Accidents on power lines are one of the most important causes of man-induced mortality for raptors and soaring birds. The factors that condition the hazard have been extensively studied, and currently there are a variety of technical solutions available to mitigate the risk. Most of the resources in conservation projects to reduce avian mortality now are invested in fieldwork to monitor the lines, which diverts the resources available to install actual corrective measures to mitigate bird hazard. Little progress has been achieved in the methodology to characterize line risk, which is an expensive, tedious, and time-consuming task. In this work we describe the use of low cost small unmanned aircraft systems (sUAS) equipped with on-board cameras for power line surveillance. As a case study, we characterized four power lines, geo-referenced every pylon in selected portions, and assessed their hazard for birds. We compare the effectiveness of two variants of the sUAS method for data acquisition and two methods of plane control. This work provides evidence of the usefulness of sUAS as a fast, inexpensive, and practical tool in conservation biology, adding to their already known applications in wildlife monitoring, the environmental impact assessment of infrastructures.
