Animals Do the Cleverest Things

The chimp who outwits humans; the dolphin who says it with seaweed; the existential dog

An elephant that never forgets its extended family, a chimp that can outperform humans in a sophisticated test of visual memory and an amorous male dolphin that likes to say it with flowers -- well, a clump of river weeds to be more precise. These are just some of the recent observations from the field of animal behaviour. They appear to show that there is no limit to the intelligence of animals, but what do we really know about the true cognitive powers of the non-human brain?

Experiments on wild elephants living in Kenya found that individuals can remember the whereabouts of at least 17 family members, and possibly even as many as 30. Tests in a laboratory in Japan found that chimps, and young chimps especially, have an incredible photographic memory. Finally, there was the story of the romantic river dolphins of Brazil. Males collected river weeds, sticks or even lumps of clay in their mouths to act as a form of sexual display to prospective mates. Scientists are convinced that it is not merely playful behaviour but a serious attempt at wooing the opposite sex with the cetacean equivalent of a Valentine's gift -- surely a sign of emotional intelligence.

The latest studies into the unusual behaviour of a range of species suggest that we should no longer assume that animals are just the dumb creatures that we've been led to believe since the days of St Thomas Aquinas, the 13th-century Italian monk whose moral philosophy formed the basis of our modern-day ethical treatment of animals. Indeed, scientists have found that animals are capable of all sorts of clever behaviour that we normally associate with human intelligence. They not only have good memories and a perception of the world around them, they also display feats of apparent far-sightedness and understanding that seem to go beyond the mental abilities of many people.

It used to be thought for instance that humans were the only tool-maker. Then it emerged that chimps in the wild have learnt to strip leaves off twigs, which they use to poke termite nests for food. Some years ago, scientists found that chimps, in fact, select a range of tools for different jobs, such as cracking nuts or carrying water. They were even found to pass on their knowledge to successive generations as a form of acquired, cultural inheritance.

Then last year, scientists revealed even more remarkable tool-making behaviour in chimps. They had video footage of chimps in the wild using a "tool kit" to dig for termites. A chimp would use a thick stick like a spade to dig a hole in the ground above a termite nest. It would then use a second, more delicate stick, which had been deliberately frayed at one end, to poke down through the open hole to search for termites, which would cling conveniently to the end of the frayed stick like peas on a dinner fork.

"These chimpanzees use something that doesn't happen anywhere else. They use a tool kit," explains Professor Andrew Whiten of St Andrew's University. "They use their hands and their foot to dig down, so they look like Mr McGregor with his spade digging down with great effort. We don't understand how possibly they could have worked out how to do that."

Even more remarkable tool-making was seen in the case of the New Caledonian crow. Oxford University scientists showed in 2002 that a particularly clever specimen of this species, called Betty, was able to fashion a hook out of a piece of straight wire and use it to "fish" for food concealed in a long tube. It was a bizarre demonstration of a basic understanding of cause and effect known as "folk physics". Even chimps have not shown such skills.

Another trait of intelligent life is being able to distinguish one creature from another but this has been taken to an extreme in the case of the biggest land animals. Elephants were already known to mourn their dead and to communicate with one another over long distances using barely audible, low-frequency growls. More recently, however, scientists have demonstrated that elephants in the Amboseli National Park in Kenya can distinguish between members of the two local tribes, the Maasai and the Kamba. A study found that the elephants became more nervous and wary when shown garments worn by the Maasai, whose young men sometimes spear the animals to prove their virility, but show no such behaviour in the presence of clothes worn by the Kamba.