Honest Advertisement in Flight Displays of Bobolinks (Dolichonyx oryzivorus)

We studied the flight display of the Bobolink (Dolichonyx oryzivorus) to determine if it functions as a signal of male quality. We tested the hypothesis that flight display is an honest signal of male quality limited by its energetic costs. Male Bobolinks' display durations positively correlated with condition, and with the number of young fledged. To increase variation in display durations, we handicapped some males by wing clipping. Mating success, male condition, and fledging success were used as possible measures of male quality to compare clipped with unclipped birds. Males with clipped wings had shorter display durations and acquired fewer mates. The evidence supports the hypothesis that the Bobolink's flight display could be used as a reliable signal of male quality.