Scientists have discovered that sheepdogs use two simple mathematical rules to round up large herds of sheep. The team, including scientists from Swansea University, said that their findings mean robots could be developed to effectively herd sheep, now that they know secret of the dogs' herding abilities.

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Scientists used GPS technology to track sheepdogs' movements, in a bid to understand how they perform their jobs so well, and how they manage to coerce larger groups of sheep into moving together.

Researchers from Swansea, led by Dr Andrew King, fitted a flock of sheep and a sheepdog with GPS devices designed by specialists at the Royal Veterinary College. Colleagues at Uppsala University in Sweden then used the data generated to develop a mathematical shepherding model.

They said that their model was the first to succeed where others have failed.

The two rules identified by the team are: collect sheep when they are dispersed and drive them forward when they amass in a group. In essence, explained Dr King, sheepdogs gather together sheep when they see gaps emerging between individuals, and drive them forward once these gaps begin closing up.

King said the team had to think about what shepherding looks like to a sheepdog in the field to arrive at their conclusions, having first adopted a bird's eye view of the proceedings.

"If you watch sheepdogs rounding up sheep, the dog weaves back and forth behind the flock in exactly the way that we see in the model," Dr King explained.

"We had to think about what the dog could see to develop our model. It basically sees white, fluffy things in front of it. If the dog sees gaps between the sheep, or the gaps are getting bigger, the dog needs to bring them together," he said.

Daniel Strömbom, from the University of Uppsala, added, "At every time step in the model, the dog decides if the herd is cohesive enough or not. If not cohesive, it will make it cohesive, but if it's already cohesive the dog will push the herd towards the target."

The scientists claimed that their findings could be used to develop robots to herd animals; one shepherd could herd a flock of 100 or more sheep, based on the rules they identified and a computer simulation. They also said the research could have applications for crowd control or cleaning in certain environments (such as oil spills).  

However, as well as herding stray animals, working dogs are also resuming their role as guardians in a number of regions, including France, where the reintroduction of wolves to uplands areas has led sheep farmers to take measures to protect their flocks.

Jim Easton, chair of the International Sheep Dog Society, told Farming Online that the connection between sheepdogs and the animals they tend runs deeper than a set of commands.

Jim said, "I'm not saying it'll never happen [that robots herd sheep in some areas], but the border collie will never, ever be replaced on rugged hills. A sheepdog is not a machine; it's the power of their eye that gains respect from the sheep.

He continued, "They said when quad bikes came in that it could be the end for the border collie as a working dog. Nonsense. Some farmers herd with quad bikes, but it's not advantageous to the sheep or to them. You can chase sheep with all sorts of things, but with a sheepdog you can bring them in at whatever pace you like."

"These dogs have been used since 1700. They can work with cattle, horses, ducks, geese. A well trained farm dog will do the work of 15 men."

More information on the study is available from the Royal Society and a video of the mathematical model is available from Phys.org and the NERC.