Meeting Abstract
Wild birds are used extensively to study the effects of acute stress on the hypothalamic-pituitary-adrenal axis. By contrast, we know little in these birds about the effects of acute stress on other endocrine systems and metabolism, and even less about the persistence of these effects and their behavioral consequences once subjects are returned to their habitat. We caught adult male Rufous-winged Sparrows, Peucaea carpalis, bled them within two minutes (Initial) and again after 30 min of restraint (Stress), released them on site, and re-captured and re-sampled them the next day. Acute stress significantly elevated plasma corticosterone (CORT; 313%) and significantly decreased plasma testosterone (T; 51%), uric acid (UA; 37%), and glucose (GLU; 7%). One day later, plasma CORT and UA had returned to Initial levels but plasma T remained decreased, and plasma GLU was 30% above Initial level. Thus, a brief stressful event had persistent endocrine and metabolic consequences for blood parameters. The stress-associated decrease (within 30 min) followed with increase (next day) in plasma GLU may reflect its rapid utilization followed with CORT-mediated increase of production and secretion. The stress-related decrease in plasma UA was negatively correlated to the corresponding increase in plasma CORT, suggesting an inhibitory effect of CORT on plasma UA. The aggressive response to conspecific song playback did not differ before first capture and before re-capture, suggesting no close temporal relationship between plasma T and the expression of aggressive behavior. In sum, a brief stressful event elicits marked endocrine and metabolic changes, some of which (CORT, UA) are labile whereas others (T, GLU) persist for at least one day after release. Supported by NSF Award 1026620 (P.D.)
