in French, to little effect.

"She's ineffective in both languages."