Until now, talking horses have only existed in fiction.

Instead of directly communicating, riders have to interpret whinnies and neighs with their own intuition.

But now scientists have trained horses to communicate precisely using symbols.

Horses in an experiment have been shown when they feel cold and need a blanket by pointing with their heads to a symbol – a horizontal black line. If they wanted their blanket taken off they pointed to a vertical line and for no change, a blank symbol. Stock image

THE CLEVER HANS EFFECT The researchers took precautions to guard against the possibility which is known in horse training circles as the 'Clever Hans' effect. A horse called Clever Hans won world-wide fame for being able to answer maths questions asked of him – which he would answer by stamping his feet the correct number of times. It was later shown that his trainer was subtly indicating the number of times he needed to stamp his feet. The study's authors say that unlike with Clever Hans, there was no 'right or wrong' answer for the horse as it would be rewarded with a carrot for whichever choice was made. Also, the horses' heads and ears were focused on the symbols in front of them, and the choices were made without hesitation. Advertisement

Horses in an experiment have been shown when they feel cold and need a blanket by pointing with their heads to a symbol – a horizontal black line.

They were also able to communicate two other possibilities: that they wanted their blanket taken off - a vertical line, or 'no change' – a blank symbol.

The research in Applied Animal Behaviour Science found 23 horses in the trial learned the task after training for just 10 to 15 minutes a day over two weeks.

The horses were taught to associate putting the blanket on and off with the symbol by being rewarded with slices of carrot.

And the researchers found the selection of the symbol was not random, but was dependent on the weather.

Horses opted for a blanket when the weather was wet, windy and cold.

Cecilie Mejdell, of the Norwegian Veterinary Institute and colleagues carried out the study.

To test whether the horses had learnt the meaning of the symbols, they were let out of their paddocks for two hours, to become fully aware of the weather.

All horses had a blanket on and had to choose between 'blanket off' or 'no change'. In the two winter situations left (and right picture) both horses touch the blank 'no change' display board

The symbols were hung up on a fence in front of each horse, and the horse was released, and their trainers stepped aside. Poltergeist (pictured) touches the board with the 'blanket off' symbol

Choice made by horses for blanket status is illustrated at days with very different weather conditions

The symbols were hung up on a fence in front of each horse, and the horse was released, and their trainers stepped aside.

The horse then approached and made one touch with the muzzle.

On cold days, around 5°C (41°F), the horses chose to put on a blanket, and they chose not to on warm days when the temperature was around 23°C (73°F).

'The horses used their new insight to communicate their preference regarding blanketing in order to obtain or maintain thermal comfort,' the authors wrote.

'Based on their individual perception of weather including ambient temperature, wind and precipitation.'

'In conclusion, horses can learn to use symbols to communicate their preference regarding blanketing,' the authors write.

The researchers warned that they could not be 100 per cent certain the trainers were not subtly influencing the horses.

But they took precautions to guard against the possibility which is known in horse training circles as the 'Clever Hans' effect.

Symbols were presented on white painted wooden display boards (35 × 35 cm). To the left, the horizontal bar meaning 'put blanket on', in the middle the blank board meaning 'no change', and to the right, the vertical bar meaning 'take blanket off'

A horse called Clever Hans won world-wide fame for being able to answer maths questions asked of him – which he would answer by stamping his feet the correct number of times.

It was later shown that his trainer was subtly indicating the number of times he needed to stamp his feet.

The study's authors say that unlike with Clever Hans, there was no 'right or wrong' answer for the horse as it would be rewarded with a carrot for whichever choice was made.