Variable wind directions and anemotactic strategies of searching for an odour plume

This paper deals with anemotactic strategies of searching for odour plumes under conditions of variation in wind direction and equal energy costs involved in moving a unit path length in any direction in the x, y plane. It is generally accepted that cross-wind searching is the best searching strategy to acquire a maximum amount of information. This is of course true, if the wind is unidirectional. A geometrical model of anemotactic searching is presented that takes into account variation in wind direction. It is shown, that, if wind direction fluctuates over a range larger than 30 degrees from the mean wind direction, then upwind or downwind searching is the best strategy and cross-wind searching is the worst of all possibilities.