Meeting Abstract
P1.76 Thursday, Jan. 3 Using Fecal Cortisol Assays To Assess Stress in an Endangered Bat RICHARDSON, C.S.*; WIDMAIER, E.P.; HOHMANN, M.; KUNZ, T.H.; Boston Unversity, Massachusetts; Boston Unversity, Massachusetts; U.S. Army Construction Engineering Research Laboratory, Champaign, Illinois; Boston Unversity, Massachusetts crichard@bu.edu
Chronic stress in mammals is associated with elevated daily secretion of glucocorticoids. In bats, the major glucocorticoid is cortisol. Cortisol is a critical hormone that affects most organ systems and physiological processes. However, chronically elevated cortisol leads to immuno-suppression with increased incidence of metabolic disturbances, cardiovascular changes, and infertility. Certain stimuli (“stressors”) appear to be ubiquitously stressful in mammals. These include stimuli such as audible noise and seismic vibration, which are commonly encountered near military bases. We are investigating the long-term consequences of chronic exposure of endangered Indiana bats (Myotis sodalis) to activities associated with training and operations at nearby military bases. Fecal assays have been developed as an indirect means of assessing stress in free-ranging or endangered mammals, without the need for invasive procedures or blood sampling. While most of the circulating glucocorticoids in mammals are excreted in the urine, a small percentage of cortisol appears in the feces in proportion to plasma concentrations. As part of developing and validating this assay for M. sodalis, we collected fecal samples from an abundant, related (non-endangered) species, the little brown myotis (Myotis lucifugus), which serves as a surrogate species. We have optimized the procedure for extracting immunoreactive (ir) cortisol from fecal pellets of M. lucifugus and have demonstrated the presence of ir-cortisol in feces from M. sodalis. We have physiologically validated the fecal cortisol assay for M. lucifugus by demonstrating that an increase in plasma cortisol levels due to handling/blood-sampling stress is followed by an increase in fecal cortisol levels.
