Figure 1
From: Age-dependent carry-over effects in a long-distance migratory bird
Summary of the full process developed to identify the wintering areas of our barn swallow populations breeding in Denmark. (A–C) Represent δ2H, δ13C and δ15N feather isoscapes73. (D) Represents breeding (red circles) and wintering (blue circles) locations for a given individual breeding between 5°E and 15°E longitude60. (E) Represents the population likely origin of our sample individuals based only on the multivariate assignment of δ2H, δ13C and δ15N. (F) Represents the prior surface obtained from fitting a von Mises probability density function to bearings connecting breeding and wintering locations. (G) Represents the likely origin population of our sample of individuals after incorporating the prior surface into the multivariate assignment of δ2H, δ13C and δ15N. (H) Represents the pixels that were assigned to be the likely origin for >50, >60 and 70% of our sample. These three spatial scales were then used to extract NDVI values. All maps were generated in ArcGis 10.2.2. (https://support.esri.com/es/products/desktop/arcgis-desktop/arcmap/10-2-2), but raster computations were conducted in R65.
