| Popis: |
Previous research on hooting in male scops owls, Otus scops, has shown that heavier males produce overall lower-frequency hoots, and that males alter, and attend to, hoot frequency during territorial contests. We examined how hoot frequency relates to, and possibly affects, male fitness. We quantified the reproductive success of 20 breeding pairs, and documented the phenotypic attributes of both the female and the male, including acoustic variables characterizing male hoots. We investigated whether male body condition, skeletal size and hoot frequency are predictors of the pair's reproductive success. Paired males in good condition did not breed earlier or produce more and heavier fledglings; however, paired males with lower-frequency hoots did breed earlier and produce more and heavier fledglings, even when the effect of interindividual variation in body condition on hoot characteristics was controlled for. Since males with lower-pitch hoots did not have access to better females, we suggest that this relationship might be a product of their increased competitive ability during territorial establishment, where males with lower-pitch hoots acquire better territories, leading to the production of fitter offspring. This also suggests that, in scops owls, males with lower-pitch hoots than expected from their body condition are currently under positive selection from intrasexual competition pressure. |
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