Rodent assemblage structure reflects socioecological mosaics of counter-urbanization across post-Hurricane Katrina New Orleans

Abstract

Often overshadowed by global trends in urbanization, counter-urbanization is also on the rise worldwide. Left unaddressed, counter-urbanization can result in conditions that imperil human well-being. For example, counter-urbanization is hypothesized to increase the prevalence of ecological hazards like synanthropic pest and pathogen host species by shifting habitat and resource availability. In this study, we addressed this hypothesis by examining whether the abundance or diversity of rodent hosts varies according to the prevalence of abandoned, unmaintained properties across a mosaic of counter-urbanization in post-Hurricane Katrina New Orleans (Louisiana, USA). We also sought to determine whether management of vacant lots can influence the abundance or diversity of rodents across counter-urbanizing landscapes. Analysis of capture data from multi-year trapping efforts across the greater New Orleans area showed that total rodent abundance was highest in residential areas with high levels of vacancy and unmaintained vegetation as well as low household income and low residency. Greater rodent abundance and richness also occurred in areas with features related to infrastructure loss, such as trash and debris, especially in winter. While these results highlight that property abandonment can augment populations of pest and pathogen host species, our findings also indicate that management of abandoned areas can potentially mitigate public health concerns in counter-urbanizing landscapes.