This visualization provide a holistic picture of the spatial and temporal variation in migration activity during a given period. Each pathline represents the expected travel path of an imaginary swarm of average migrants during the selected observation period. Each pathline corresponds to approx. migrants. The amount of pathlines and their distribution corresponds with the observed densities during the observation period. The pathlines are anchored within a radius of km around the radars. Their length corresponds to the distance covered by the migrants during the selected time window while the varying thickness reflects changes in migrant density during the observation period.