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ABSTRACT Biparental care is common in socially monogamous avian species, but both partners may seek extra‐pair copulations (EPCs). The relative costs and benefits of EPCs between the sexes are likely complex, yet the implications of EPCs for parental care behavior have been examined predominantly in males. Not only could females benefit from EPCs, but females would have additional information about the likelihood of extra‐pair young (EPY) in their nest not available to their partners, which likely influences female behavior. We examined how the presence and abundance of EPY in a nest affect parental behavior in a socially monogamous songbird, song sparrows (Melospiza melodia). We predicted that females who mated outside the social pair would invest more in a clutch with a higher probability of EPY. We monitored nest visitation rates by male and female social partners as a proxy for parental investment and quantified extra‐pair paternity in 45 nests. Maternal visitation rates were higher in nests with EPY compared to nests without, while males did not adjust their investment in relation to the presence of EPY. These findings support our prediction that females who participated in EPC would invest more in the resulting offspring.
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Urban resources limit pair coordination over offspring provisioning
Abstract The amount of care parents provide to the offspring is complicated by an evolutionary conflict of interest (‘sexual conflict’) between the two parents. Recent theoretical models suggest that pair coordination of the provisioning may reduce this conflict and increase parent and offspring fitness. Despite empirical studies showing that pair coordination is common in avian species, it remains unclear how environmental and ecological conditions might promote or limit the ability of parents to coordinate care. We compared the level of pair coordination, measured as alternation and synchrony of the nest visits, of house wrensTroglodytes aedonpairs breeding in a rural (10 nests) and a suburban (9 nests) site and investigated how differences in parental behaviours were related to habitat composition, prey abundance and how they ultimately related to reproductive success. We found that parents alternated and synchronized their nest visits more in the rural site compared to the suburban one. The suburban site is characterized by a more fragmented habitat with more coniferous trees and less caterpillar availability. Offspring from the rural site were heavier at fledging than at the suburban site. Taken together, these results suggest that environmental conditions play an important role on the emergence of coordinated parental care and that considering environmental variables is pivotal to assess the fitness consequences of parental strategies.
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- Award ID(s):
- 1738594
- PAR ID:
- 10194847
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 10
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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