Small-scale removal of an emergent coastal weed does not affect space use of a territorial bird which uses those weeds

Management of impactful, non-native vegetation - commonly referred to as weeds - is an important component of coastal management, yet information on how their management might affect coastal fauna is limited. A common focus of existing studies is the assessment of species richness or activity before and after weed removal while direct experimental assessments of individual activity ranges are rare. We individually marked singing honeyeaters ( Gavicalis virescens) throughout Cheetham Wetlands, Victoria, Australia, where African boxthorn ( Lycium ferocissimum) invasion was extensive, often represented the tallest vegetation structure within coastal saltmarsh/grassland and was used extensively by singing honeyeaters. Individual birds were repeatedly located to establish range sizes before and after removal of boxthorn. Four sites were considered 'impact' sites, where two boxthorn plants (6.7-33.3 % of plants present) were removed, cut down and branches left in situ to retain some habitat structure. Two sites represented controls, where no boxthorn removal occurred. Honeyeater activity range size did not change in response to weed removal, and range overlap pre- and post-removal was high (80 +/- 23 %, mu +/- SD) - although variation of range size at the individual-level was high. Boxthorn represented the most frequently used perch type both before and after removal, as dead boxthorn was also used for perching. Our results suggest the small-scale, selective, weed management that seeks to retain vegetation structure has negligible immediate impacts on singing honeyeaters inhabiting coastal areas.