The trade-off between rapid feather growth and impaired feather quality increases risk of predation

Abstract

Feathers are used for flight, and any damage to feathers impairs efficient escape from predators. Because individuals can either rapidly produce feathers of poor quality or slowly produce feathers of high quality, prey experience a trade-off between speed of molt, quality of feathers, and risk of predation. We analyzed feathers produced by Woodpigeon Columba palumbus prey captured by Goshawks Accipiter gentilis and compared those to feathers shed during molt in the same areas. Feathers that were produced rapidly as reflected by long daily growth increments suffered from a greater degree of feather wear than feathers that were produced slowly. Prey had longer daily growth increments and a shorter period of molt than non-prey. Woodpigeons with worn feathers were more likely to fall prey to Goshawks than those with little or no wear to the plumage. These effects were independent of age, year, and time during the breeding season. These findings are consistent with a trade-off between speed of molt and feather quality affecting predation risk.