Phenological shifts in amphibian breeding influences offspring size and response to a common wetland contaminant
Author ORCID Identifier
anthropogenic climate change, amphibian, contaminant tolerance, phenology, road salt
Increases in temperature variability associated with climate change has critical implications for the phenology of wildlife across the globe. Indeed, there have been many examples of warmer winter temperatures (i.e. “false springs”) inducing forward shifts in breeding phenology. Earlier breeding can put wildlife at risk of freeze events during reproduction or vulnerable early life stages. Furthermore, in addition to temperature shifts, wildlife populations commonly encounter a wide diversity of other stressors (e.g. pollutants). As global change is predicted to increase both temperature variability and instances of pollutant contamination, understanding interactions between these stressors will become increasingly important. Using 14 populations of a widespread amphibian (wood frog; Rana sylvatica), we evaluated how differences in breeding phenology (early- versus late-breeding cohorts) across two breeding seasons influenced offspring 1) growth; 2) tolerance to a common wetland contaminant (NaCl); and 3) ability to acclimate to NaCl. Offspring of late-breeding cohort were larger and less tolerant of NaCl compared to offspring of the early-breeding cohort. Additionally, while offspring of the early-breeding cohort were able to acclimate to a lethal concentration of NaCl following sublethal exposure by becoming more tolerant to later NaCl exposure, offspring of the late-breeding cohort became less tolerant to NaCl. Interestingly, the negative effects of late breeding phenology on responses to NaCl only occurred during the colder of the two breeding seasons. Collectively, these results suggest that freeze events in the parental environment following false springs may have cascading consequences on offspring mass and ability to tolerate future stressors.
Buss, Nicholas; Swierk, Lindsey; and Hua, Jessica, "Phenological shifts in amphibian breeding influences offspring size and response to a common wetland contaminant" (2020). Biological Sciences Student Scholarship. 4.