Meeting Abstract
Life history trade-offs influence how organisms allocate limited resources, and how an individual resolves these trade-offs can greatly impact fitness. Telomeres (i.e. noncoding strands that protect DNA integrity) shorten in response to senescence and exposure to stressors, and therefore may allow us to predict how animals allocate these limited resources. Most prior work on this topic focuses on how stress influences telomere shortening, with few studies addressing whether an individual’s existing telomere length can be used to predict future trade-off resolutions under challenging conditions. Here, we used wild female tree swallows Tachycineta bicolor to test the hypothesis that telomere length predicts how individuals resolve trade-offs among territory defense, parental care, and self-maintenance. We measured constitutive variation in telomere length and female aggressiveness, as well as maternal provisioning rates after treatment with either saline or lipopolysaccharide (LPS) injection, an immunological stressor that elicits an acute sickness response. Results indicate that the degree to which telomere length predicts trade-offs may depend on an individual’s condition and the severity of the stressor. Furthermore, trade-offs between territory defense and parental care were only found in individuals with longer telomere lengths, a pattern that has implications for age- or stress- related variation in trade-off resolution and how it is shaped by natural selection. Collectively, our results link variation in telomere length with multiple components of vital life history trade-offs, suggesting that telomeres are not only reactive to stressors but they are also predictive of an individual’s response to stressors.
