Do parents listen to their children? : begging does not go unanswered in European starlings (Sturnus vulgaris)

Abstract

Begging by nestling passerines is an important method of communicating to parents their state of hunger. I examined whether experimentally increased nestling begging in a brood can quickly alter parental provisioning rates in European Starlings (Sturnus vulgaris). I predicted that an increased begging level heard by parents during the experimental treatment would result in a significantly higher number of parental provisioning visits compared to the control through a matched pairs design. Twenty nestbox broods were studied to compare the total number of parental provisioning visits during natural (control) and experimentally increased begging conditions. Begging calls of each brood were recorded when nestlings were 13 days old, and the loudest calls from each brood were made into a three-minute loop that ran continuously for one hour during the experimental treatment. On day 14, the total number of provisioning trips made by parents was first determined over a one-hour control watch (natural begging conditions), and then over a one-hour experimental watch (when the begging audio loop playback was projected). As predicted, parents provisioned at a significantly higher rate during the experimental treatment than the control. This finding suggests that European starlings are very sensitive to begging calls made by their offspring, and respond quickly to any changes in begging.