Meeting Abstract

S6.2  Tuesday, Jan. 5  Endocrine and metabolic parameters track daily changes in behavior of a captive migrant RAMENOFSKY, Marilyn*; MOFFAT, John; GUGLIELMO, Christopher; University of California, Davis; University of Washington, Seattle; University of Western Ontario mramenofs@ucdavis.edu

Nocturnal migrants alternate between states of anabolism and catabolism daily. Gambel’s White-crowned Sparrow, Zonotrichia leucophrys gambelii (GWCS), a short-bout, long-distance migrant, follows this pattern with nocturnal flight followed by daytime rest or stop-over for refueling. Previously, we identified daily behaviors in captives relating to activities observed in the field. GWCS held on 18L:6D feed during the day, enter a quiescent period prior to lights out, display migratory restlessness (MR) at night and resume feeding in the morning. Using this diel pattern of behavior, we examined whether physiological parameters alter as rapidly as changes in behavior. Specifically, we hypothesized that anabolic measures elevate in plasma when birds feed during the day but catabolic components predominate with expression of MR. Furthermore, prolonging the night phase of the photocycle, extends MR. Thus, we predicted further elevations of catabolic parameters as an indication of increased fuel demand with extended MR. We found, baseline corticosterone parallels activity, low levels by day when birds feed but elevated with MR. Daytime activities are characterized by anabolic measures of elevated lipid and protein deposition. MR is represented by catabolic metabolism of elevated uric acid and ß-hydroxy-butyrate. Using PCA, the ratio of uric acid to ß-hydroxy-butyrate explained most variation and was significantly greater during the anabolic stage (F=18.9,P< 0.001). Prolonged MR resulted in further elevations of catabolic measures. In support of the hypothesis, results indicate rapidity with which endocrine and metabolic systems react to energetic demands of MR on a daily basis and may serve as a model for energy flow during migratory flight in free-living birds