Corticosterone secretion patterns prior to spring and autumn migration differ in free-living barn swallows (Hirundo rustica L.).

Recent studies of long-distance migratory birds show that behavioural and physiological changes associated with predictable or unpredictable challenges during the annual cycle are distinctively regulated by hormones. Corticosterone is the primary energy regulating hormone in birds. Corticosterone levels are elevated during stresses but they are also modulated seasonally according to environmental conditions and life-history demands.

Seasonal variation in the regulation of redox state and some biotransformation enzyme activities in the barn swallow (Hirundo rustica L.).

Little is known of the normal seasonal variation in redox state and biotransformation activities in birds. In long-distance migratory birds, in particular, seasonal changes could be expected to occur because of the demands of migration and reproduction. In this study, we measured several redox parameters in the barn swallow (Hirundo rustica L.

Body condition is associated with adrenocortical response in the barn swallow (Hirundo rustica L.) during early stages of autumn migration.

Migration is an energy-demanding life-history period and also a significant population-limiting factor of long-distance migratory birds. It is important to understand how corticosterone, the main energy regulating hormone in birds, is associated with behavioural and physiological changes during migration. According to the migration modulation hypothesis (MMH), individual birds may express elevated levels of baseline corticosterone to facilitate fuelling, but down-regulate the adrenocortical response in order to protect skeletal muscles from the catabolic effects of the hormone.