Figure 1. Map showing the centroid coordinates of each Ortolan Bunting singing group (black circles) which had been visited in at least one pair of consecutive years between 2000 and 2018, so that at least one male territory was observed (n = 238) in the first of those surveys. Singing groups were classified into seven major regions indicated with black line. Discarded singing groups (n = 41), not fulfilling these criteria, are indicated by triangles.