Developmental stress and telomere dynamics in a genetically polymorphic species

A central objective of evolutionary biology is understanding variation in life-history trajectories and aging rate, or senescence. Senescence can be affected by tradeoffs and behavioral strategies in adults, but may also be affected by developmental stress. Developmental stress can accelerate telomere degradation, with long-term longevity and fitness consequences. Little is known regarding whether variation in developmental stress and telomere dynamics contribute to patterns of senescence during adulthood. We investigated this question in the dimorphic white-throated sparrow (Zonotrichia albicollis), a species in which adults of the two morphs exhibit established differences in behavioral strategy and patterns of senescence, and also evaluated the relationship between oxidative stress and telomere length. Tan morph females, which exhibit high levels of unassisted parental care, display faster reproductive senescence than white females, and faster actuarial senescence than all of th...