Human children acquire vocabulary at an astounding rate. Beginning around age two, they learn about 10 new words a day. Studies have shown that they can instinctively learn the name of something even if they have not heard the word before. Now a German border collie named Rico has demonstrated that children are not unique in this ability.

Researcher Julia Fischer of the Max Planck Institute for Evolutionary Anthropology in Leipzig says Rico was able to learn the name of a toy after only one exposure to it.

"It shows that the basic way he acquires this knowledge is probably comparable to that of three-year-olds," she says.

Ms. Fischer and her colleagues report in the journal Science that they tested Rico's ability to learn new words by placing a new toy among seven familiar ones for which he knew the names. The canine's owner first asked it to retrieve an item the dog knew. Next, the owner asked Rico to fetch the new toy, using a name the animal had never heard before. Ms. Fisher says the dog correctly retrieved a new item in seven out of 10 sessions.

"So he was now confronted first with a new word and there was a new thing, and then he was apparently able to figure out that the new word referred to the new item, the new toy, and he brought it. So he can do simple logic," she explains

The researchers do not claim that Rico and human children have an equally rich vocabulary, but they do show the dog can link objects with sounds.

In a written statement, Science magazine's editor for life sciences, Katrina Kellner, says this ability suggests that brain structures supporting such learning may have formed the basis of some kind of advanced language abilities in humans.

The dog has a 200-word vocabulary, about the same as language-trained chimpanzees, dolphins, sea lions and parrots. However, Rico is the first animal to be tested for its ability to figure out the name of something without having heard it or seen the object before.

Ms. Fisher says dogs' long history of domestication might have enhanced their vocabulary abilities.

"Certainly it does help that dogs have been bred to attend to humans and that is something that has been selected for in many dogs," she adds. "But I think, nonetheless, in principle we would be able to find this in other animals as well."

The German scientists plan to put other animals through the same tests.