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Actuarial Senescence In A Dimorphic Bird: Different Rates Of Ageing In Morphs With Discrete Reproductive Strategies, M. L. Grunst, A. S. Grunst, Vincent A. Formica, M. L. Korody, A. M. Betuel, M. Barcelo-Serra, R. A. Gonser, E. M. Tuttle
Actuarial Senescence In A Dimorphic Bird: Different Rates Of Ageing In Morphs With Discrete Reproductive Strategies, M. L. Grunst, A. S. Grunst, Vincent A. Formica, M. L. Korody, A. M. Betuel, M. Barcelo-Serra, R. A. Gonser, E. M. Tuttle
Biology Faculty Works
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 …
Morph-Specific Patterns Of Reproductive Senescence: Connections To Discrete Reproductive Strategies, A. S. Grunst, M. L. Grunst, Vincent A. Formica, M. L. Korody, A. M. Betuel, M. Barcelo-Serra, S. Ford, R. A. Gonser, E. M. Tuttle
Morph-Specific Patterns Of Reproductive Senescence: Connections To Discrete Reproductive Strategies, A. S. Grunst, M. L. Grunst, Vincent A. Formica, M. L. Korody, A. M. Betuel, M. Barcelo-Serra, S. Ford, R. A. Gonser, E. M. Tuttle
Biology Faculty Works
How reproductive strategies contribute to patterns of senescence in natural populations remains contentious. We studied reproductive senescence in the dimorphic white-throated sparrow, an excellent species for exploring this issue. Within both sexes the morphs use distinct reproductive strategies, and disassortative pairing by morph results in pair types with distinct parental systems. White morph birds are more colorful and aggressive than tan counterparts, and white males compete for extrapair matings, whereas tan males are more parental. Tan males and white females share parental care equally, whereas white males provide little parental support to tan females. We found morph-specific patterns of reproductive …