Male tail length and female mate choice in the monogamous swallow Hirundo rustica

Abstract

Male and female swallows benefit from an early start to breeding because it allows the raising of many young and a high proportion of two broods within a single season. Long-tailed males arrived early in spring while female arrival date was independent of their tail length. Male tail length was significantly positively related to success in mate acquisition and negatively to the duration of the pre-mating period and the start of breeding. Arrival date also influenced success in mate acquisition and mating date. Females chose mates using tail length as a cue. Female mate choice was apparently not affected by territory quality. Female swallows could not predict the intensity of mate guarding or the extent of paternal care (feeding intensity of offspring) from male arrival date or male tail length.