1.Determining global position by lightmeasurements (‘geolocation’) has revolutionised the methods used totrack migratory birds throughout their annual cycle. 2.To date, there is no standard way of analysing geolocator data, making communication of analyses cumber-some and hampering the reproducibility of results. 3.We have, therefore, developed theRpackageGeoLight, which provides basic functions for all steps of deter-mining global positioning and a new approach in analysing movement pattern. 4.Here, we briefly introduce and discuss the major functions of this package using example movement data ofEuropean hoopoe (Upupa epops).