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Summary Host‐associated microbiomes play an essential role in the health of organisms, including immune system activation, metabolism and energy uptake. It is well established that microbial communities differ depending on the life stage and natural history of the organism. However, the effects of life stage and natural history on microbial communities may also be influenced by human activities. We investigated the effects of amphibian life stage (terrestrial eft vs. aquatic adult) and proximity to roadways on newt skin bacterial communities. We found that the eft and adult life stages differed in bacterial community composition; however, the effects of roads on community composition were more evident in the terrestrial eft stage compared to the aquatic adult stage. Terrestrial efts sampled close to roads possessed richer communities than those living further away from the influence of roads. When accounting for amplicon sequence variants with predicted antifungal capabilities, in the adult life stage, we observed a decrease in anti‐fungal bacteria with distance to roads. In contrast, in the eft stage, we found an increase in anti‐fungal bacteria with distance to roads. Our results highlight the need to consider the effects of human activities when evaluating how host‐associated microbiomes differ across life stages of wildlife. 

Abstract Glucocorticoids (corticosterone/cortisol; cort) are frequently used in conservation as biomarkers of disturbance in wild populations. However, the context‐dependent nature of cort means that it may not always accurately reflect disturbance. For example, there is growing evidence that wildlife populations can evolve or acclimate to human‐induced environmental change (i.e. contaminants) by expressing higher levels of tolerance. Mechanisms that allow for populations to achieve higher contaminant tolerance can be related to cort and thereby impact the reliability of cort as an indicator of disturbance. This study asks: (1) do wildlife populations that differ in tolerance to contaminants differentially express baseline and stress‐induced cort and (2) is cort a viable indicator of disturbance across populations that differ in tolerance to contaminants? Toward this goal, we identified three wood frogRana sylvaticapopulations with relatively high NaCl tolerance and three populations with relatively low NaCl tolerance. Tadpoles from these populations were reared to metamorphosis in either an environmentally relevant concentration of NaCl (0.5 g L⁻¹NaCl) or a control (0 g L⁻¹NaCl). At metamorphosis we used a non‐invasive waterborne assay to measure baseline and stress‐induced cort release rates and measured fitness‐related metrics. We found that contaminant tolerance influences cort levels. More tolerant populations had lower baseline cort and higher fitness compared to less tolerant populations. However, despite variation in cort across populations with different levels of tolerance, cort still represents a viable indicator of condition as our results show a consistent negative relationship between cort and fitness. Lastly, we found that levels of cort were consistent regardless of whether amphibians were reared in NaCl contaminated or non‐contaminated environments. Overall, we emphasize the importance of recognizing population‐level variation in cort due to contaminant tolerance when using cort as a biomarker for conservation purposes. 

Abstract In a rapidly changing world, phenotypic plasticity may be a critical mechanism allowing populations to rapidly acclimate when faced with novel anthropogenic stressors. Theory predicts that if exposure to anthropogenic stress is heterogeneous, plasticity should be maintained as it allows organisms to avoid unnecessary expression of costly traits (i.e., phenotypic costs) when stressors are absent. Conversely, if exposure to stressors becomes constant, costs or limits of plasticity may lead to evolutionary trait canalization (i.e., genetic assimilation). While these concepts are well‐established in theory, few studies have examined whether these factors explain patterns of plasticity in natural populations facing anthropogenic stress. Using wild populations of wood frogs that vary in plasticity in tolerance to pesticides, the goal of this study was to evaluate the environmental conditions under which plasticity is expected to be advantageous or detrimental. We found that when pesticides were absent, more plastic populations exhibited lower pesticide tolerance and were more fit than less plastic populations, likely avoiding the cost of expressing high tolerance when it was not necessary. Contrary to our predictions, when pesticides were present, more plastic populations were as fit as less plastic populations, showing no signs of costs or limits of plasticity. Amidst unprecedented global change, understanding the factors shaping the evolution of plasticity will become increasingly important. 

<ext-link href='http://Abstract'>Abstract</ext-link> Global climate change is expected to both increase average temperatures as well as temperature variability.Increased average temperatures have led to earlier breeding in many spring‐breeding organisms. However, individuals breeding earlier will also face increased temperature fluctuations, including exposure to potentially harmful cold‐temperature regimes during early developmental stages.Using a model spring‐breeding amphibian, we investigated how embryonic exposure to different cold‐temperature regimes (control, cold‐pulse, and cold‐press) affected (a) compensatory larval development and growth, (b) larval susceptibility to a common contaminant, and (c) larval susceptibility to parasites.We found: (a) no evidence of compensatory development or growth, (b) larvae exposed to the cold‐press treatment were more susceptible to NaCl at 4‐days post‐hatching but recovered by 17‐days post‐hatching, and (c) larvae exposed to both cold treatments were less susceptible to parasites.These results demonstrate that variation in cold‐temperature regimes can lead to unique direct and indirect effects on larval growth, development, and response to stressors. This underscores the importance of considering cold‐temperature variability and not just increased average temperatures when examining the impacts of climate disruption. 

Art is a common approach for communicating and educating about science, yet it remains unclear the extent to which science art can benefit varied audiences in varied contexts. To examine this gap, we developed an art exhibit based on the findings of two publications in disease ecology. In study 1, we asked visitors with varying formal science, technology, engineering, and math (STEM) education backgrounds to complete a survey about their interest in science research before and after viewing the exhibit. In study 2, we recruited upper-level ecology undergraduate students to receive one of three treatments: engage with the art exhibit, read the abstracts of the papers, or do neither. Students completed a comprehension quiz immediately after their learning treatment and again 2 weeks later to evaluate retention. Following the exhibit, visitors who did not report a career or major in STEM showed a greater increase in research interest than visitors who did report a career or major in STEM. For the ecology undergraduate students, comprehension quiz scores were higher for students in the abstract group than the art exhibit group, while both groups scored higher than the control group. Retention of information did not significantly differ between the three groups. Overall, these findings suggest that science art exhibits are an effective method for increasing the accessibility of science to broader audiences and that audience identifiers (e.g., level of formal education in STEM) play an important role in audience experience of science communication and science education initiatives. 

Abstract Background Increases in temperature variability associated with climate change have critical implications for the phenology of wildlife across the globe. For example, warmer winter temperatures can induce forward shifts in breeding phenology across taxa (“false springs”), which can put organisms at risk of freezing conditions during reproduction or vulnerable early life stages. As human activities continue to encroach on natural ecosystems, it is also important to consider how breeding phenology interacts with other anthropogenic stressors (e.g., pollutants). Using 14 populations of a widespread amphibian (wood frog; Rana sylvatica ), we compared 1) growth; 2) tolerance to a common wetland contaminant (NaCl); and 3) the ability of tadpoles to acclimate to lethal NaCl exposure following sublethal exposure earlier in life. We evaluated these metrics across two breeding seasons (2018 and 2019) and across populations of tadpoles whose parents differed in breeding phenology (earlier- versus later-breeding cohorts). In both years, the earlier-breeding cohorts completed breeding activity prior to a winter storm and later-breeding cohorts completed breeding activities after a winter storm. The freezing conditions that later-breeding cohorts were exposed to in 2018 were more severe in both magnitude and duration than those in 2019. Results In 2018, offspring of the later-breeding cohort were larger but less tolerant of NaCl compared to offspring of the earlier-breeding cohort. The offspring of the earlier-breeding cohort additionally were able to acclimate to a lethal concentration of NaCl following sublethal exposure earlier in life, while the later-breeding cohort became less tolerant of NaCl following acclimation. Interestingly, in 2019, the warmer of the two breeding seasons, we did not detect the negative effects of later breeding phenology on responses to NaCl. Conclusions These results suggest that phenological shifts that expose breeding amphibians to freezing conditions can have cascading consequences on offspring mass and ability to tolerate future stressors but likely depends on the severity of the freeze event.