Dr Andrew King of Swansea University has used GPS technology to understand how sheepdogs do their jobs so well.
He fitted a flock of sheep and a sheepdog with backpacks containing extremely accurate GPS devices designed by colleagues at the Royal Veterinary College, London. Daniel Strömbom of Uppsala University and colleagues then used data from these devices, together with computer simulations, to develop a mathematical shepherding model.
The team found that sheepdogs likely use just two simple rules: to collect the sheep when they’re dispersed and drive them forward when they’re aggregated. In the model, a single shepherd could herd a flock of more than 100 individuals using these two simple rules.
Andrew King explained, “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. 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.”
Daniel Strömbom said, “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.”
King believes that the research team’s model will have many applications for tasks like crowd control, herding of livestock, and keeping animals away from sensitive areas. The algorithm developed could be used to program robots for these tasks.