Managing nesting by Chihuahuan ravens on H‐frame electric transmission structures

Abstract

AbstractElectric utility structures occur widely in natural and human‐dominated landscapes and are often used by birds for nesting. Nests can cause power outages, fires, and electrocution of birds and their young, particularly if nests occur directly above energized equipment and incorporate metal wire. Chihuahuan raven (Corvus cryptoleucus) nests often contain metal wire and occur over energized equipment. To explore a proactive risk mitigation strategy we deployed novel nest diverters on 51 structures supporting a 230 kV H‐frame transmission line in Kiowa and Bent Counties, Colorado, USA, and compared nesting on these structures with nesting on 66 structures without nest diverters on the same line. Chihuahuan ravens placed nest material on 7% of treated structures and 43% of untreated structures and nested on 0% of treated structures and 34% of untreated structures. Chihuahuan ravens were less likely to attempt to nest on, or actually nest on, structures treated with nest diverters. Future research should evaluate nest diverters over larger spatial and temporal scales and compare prey populations in areas where ravens are excluded to prey populations in areas where ravens persist. © 2012 The Wildlife Society.