Cunning squirrels make bogus burials of 'nuts and seeds' to fool onlookers

Their quick intelligence, razor-sharp memory and ruthless cunning have made them a foe of gardeners everywhere.

Now it turns out that grey squirrels are even more devious than anyone realised.

To protect their winter food stocks from potential thieves, they put on an elaborate show of burying non-existent nuts and seeds, a study has shown.

Scientists say the fake burials are designed to confuse any rival squirrels, birds or humans who might be watching.

The level of deception has astonished animal experts who say it shows a rare form of animal cunning and intelligence.

Squirrels are great hoarders and bury or hide spare morsels of food in the autumn for the lean winter months.

Dr Michael Steele, of Wilkes University in Pennsylvania, has found that they are also capable of elaborate deception, New Scientist reports.

He found that a fifth of all so-called food burials are fake - and the proportion goes up if they think they are being watched.

"To our knowledge, this is the first study to show evidence of behavioural deception by a rodent, and the first to use an experimental approach to studying deceptive behaviour in in the wild," he says.

The squirrels go to elaborate lengths to keep up the pretence of hiding food.

Once they have dug a small hole in a flower bed, woodland floor or lawn, they act as if they are thrusting a small object into the gap.

They complete the deception by covering the fake cache of food with a layer of soil or leaves.

The incidence of fake burials goes up when they think their food is under threat.

Dr Steele recruited a group of undergraduates to follow the squirrels and find out where they were burying food. The number of bogus interments shot up as soon as the human volunteers began to raid the food stocks - suggesting that the creatures were becoming even more deceptive as a reaction to the raids.

He believes that the bizarre behaviour suggests a far more advanced thought process for grey squirrels than scientist previously thought.

But experts are divided on whether the latest research means they are capable of reason or whether they simply get into routines which work for them.

Dr Lisa Leaver at the University of Exeter said: "They may just have learned through trial and error that certain behaviours protect their food from theft."