Seasonal changes in adrenocortical responses to acute stress in polygynous male bush warblers (Cettia diphone)

摘要: The adrenocortical response to acute stress as measured by increase in plasma levels of corticosterone following capture, handling, and restraint over an hour was estimated free-living male bush warblers at different times the breeding season on their ground Chichibu, Honshu, Japan. Initial showed a seasonal change, being moderate April, highest May July declined late August. In contrast, suppressed early stage season, April May, just after June, July, August, obvious although initial were high. These results are from those monogamous passerine birds so far studied which is later when involved parental care. suggest that during course take polygynous strategy may decrease amplitude allow establishment defense territory. became more sensitive they already had females incubating, feeding hatchlings or even fledging. This change likely be reflection species.