Fig. 3
From: High individual repeatability of the migratory behaviour of a long-distance migratory seabird
Wintering areas of common terns tracked with light-level geolocators for four (a–c, n = 12) or three years (d–f, n = 11). Dots represent an individual’s locations (estimated using FLightR) at daily twilights from one week after the estimated arrival up to one week before the estimated departure from the wintering area. For the birds of which the geolocator stopped working at the wintering area, data for that year were used until the last estimated position. The heatmaps of the twilight positions were produced in QGIS using quartic kernel density with a 2º radius, and visually scaled from 1 (transparent) to 300 (most intense) twilights