In various embodiments, a method of controlling a position of an animal includes tracking a position of the animal using a positioning system, such as a global positioning system. A time-varying position of a base object is also tracked using the positioning system, and a relative position of the animal with respect to the base object is determined, based on the positions of the animal and the base object. When the relative position exceeds a minimum value, a stimulus is provided to the animal to encourage the animal to reduce the relative position. A user of the system may define a region for the animal using a map of the surrounding territory.