Figure 3.

Onset of daily activity influences reproductive success. (a) Treatment of wild great tit males with a melatonin implant delayed their activity onset (data represent individual averages from 2 to 19 days of recording), and (b) melatonin-treated males also suffered a greater cuckoldry risk (higher proportion of extra-pair (EP) young in their nest). Data points represent mean values for individuals, and vertical lines indicate the mean ± s.e.m. for each treatment group. Adapted from [78].