Characterizing the baseline and stress-induced hormonal, metabolite, and immune profiles of wild animals is important to assess the impacts of variable environments, including human-induced landscape changes, on organismal health. Additionally, the extent to which these profiles are coordinated across physiological systems within individuals remains an important question in understanding how stressors can differentially affect aspects of an individual's physiology. Here, we present data from wild populations of the common garter snake (Thamnophis sirtalis) on both baseline and stress-induced biomarkers: plasma corticosterone (CURT) concentration, plasma glucose concentration, and whole blood heterophil:Iymphocyte ratio. Using a standardized restraint protocol with individuals from populations in disparate portions of this species' range the Sierra Nevada Mountains of California and the plains of Iowa we collected blood plasma samples at nine time points over three days. Both CURT and glucose response curves differed between georegions, with Iowa snakes attaining higher glucose concentration and maintaining elevated CURT and glucose levels for a longer duration. Additionally, both the total amount and proportional increases of CURT and glucose were lower in larger and therefore older snakes, suggesting ontogenetic shifts in stress perception or response. Within-individual correlation among the three physiological indicators was significant at the time of capture, absent after 3 h in captivity, and partially restored after 3 days in captivity, demonstrating the effect of stress on the relationships among these physiological systems. Together, these results provide further evidence for the great physiological flexibility of ectothermic tetra pods in maintaining homeostasis across a range of factors. (C) 2016 Elsevier Inc All rights reserved.
