Fig. 4

Changes of the corrected inter-nest distance (inter-nest distance divided by the longest inter-nest distance observed at the nesting area) between the successful nesting attempts at the two preferred nesting areas in the different years. Pond 1–2 boxes are white, Pond 5 boxes are grey. See boxplot description at Fig. 3. Open circles are outlier (more than 3/2 times of the upper or lower quartile)