Bruce McPherson

Wojtek Behnke, 36, has trained his flock of ewes to follow a drone  CREDIT: ANDREW FOX/ANDREW FOX

Wojtek Behnke, 36, is getting his 300-strong flock of breeding ewes to follow the airborne device by giving them nuts at the same time as it flies overhead.

Farmers have previously tried to make their herds afraid of drones by programming them to emit a barking sound, which encourages them to walk away from the noise in the desired direction.

But the clever beasts quickly cotton on to the fact that the drone is not going to hurt them and start ignoring it.

To tackle this impasse, Wojtek decided to use positive reinforcement.

This is the first time a farmer has used this method to tackle the centuries-old conundrum of how to speedily and efficiently herd sheep.

"I was looking on the internet and saw drones were being used to herd sheep so I though 'let's give it a go' and it worked," Wojtek told The Telegraph.

He teamed up with his sister's colleague Mark Rutter, professor of Applied Animal Behaviour at Harper Adams University, who was pioneering the positive reinforcement method.

Together, they hatched a plan to train the ewes to associate the drone with food. 

Wojtek set up a tube going into a trough in the sheep's field and hid behind a hedge, secretly dropping food down it while flying the drone overhead. He stayed out of sight so the sheep didn't end up associating him with food rather than the drone.

Eventually, the sheep started coming to the trough when they heard the drone even if there was no food. This then led to them following the drone around.

The method harks back to the work of Russian physiologist Ivan Pavlov who used positive reinforcement to train dogs to associate particular noises with food.

Professor Rutter told The Telegraph: "Farmers traditionally get sheep to move by either putting a dog behind them or getting sheep nuts. Sheep learn it's a nice tasty treat and will follow you. But if they're spread out over a large area then they're probably not going to hear you shaking the nuts.

"The drone frightening mode quickly becomes ineffective the more you use it.

"Sheep are prey species and responsive to possible threats. They are described as stoic and don't want to give away that they're injured - something prey animals exhibit - because if predators think they can't run away as quickly, then they'll target that sheep.

"They run away from the drone initially then quickly realise it's not a threat and ignore it. But the more positive reinforcement is used, the more effective it becomes.

"It's certainly time-saving and would help improve the welfare of millions of sheep across the country."