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Data from: Actuarial senescence in a dimorphic bird: different rates of aging in morphs with discrete reproductive strategies

Citation

Grunst, Melissa L. et al. (2018), Data from: Actuarial senescence in a dimorphic bird: different rates of aging in morphs with discrete reproductive strategies, Dryad, Dataset, https://doi.org/10.5061/dryad.bq8n45v

Abstract

It is often hypothesized that intra-sexual competition accelerates actuarial senescence, or the increase in mortality rates with age. However, an alternative hypothesis is that parental investment is more important to determining senescence rates. We used a unique model system, the white-throated sparrow (Zonotrichia albicollis), to study variation in actuarial senescence. In this species, genetically-determined morphs display discrete mating strategies and disassortative pairing, providing an excellent opportunity to test the predictions of the above hypotheses. Compared to tan-striped males, white-striped males are more polygynous and aggressive, and less parental. Tan-striped females receive less parental support, and invest more into parental care than white-striped females, which are also more aggressive. Thus, higher senescence rates in males and white-striped birds would support the intra-sexual competition hypothesis, whereas higher senescence rates in females and tan-striped birds would support the parental investment hypothesis. White-striped males showed the lowest rate of actuarial senescence. Tan-striped females had the highest senescence rate, and tan-striped males and white-striped females showed intermediate, relatively equal rates. Thus, results were inconsistent with sexual selection and competitive strategies increasing senescence rates. Rather, results suggest that senescence may be accelerated by female-biased parental care, and lessened by sharing of parental duties.

Usage Notes

Location

Eastern North America