Red Color Bands Reduce Fledging Success in Red-Cockaded Woodpeckers

An analysis of the effects of colored leg bands on Red-cockaded Woodpeckers, in a long-term field study, showed that males that wore red bands fledged significantly fewer young than males without red bands. Other colors were unrelated to fledging success. Band color had no detectable effect on the fledging success of adult females. The offspring sex ratio of breeding males wearing red bands was significantly female-biased. Offspring sex ratios were not related to the presence or absence of red bands on breeding females. Wearing a red band did not affect the probability of a male attracting a mate or the probability of switching mates. For both sexes, annual age-specific survival was independent of the presence or absence of a red band, but nestlings wearing red bands were less likely to be sighted as fledglings. Males with red bands fledged fewer young, consistent with both the species-recognition hypothesis and the coverable-badge hypothesis. The coverable-badge hypothesis, which predicts that the inability to conceal a voluntary social signal (the red cockade) can be detrimental, is the more parsimonious explanation of our results.