Species’ traits as predictors of avoidance towards roads and traffic

Abstract

Road-networks and their associated motorized traffic pose a threat to biodiversity and ecosystems, with different groups of species exhibiting different avoidance responses. The often species-specific nature of these behavioural responses to roads and traffic suggest that morphological, ecological, life-history and behavioural traits could be useful in explaining and predicting these responses. Trait-based predictive models have been used to assess extinction risk, land use impacts, and road mortality. Here we present the first, to our knowledge, test of their potential to address animal road avoidance. We studied the fleeing responses and spatial distribution in relation to roads of diverse ungulate species across three South African protected areas. Our results show that smaller, solitary species with non-grazing food habits are more likely to flee in response to presence of a vehicle. None of the tested traits showed a clear relationship based on biological hypotheses with initial distance to roads and tolerance distance to vehicles (used to describe behavioural avoidance towards roads and vehicles, respectively). However, we found significant effects that supported proposed methodological hypotheses. Our results show the potential to use traits as indicators of vehicle and traffic avoidance. Obtaining behavioural avoidance data in the field for many species and areas can be time consuming, but here we show it may be possible to use available trait data to generally predict species responses. This could be useful for initial species risk assessments.