NAVARA, K.J.*; HILL, G.E.; MENDON�A, M.T.; Auburn University, AL; Auburn University, AL; Auburn University, AL: Differential effects of exogenous yolk testosterone on growth and immune response in bluebird nestlings Steroid hormones, such as testosterone (T) and dihydrotestosterone (DHT), deposited into the yolk by female birds and reptiles have been found to have a m�lange of […]

SMALL, Thomas W *; DEVICHE, Pierre; SHARP, Peter; Arizona State University; Arizona State University; Roslin Inst., Scotland: Conspecific and Heterospecific Song Exposure Accelerates Photoinduced Reproductive Development in the Flexibly Breeding Rufous-winged Sparrow, Aimophila carpalis In most birds, annual changes in day length control seasonal reproductive development and regression. For example, photostimulation induces testicular development in […]

BUCK, CLB; O’REILLY, KM; Univ. of Alaska Fairbanks; Univ. of Portland: Brood Size Affects Adrenal Responsiveness of Free-living Kittiwake Chicks Secretion of corticosterone by black-legged kittiwakes (Rissa tridactyla, BLKI) is linked to nutritional state; and sibling aggression, and brood reduction of BLKI are linked to low forage availability. Therefore, we hypothesized that breeding success of […]

SPERRY, TS; WINGFIELD, JC; Univ of Washington; Univ of Washington: Serotonergic Regulation of Glucocorticoid Release in Male White-Crowned Sparrows To maximize fitness, free-living animals modulate their stress response in anticipation of predictable conditions and to cope with unpredictable, environmental perturbations. Modulation of the hypothalamic-pituitary-adrenal axis (HPA) can occur at multiple levels with two principle endpoints […]

WADA, H.*; HAHN, T.P.; BREUNER, C.W.; University of Texas at Austin; University of California, Davis; University of Texas at Austin: Ontogeny of the stress response: comparison of two subspecies of white-crowned sparrow nestlings Elevation of corticosterone (CORT) in response to stress is known to increase survival in adults by redirecting behavior and physiology. However, the […]

HAYWARD, L.S.; WINGFIELD, J.C.; Univ. of Washington, Seattle; Univ. of Washington, Seattle: Maternal Corticosterone Slows Chick Growth and Increases Adult Stress Response In all vertebrates levels of circulating gluccocorticoids rise in response to perturbations ranging from food shortage to encounters with predators to infection. We experimentally elevated the primary avian gluccocorticoid, corticosterone, in laying Japanese […]

BELDEN, L.K.*; RUBBO, M.J.; L�PEZ, M.; RAFFEL, T.R.; MIRZA, R.S.; KIESECKER, J.M.; Virginia Polytechnic Institute and State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; Pennsylvania State University; ; : Effects of Aeromonas hydrophila exposure on wood frog tadpoles and juveniles Like all organisms, amphibians are host to a wide […]

KAHN, P.F.*; GUYER, C.; MENDON�A, M.T.; Auburn University; Auburn University; Auburn University: Differences in Stress Responsiveness and Immunocompetence in Gopher Tortoises With and Without Symptomatic Upper Respiratory Tract Disease The gopher tortoise of the southeastern United States has become a threatened species primarily due to habitat infringement. In recent years, however, the tortoises have faced […]

BOORSE, GC; DENVER, RJ; University of Michican, Ann Arbor: A functional corticotropin-releasing hormone signaling system in Xenopus tadpole tail Corticotropin-releasing hormone (CRH) is the principal neurohormone regulating the hypothalamo-pituitary-adrenal axis. However, the distribution and actions of CRH are not limited to the neuroendocrine system. In mammals and frogs several peripheral tissues are known to express […]

TIELEMAN, B.I. *; WILLIAMS, J.B.; VISSER, G.H.; University of Groningen, The Netherlands; Ohio State University, Columbus; University of Groningen, The Netherlands: The physiology-life history nexus in larks along an aridity gradient We compared physiological, demographic and ecological variables of larks to gain insights into life history variation along an aridity gradient. Quantifying field metabolic rate […]