How to feed a little sparrow? Disentangling determinants and consequences of feeder use in the Eurasian tree sparrow Passer montanus (Linnaeus, 1758) using RFID technology

Abstract

There is extensive debate on supplemental bird feeding given the mixed evidence about its effects on avian taxa. In this study, we quantified feeder use in the Eurasian Tree Sparrow (Passer montanus) from a population in Central Spain using radio frequency identification (RFID) with the aim of unravelling its determinants and consequences. We found extensive variation in feeder use, both individually and temporally. Individuals that made use of feeders later spent more time feeding. Feeder use did not explain variation in reproductive success in our population. Our study indicates that inter-individual differences combined with seasonality are the main determinants of feeder use.