A virtual fence for animals management in rangelands

Protecting biotopes and maintaining biodiversity are ecological aims highlighted in European policies. Grazing systems which have to adapt to these new constraints require new fencing technologies. Here we present a virtual fence based on an electromagnetic coupling principle. The fence is an insulated wire in loop unrolled on the ground around the animals. An electromagnetic field is created in the wire which is coupled to a device carried by collared animals. When the fence signal is detected by the collar, a behavior algorithm decides the action to apply to the animal to prevent it from crossing the wire. More than 800 days of experiment on 150 cattle of different breeds were carried out in France between 1999 and 2003. Bringing more flexibility in fencing, this new system could lead to more precise management of grazing in protected zones and allows for environmental renovation of wild areas.