Why did the chicken really cross the road?

We might never know why the chicken crossed the road, but at least we now have an idea how it dodged the traffic.

Scientists have discovered that the domestic fowl find their way around using a sophisticated navigational system based on the position of the sun.

They also display signs of well- developed social intelligence - and quickly learn from other's mistakes.

While their name is synonymous with cowardice, the evidence suggests that chickens are far from birdbrains.

Researcher Christine Nicol said: 'They definitely have hidden depths.'

In an experiment, chickens were challenged to find their way through a maze to reach food. It was clear from the way they learned the correct route that they navigate by the sun, even over short distances.

'When people ask why did the chicken cross the road, we say we don't know but it might have been navigating by the sun,' said Professor Nicol, unveiling her research at the annual meeting of the British Association for the Advancement of Science at Leicester University yesterday.

They are thought to have inherited their navigation system from their wild ancestor, the Asian jungle fowl. It is similar to that of other, migratory bird species.

In another test, chickens were taught to peck either a red or a green button a certain number of times to gain their reward of food.

Another set of chickens were allowed to watch, before trying to get at the food themselves. It was found that the second set of birds got a meal much faster after learning from the first group.

'They may be bird brains, but we need to redefine what we mean by that,' said Professor Nicol, of the University of Bristol.

'Chickens have shown us they can do things people didn't think they could do.' She said research on chicken intelligence should give clues to hens' welfare.

'We eat 800million chickens a year in this country, and eggs from 40million hens,' she said. 'The work we are doing sounds trivial, but we keep more chickens than any other farm animal and we have to take decisions about how we treat them.

'We need to know how deserving they are of our care and our sympathy, and to do that we need to know how their minds work, and their capacity to feel and fear.'

Not to be outdone, sheep and pigs also have more to them than just a woolly coat or a distinctive grunt, the meeting was told. Tests found that sheep are almost as good as humans at picking out faces.

They can remember 50 members of their flock, and up to ten familiar humans, for more than two years.

Brain scans found that ewes even think of a missing lamb if they hear a recording of its cry.

Professor Keith Kendrick, of the Babraham Institute near Cambridge, said: ' They can learn to recognise faces very quickly.'

The scientists suggest their findings indicate that moving sheep to different areas or mixing flocks could be cruel.

Pigs have shown they are capable of cunning behaviour by following their farm colleagues to steal their food.

Dr Mike Mendl, of the University of Bristol, told the meeting: 'They can develop quite sophisticated social competitive behaviour, similar to that seen in some primate species.'

He said the research could help to tackle aggression in pigs, which causes deaths and injuries costing farmers about £20million a year.