Meeting Abstract
Climate change is expected to increase temperatures and drought frequency which can combine with direct threats such as urbanization to alter habitat quality such as canopy cover. Together these factors can affect overall health and survival of individuals, disrupting homeostasis, development, and immune responses, which increase the susceptibility of populations to declines. In response to stressors, vertebrates release glucocorticoids (GC) that assist in energy mobilization, mediate natural changes in physiology and behavior, and help return the organism to homeostasis. Amphibians are particularly susceptible to changes in environmental conditions, releasing the GC hormone corticosterone (CORT) in response to stressors, including increased temperatures. Increased temperatures also result in faster metamorphosis, but reduced body size and lower survival. I tested the hypothesis that higher water temperatures affect physiological health in tadpoles. I set up a laboratory experiment manipulating water temperatures using tank heaters (19C vs 27C) and manipulated canopy in outdoor mesocosms with shade cloth or open canopy. To assess physiological health, I examined water-borne CORT release rates, development, and mucosome function of Rio Grande leopard frog (Rana berlandieri) tadpoles. Mucosome function is the ability of the skin secretions and microbiotic community to fight a known pathogen. Increased water temperatures raised CORT release rates in lab-reared tadpoles. Tadpoles developed faster in open canopy but had lower survival, while CORT release rates and mucosome function differed between treatments. This research examines a robust suite of physiological metrics and indicates increased water temperatures from modified habitat and climate change can have multiple negative impacts on developing amphibians.
