Fig. 3

Age structure calculated based on the wing conditions of B. pales. Days with less than five data were excluded (no analysed data prior to 10 July); black trend line for weighted mean value of the total population (fourth-degree polynomic function); coloured linear trend lines for the three phases of the aging process (yellow: 10 July–03 August, green: 03 August–25 August, orange: 25 August–02 September). Only data of wing decay from the first to the second capture event of each individual were used for the calculations