Figure 1

The spring migration routes of nine common nightingales. The polygons depict 90% kernel density isopleths of non-breeding (blue), stopover (green) and breeding sites (red) of the males from three populations (B = Bulgaria, I = Italy and F = France). Stopover sites composed of more than 50% unsuitable habitat are marked with asterisks. The currently estimated breeding and non-breeding distribution of the nightingale, according to[29], covers the shaded area. The grey-scale of the background indicates the NDVI (white = non-vegetated, black = dense green vegetation) of the first week of the year 2010.