Meeting Abstract

P3.105  Monday, Jan. 6 15:30  Evaluating the stress response of wild birds as a bioindicator of sub-lethal effects of crude oil exposure LATTIN, CR*; NGAI, H; ROMERO, LM; Tufts University; Tufts University ; Tufts University christine.lattin@tufts.edu

The hypothalamus-pituitary-adrenal (HPA) axis allows wild animals to regulate baseline physiology and respond to environmental stressors. However, there is some evidence that the HPA axis may be especially vulnerable to endocrine-disrupting chemicals. This study aimed to systematically quantify the effects of ingested Gulf of Mexico crude oil on the stress response and blood chemistry parameters of wild-caught house sparrows (Passer domesticus). Crude oil was weathered to ~75% volume by heating at a low temperature and stirring continuously. Oil birds received a dose of 1% oil weight:food weight, determined using preliminary dose-response feeding experiments. Controls received sunflower oil instead of petroleum, and both groups were allowed to feed ad libitum. After 4 weeks, birds on the oiled diet showed reduced stress-induced CORT titers in response to a standardized stressor, as well as decreased CORT secretion after an injection of adrenocorticotropic hormone. They also had increased plasma concentrations of phosphorus and Na+, potentially indicative of disruptions in fluid balance. All of these effects could be due to adrenal and/or kidney damage. A reduction in stress-induced CORT titers after ingesting oil has also been seen in ducks, suggesting this particular effect may occur across many avian species. These effects are important not only as potential bioindicators of petroleum exposure, but because birds with impaired HPA function show higher mortality when faced with stressors.