Avian responses to an emergent, wetland weed

Abstract

African boxthorn (Lycium ferocissimum Solanaceae) is a Weed of National Significance in Australia. It is particularly problematic in Victoria and is thought to not only threaten native wildlife but also provide important habitat, particularly to birds, when there is no native alternative. In a wetland ecosystem such as a saltmarsh, boxthorn has the potential to increase structural complexity because it can stand as an emergent above surrounding vegetation. We compared bird assemblages and behaviour in saltmarsh vegetation with and without boxthorn in a coastal wetland in south-east Australia. Species assemblage, but not richness, changed with the presence of boxthorn. The presence of singing honeyeaters (Lichenostomus virescens) and white-fronted chats (Epthianura albifrons), the two most common native bird species (based on numerical and spatial dominance), appeared to drive these differences; singing honeyeaters preferred boxthorn while white-fronted chats avoided it. The presence of boxthorn increased the seasonal availability of fruit and flowers, which was reflected by a high frequency of foraging for fruit and nectar where boxthorn was present. In saltmarshes without boxthorn, there was a higher frequency of foraging for insects. Some, but not all, species responded to increased structural complexity and fruit/ floral resources provided by boxthorn. Consequently, management by reducing boxthorn is likely to alter bird communities and the usage of sites by some native species, thus management success should consider fine-scale biodiversity objectives, such as managing for particular types or species of birds.

Maintaining vegetative structure during weed management sustains birds and an invasive mammal

“…This also suggests that weeds were not solely relied on for direct food resources, rather they used boneseed for structural cover and protection. In contrast, some native birds in the Wetland were strongly influenced by weed cover (Carlos et al 2017). The increase in the debris gradient and consistency in shrubby and emergent density gradients in impact sites, confirmed that management was effective in maintaining available vegetation structure following management.…”

“…We investigated the short‐term impacts of small‐scale, perceived wildlife‐friendly weed management—that is herbicide application which kills the weeds but maintains structural complexity conferred by the weeds in the landscape—on birds and small mammals. We monitored faunal communities throughout weed management that retained vegetation structure in two ecosystems, and which have been previously surveyed to understand the impacts of weeds on these species (Wetland: Carlos et al 2017; Woodland: Carlos et al 2023). We predicted that management would result in limited shifts in wildlife species detected supporting the assertion that this management technique is indeed “wildlife friendly”.…”

“…This is true for intensive weed management where effects are likely to be apparent over short timescales. Structural complexity of habitats—including weedy vegetation—has been shown to support comparable species communities to those in uninvaded landscapes (Carlos et al 2017; Ranyard et al 2018; Carlos et al 2023). It is therefore possible that controlling weeds in such a way as to maintain vegetative structure (albeit dead vegetation) may mitigate the impacts of this management on wildlife.…”

On the Construction of Wetland Bird Habitat and Bird Watching Tourism

“…China's wetlands are characterized by a wide range of resources, complete species and many biological resources, which provide good conditions for wetland tourism. The main wetland tourism resources in China can be divided into swamp wetland, Lake wetland, river wetland, shallow water area, beach wetland and artificial wetland [3][4].…”

Invasive African boneseed and a native shrub support similar faunal assemblages in a heavily infested landscape

“…Hence, substantive negative impacts on wildlife populations could manifest during the interval between control and restoration. Despite this, limited research has focused on the ecological importance of invasive plants for wildlife in contexts where weed control is desired (Aslan & Rejmanek, 2010; Carlos et al, 2017; Schlesinger et al, 2020).…”