Ardea Official journal of the Netherlands Ornithologists' Union |
Pagani-Núñez E. & Senar J.C. (2016) More ornamented Great Tit Parus major fathers start feeding their offspring earlier. ARDEA 104 (2): 167-176 |
Carotenoid-based ornaments have been proposed to signal the ability to find food. The good-parent hypothesis suggests that females may rely on these carotenoid-based traits to assess male parental quality. A key question is whether the quality of these ornaments correlates with their performance at the moment of breeding. In this study, we assessed the parental investment of Mediterranean Great Tits Parus major in the early morning as a function of several environmental factors and of parental ornamentation. We measured this by the time that parents started feeding their offspring at the start of the day. In the morning, parents need to rapidly respond to the food demands of their offspring, after a long night without food. An earlier start of provisioning could indicate higher parental investment (and/or greater foraging ability). Our data indicate that fathers that show higher hue in their carotenoid-based plumage – more greenish individuals – started feeding their offspring earlier, thereby expanding the time window in which they work, while females did not show a significant relationship between the onset of provisioning and ornamentation. Parents, particularly mothers, that started earlier, worked more intensely across the whole observation period. Furthermore, parents started earlier when they had larger broods. Finally, more ornamented parents worked at lower rates, while more ornamented mothers raised offspring that had better body condition, which is in line with the good parent hypothesis. Although our results indicate that more ornamented males start feeding their offspring earlier, overall we found mixed support for the hypothesis that carotenoid-based ornaments signal the parental quality of a mate. |