Seasonal changes in genetic composition and sexual ornamentation in the breeding population. (a) Average pairwise relatedness of arriving females (filled circles, solid line) and males (filled triangles, dashed line) in relation to individuals of the same sex that were present in the population at the time of arrival (females: n=30, males: n=155). (b) Average pairwise relatedness of local resident, early-arriving non-local and late-arriving non-local males (filled bars) and females (open bars) in relation to unpaired mates in the population at the time of arrival. (c) Variation in sexual ornamentation of local males, early-arriving non-local and late-arriving non-local males (10 years, shown is the mean of coefficient of variation for each year+s.e.m). Numbers above the bars indicate the sample sizes.