Diurnal and Nocturnal Patterns of Activity in Resident and Migrant Silvereyes Zosterops lateralis

Abstract

This study examined diurnal and nocturnal activity patterns from 40 hours of continuous activity recordings of individually caged resident and migrant Silvereyes Zosterops lateralis. Elevated night activity (= Zugunruhe) was displayed by migrants in autumn and spring but not by residents. Zugunruhe commonly commenced in the dark portion of the morning and continued to about 2-3 h beyond the onset of light. Migrants were more night restless than residents in winter and in the migratory seasons of autumn and spring. They were also more diurnally active in the winter months than residents. The increase in diurnal activity in the latter period is related to winter migratory movements.