Long incubation off-bouts of females paired with colorful males in Barn Swallows (Hirundo rustica)

Abstract

ABSTRACT Among several types of parental care behavior, incubation behavior in passerine birds offers an ideal opportunity to study the link between female parental care and male ornamentation, because males generally lack an incubation patch, and thus rarely incubate. Although preceding studies have focused mainly on on-bout duration (or its total amount, i.e., nest attentiveness), it has recently been established that off-bout durations, independent of on-bout durations, are also important for embryo development and thus for efficient incubation. Using Barn Swallows Hirundo rustica, we found that the duration of female incubation off-bouts increased with a sexually selected trait, male throat coloration, independent of female nest attentiveness. A longer female off-bout was positively correlated with the incubation period, indicating that colorful males had reproductive disadvantage because of their mates’ inefficient incubation. Together with a previous study in which females demonstrated a higher amou...