No short-term change in avian assemblage following removal of Yellow-throated Miner (Manorina flavigula) colonies

Abstract

The overabundance of Yellow-throated Miner (Manorina flavigula) has been shown to negatively affect the abundance and richness of small birds in areas they occupy, leading to homogenization of the avifauna across the fragmented landscape. In this study, we took advantage of a planned management cull to ask the question, does the removal of Yellow-throated Miner colonies cause an immediate change in avian species richness and abundance? This cull was undertaken around the Bronzewing Flora and Fauna Reserve (north-western Victoria, Australia) in order to protect a resident population of endangered Black-eared Miner (M. melanotis) from hybridization. We conducted avian surveys along roadsides surrounding the reserve at Yellow-throated Miner colonies (n = 6), control sites with no miners (n = 7), and where colonies were removed (n = 3). We found that the cull was followed by only a very modest increase in the species richness and abundance of small birds, with no significant effects on avian assemblage overall. This result contrasts with far more dramatic increases following culls of other species of miner. Sites where miners were removed were not depauperate of other species prior to the cull, which could have been due to a combination of proximity to refuge for small birds in a neighbouring reserve or the low numbers of miners that made up each culled colony. This study highlights that assumed effects of a management action may be highly dependent upon spatial and temporal context.