Data from: Highway widening and underpass effects on vertebrate road mortality

Road widening (a.k.a. road dualling) and the presence of mitigation structures may have opposing effects on the number of animal-vehicle collisions. Their influence in tropical areas is poorly quantified, and we know little about how modifications of road structure affect fauna roadkill and mitigation. We evaluated how road widening and proximity to a wildlife underpass affect roadkill of medium and large mammals, using roadkill records from before and after the widening of 150 km of road with new and old wildlife underpasses. Roadkilled species were divided into three groups based on mobility and sensitivity to human disturbance. Four out of 16 species exhibited significantly higher roadkill after widening. Roadkill near underpasses was generally higher than by chance, despite our expectation of reduction of roadkills. This result indicates that we must adopt more effective mitigation measures, such as appropriate fencing combined with underpasses.

道路拓宽（亦称道路复线化，road dualling）与野生动物减缓设施的设置，可能会对动物-车辆碰撞事故的数量产生截然相反的影响。目前针对热带区域的此类影响量化研究尚且不足，学界对道路结构改造如何影响野生动物路杀事件与减缓措施的实际效果，也所知甚少。本研究依托一段150公里道路拓宽工程前后的路杀监测记录，结合新建与既有野生动物下穿通道（wildlife underpass），评估了道路拓宽以及距离该类通道的远近对大中型哺乳动物路杀事件的影响。研究人员根据物种的移动能力与对人类干扰的敏感程度，将受影响的16个物种划分为三组。16个物种中有4个在道路拓宽后路杀事件数量显著升高。尽管我们原本预期野生动物下穿通道附近的路杀事件会有所减少，但实际情况通常是该区域的路杀发生率高于随机水平。这一研究结果表明，我们亟需采用更为有效的野生动物减缓措施，例如将适配的围栏与下穿通道相结合的方案。