Woodland birds benefit from suppression of a despotic competitor following creation of artificial ‘sink’ habitat through culling

Abstract

AbstractContext While habitat fragmentation negatively impacts native biodiversity, this ecological process can be beneficial for edge-specialist species that preferentially occupy remnant patches. In the eastern woodlands of Australia, this process leads to the despotic Noisy Miner (Manorina melanocephala) dominating remnant patches and aggressively excluding other avifauna. Culling has been trialled in attempt to alleviate the impacts of Noisy Miners, however has yielded mixed success in the short-term as recolonising miners from the surrounding areas rapidly occupy newly culled sites. Objectives We tested if ongoing, continuous removal of Noisy Miners from one site could create an artificial ‘sink’ habitat that would allow more efficient management of recolonisation reduction and allow native woodland bird recovery in other areas. Methods Over 18 months, Noisy Miners were removed from two sites on a regular basis and the changes in the miner density and avian diversity were assessed. Results At one site, birds routinely recolonised newly created vacant ‘sink’ areas following a culling round, therfore miner density at this site was not impacted long-term. In contrast, a nearby area was not effectively recolonised and was kept miner-free for more than one year, concurrently experiencing a rebound in avian diversity. Conclusions Together, these results suggest that as well as being more feasible logistically, conducting ongoing longer-term culling at highly favoured sites is likely to be a more effective and logistically simpler management strategy than repeated, separate short-term culling events at a range of habitats, offering an additional model for the management of overabundant, despotic species.