Males are generally predicted to care less for their young when they have more additional mating opportunities, lower paternity, or when their mates care more. We tested these predictions using male provisioning as a proxy for paternal care in two temperate populations of house wrens (Troglodytes aedon) with divergent life histories. Males in the migratory, occasionally socially polygynous New York, USA (northern) population provisioned less when more local females were fertile. A similar relationship was only weakly supported in the resident, socially monogamous Buenos Aires Province, Argentina (southern) population, possibly due to the higher density of house wrens there. A relationship between male provisioning and level of paternity within the brood was supported in both populations, but in opposite directions: while males in the southern population provisioned less at broods containing more extra-pair young, males in the northern population provisioned such broods more, contradicting predictions. Males provisioned less when their mates provisioned more in both populations, in agreement with sexual conflict theory. Additionally, the populations both exhibited a positive relationship between male provisioning and nestling age, but differed in the direction of the relationships of male provisioning with date and brood size. Our results suggest that even within a species, life history differences may be accompanied by differences in the determinants of behavior such as paternal care.
Bibliographical noteFunding Information:
Acknowledgments This study was funded by the Fuller Evolutionary Biology Program at the Cornell Lab of Ornithology (KL), a Howard Hughes Summer Scholarship (KL), a National Science Foundation Graduate Research Fellowship (KL), a Mario Einaudi Center International Research Travel Grant (PEL), an Organization of American States Graduate Fellowship (PEL), the Scientific Research Society (PEL), an American Ornithologists’ Union Research Grant (PEL), and an Andrew W. Mellon Student Research Grant (PEL). G. Fernández, M. Mermoz, V. Ferretti, and P. Rodriguez provided field assistance, the Whisky-Michelli family generously allowed us to work on their ranches, and M. Beade provided logistical support. L. Stenzler, E.R.A. Cramer, A. Talaba, D. Morin, C. Makarewich, and B. Winger provided laboratory assistance and advice. J.P. Kelley and C. Tarwater lent statistical advice. I. Stewart, two anonymous reviewers, and the lab groups of E.A. Lacey, R. Bowie, R. Caldwell, and D. Elias made valuable comments on earlier versions.
- Extra-pair paternity
- House wren
- Parental care
- Sexual conflict
- Troglodytes aedon