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January 3 - Febuary 28, 2021

Meeting Abstract

P15-6  Sat Jan 2  Examining the effects of conventional and organic agriculture on capacity to cope in larval grey treefrogs (Hyla versicolor) Bryant, AR*; Gabor, CR; Texas State University; Texas State University

Conventional agricultural inputs can have a variety of negative effects on physiology and fitness, which contribute to population declines. Organic agriculture is often proposed as a means of increasing sustainability while minimizing negative impacts on wildlife. In amphibians, the physiological response to external perturbations is controlled by the hypothalamus-pituitary-intrarenal (HPI) axis, which regulates the release of the glucocorticoid (GC) hormones. When individuals are repeatedly exposed to stressors throughout their lives, maintaining the capacity to cope with persistent stressors is crucial. If repeated exposure dysregulates the HPI axis, then pathological effects may impact fitness and can lead to death. In such cases, altering the GC profile (both the stress response and recovery) may aid with coping but may come at costs to fitness measures. Studies thus far have not found significant differences between the impacts of organic and conventional inputs on biodiversity or fitness indicators, but no study has examined the endocrine profiles. We hypothesized that the capacity to cope with stressors in larval gray treefrogs (Hyla versicolor) would differ across ponds near conventional, organic, and natural agricultural fields. We used non-invasive water-borne hormones to measure the GC profile of 16 individuals from 3 ponds in each treatment. We predict stronger stress response and quicker recovery in tadpoles from ponds with organic and conventional inputs than natural ponds. These tadpoles may suffer greater fitness costs associated with the agricultural inputs including lower body condition and more parasites.