Meeting Abstract
P2.89 Friday, Jan. 4 Metabolite, endocrine and behavioral profiles of migratory white-crowned sparrows. RAMENOFSKY, M.**; MOFFAT, J.; JENSEN, J.; GUGLIELMO, C.G.; University of Washington, Seattle; University of Washington, Seattle; University of Washington, Seattle; University of Western Ontario, London mramenof@u.washington.edu
Migrating birds repeatedly alternate between opposing metabolic states of anabolism (feeding and resting), and catabolism (flight). For the short-bout, long-distance migrant, Gambel�s white-crowned sparrow (Zonotrichia leucophrys gambelii) (WCS), these transitions occur daily: nocturnal flight followed by stopover during which birds refuel and rest in preparation for the next bout of nocturnal flight. Previously, we have identified distinct behavioral states in captive birds over a 24 h period. WCS on a 18L:6D photocycle feed during the day, enter a period of complete quiescence prior to lights out, display intense locomotor activity called migratory restlessness during the night, then resume feeding the following morning. As transitions between behavioral states occur rapidly, we investigated whether plasma metabolites and baseline corticosterone (Cort) offer a fuller elaboration of these states and provide an indication of how birds utilize and replenish fuel stores in relation to migratory restlessness. During mid-day glucose, uric acid and triglyceride are elevated as birds feed and no changes occur during quiescent phase. During nocturnal migratory restlessness, glycerol, β-hydroxybutyrate and Cort are increased. The only change observed following two hours of refeeding in the morning is a decrease of Cort. These data suggest that one night of migratory restlessness relies on lipid and protein fuels and their replenishment may take longer than 2 hours of feeding in the morning to regain positive energy balance. Cort is associated with migratory restlessness. These data highlight the importance of refueling throughout the day following one night of migratory flight and emphasize the need for available food en route during migration.
