Roads increase population growth rates of a native leaf-cutter ant in Neotropical savannahs

A challenge in applied ecology is understanding the responses of native species to roads, which are ubiquitous drivers of environmental heterogeneity. While most studies highlight their negative effects, the potential for native species to increase in abundance near roads has been underappreciated, and the demographic mechanisms underlying abundance changes remain unclear. Elucidating these mechanisms requires first determining how demographic vital rates and life-history stages interact to influence population growth. One can then assess how roads alter the relative importance of the alternative demographic pathways – increased performance of early vs. late life stages – suggested as the principal drivers of increased population growth. We parameterized demographic models with 3 years of census data and conducted perturbation analyses to evaluate how proximity to roads altered abundance and demography. To do so, we used the leaf-cutter ant Atta laevigata as our model organism. Leaf-cut...