title: The effect of mercury on baseline corticosterone in a breeding songbird.
abstract: Although songbirds accumulate mercury at rates equivalent to better-studied aquatic avian species, effects of mercury bioaccumulation in songbirds remain understudied. Little is known about the effects of mercury on endocrine physiology, but recent evidence indicates that mercury may disrupt the function of the hypothalamic-pituitary-adrenal axis. Both field-based correlational studies and a recent dosing experiment suggest that mercury exposure alters levels of the primary avian stress hormone, CORT. We sampled zebra finches that had been dosed with 0, 0.5, or 1.0 ppm dietary methylmercury for baseline CORT twice; once during pairing and once after successfully fledging young. Circulating levels of CORT were not significantly affected by mercury exposure. However, our findings indicate potentially important differences in CORT responses between the sexes when exposed to environmentally relevant doses of mercury across the nesting cycle.
authors.affiliation: Department of Biology, College of William and Mary, Williamsburg, VA, 23187, USA.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Maddux
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Cristol
authors.forename: Claire W
authors.initials: CW
authors.lastname: Varian-Ramos
authors.forename: Eric L
authors.initials: EL
authors.lastname: Bradley
mesh_terms: D000818:Animals; D001947:Breeding; D003345:Corticosterone / Q000097:blood*; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D046369:Finches / Q000502:physiology*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D008297:Male; D008628:Mercury / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000633:toxicity*; D010913:Pituitary-Adrenal System / Q000187:drug effects; D012098:Reproduction / Q000187:drug effects
chemical_list: D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D008628:Mercury; D003345:Corticosterone