The Social and Ecological Benefits of Community-led Backyard Pest Control in Urban Auckland

Abstract

Conservation volunteering by community groups has increased in popularity globally, and managing invasive species, such as mammalian pests, is a key activity for many conservation groups. However, there is a lack of research on the outcomes of community-led pest control for native species in urban areas. Additionally, the benefits and barriers to participation in urban community conservation activities have received little attention. Using Auckland, New Zealand, as a case study, I investigated how participating in community conservation benefits volunteers, and what are the outcomes of community conservation for birds. First, I interviewed leaders of community conservation groups. Interviewees talked about their groups’ social activities and the advantages and disadvantages of working in a group. These interviews helped to shape a subsequent questionnaire, which surveyed members of the wider Auckland public, including members of community conservation groups. I asked people about their environmental attitudes, motivations and barriers to participating in conservation, and social capital; the connections among people and the associated collective positive benefits. I found that conservation leaders often started their groups with a biodiversity motivation, whereas many volunteers joined and continued to participate for social reasons. Members of community conservation groups had higher social capital than people who did not participate in community conservation groups. Therefore, linking social capital benefits to participation in conservation activities could increase conservation’s appeal to people more strongly motivated by personal well-being and a sense of community. Community conservation group members were also more likely to support pest control and had more positive environmental attitudes than non-members. I found that regardless of group membership, people tended to control pest mammals, such as rats, for self-interested reasons, such as preventing property damage, whilst biodiversity motivations were secondary. The primary barrier for people not participating in pest control was a lack of interest in participating. Given the range of motivations and barriers to participation, targeted messaging could increase participation in conservation, as biodiversity motivations alone are unlikely to motivate everyone. To investigate the effect of backyard pest control (trapping and poisoning) on urban birds, I surveyed birds in residential backyards in neighbourhoods with different intensities of pest control. I independently determined the relative abundance of rats (Norway rat Rattus norvegicus; ship rat R. rattus) and modelled detection probabilities and occupancy. Using five-minute bird counts, I compared bird abundance, species richness and community composition between 32 backyards. I recorded 140 nesting attempts from 15 species. Despite pest control, rats were detected at some point in all backyards, but relative abundance was low. Overall, fledging success was high, and predation by pest mammals was relatively low. Daily nest survival rate increased when rat detection rates decreased. The frequency of servicing pest control devices within a backyard was associated with increased fledging success and increased native bird species richness and abundance. This suggests that regular backyard pest control may improve local ecological outcomes for birds in and close to these backyards. High levels of participation in backyard pest control are required to improve outcomes for birds at the neighbourhood level.