Evaluating the success of wildlife crossing structures using genetic approaches and an experimental design: Lessons from a gliding mammal

Abstract

Millions of dollars are spent on wildlife crossing structures intended to reduce the barrier effects of roads on wildlife. However, we know little about the degree to which these structures facilitate dispersal and gene flow. Our study incorporates two elements that are rarely used in the evaluation of wildlife crossing structures: an experimental design including a before and after comparison, and the use of genetic techniques to demonstrate effects on gene flow at both population and individual levels. We evaluated the effect of wildlife crossing structures (canopy bridges and glider poles) on a gliding mammal, the squirrel glider (Petaurus norfolcensis). We genotyped 399 individuals at ei..