Data from: Divergent physiological acclimation responses to warming between two co-occurring salamander species and implications for terrestrial survival

Small differences in physiological responses are known to influence demographic rates such as survival. We tested for differences in the physiological acclimation responses of two closely-related salamander species that often co-occur, Ambystoma maculatum and A. opacum. Specifically, we measured changes in critical thermal maxima (CTmax), standard metabolic rates (SMRs), and respiratory surface area water loss (RSAWL) following exposure to three temperature treatments under laboratory conditions. While the magnitude of RSAWL and CTmax acclimation responses to warming did not differ between the study species, SMR was maintained across acclimation temperatures among A. maculatum, but declined among A. opacum acclimated to warmer temperatures. Metabolic compensation may facilitate maintained A. maculatum activity levels during warm periods following the relatively cool spring breeding season. In contrast, metabolic suppression may allow A. opacum to conserve energy when exposed to surface conditions during fall breeding and nest guarding. We simulated how these different SMR responses would likely alter post-metamorphic survival in our study species using previously collected data representing six weeks under relatively warm seminatural conditions. Our simulation indicated that, following warming and under identical study conditions, metabolic compensation may allow juvenile A. maculatum to maintain survival likelihoods, whereas metabolic depression may cause juvenile A. opacum to experience increased survivorship. These findings underscore that comparable physiological responses among ecologically similar, sympatric species cannot be assumed. Further, results of this study suggest that metabolic responses may play an important role in amphibian species persistence as temperatures increase due to habitat modification and climate change.Available files include: R scripts used to: correct standard metabolic rate and respiratory surface area water loss data for individual body shape and size, and examine whether these corrected measures differed between species or acclimation temperature treatments (RSAWL_SMR_Survivors2017-2018_Jan2022.R) examine whether critical thermal maxima differed between species or following acclimation temperature treatments (CTmax.R) simulate juvenile ambystomatid survival probabilities given the results of acclimation temperature treatments (Simulation_Jan2022.R). All necessary and previously unpublished data files to run these R scripts and support the findings of our study (CTmax-Data.csv, CTmax-Deltas.csv, 2018_Survivors_Means.csv). Scripts were developed and run using R version 4.1.2. 'n/a' indicates samples for which specified data were not collected.Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: DEB-0949357Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: IOS-1051793Please see the associated manuscript for full methodological details