Avian Electrocutions on Incorrectly Retrofitted Power Poles
Avian electrocutions on power poles (hereafter, poles) are a global conservation concern, particularly for large-bodied species like Golden Eagles (Aquila chrysaetos). Retrofitting poles through increasing clearances (separation) between components, adding insulation to components, or adding redirection materials like perch discouragers reduces risk, but electrocutions may occur even on retrofitted poles. We evaluated 52 retrofitted poles where 56 birds, including 17 Golden Eagles, were electrocuted after retrofitting. We used burns on pole equipment and carcasses to identify precise pole-top locations where electrocutions occurred, and we identified three categories of retrofitting errors: product design, mitigation plan, and application. Product design errors (n = 9 poles, 6 Golden Eagles) occurred when products did not sufficiently cover energized equipment. Mitigation plan errors (n = 30 poles, 6 Golden Eagles) occurred when retrofitting plans did not include coverage of all energized components on a pole. Application errors (n = 13 poles, 5 Golden Eagles) occurred when the correct products were installed incorrectly. Retrofitting mistakes were identified in this study retroactively when avian electrocutions occurred on poles described as retrofitted. This is typical of how retrofitting mistakes are identified by the electric industry, which can lead to expensive duplicate efforts, and ongoing avian electrocutions. These can be avoided if retrofitting is done correctly initially. This study provides insight to electric utility personnel and wildlife managers interested in proactively evaluating the thoroughness of retrofitting, facilitating immediate identification and correction of retrofitting errors, increasing cost effectiveness, and reducing avian electrocution mortality. Las electrocuciones de aves en postes eléctricos (de aquí en adelante, postes) son una causa de preocupación para la conservación a nivel mundial, particularmente para especies de gran tamaño como Aquila chrysaetos. La corrección de postes a través del aumento de la separación entre los componentes, la adición de aislamiento a los componentes, o la adición de materiales que ahuyenten a las aves tales como elementos que disuaden el posado, reducen el riesgo, pero las electrocuciones pueden ocurrir incluso en postes corregidos. Evaluamos 52 postes corregidos en los que 56 aves, incluyendo 17 individuos de A. chrysaetos, se electrocutaron tras su corrección. Utilizamos señales de quemaduras en el equipamiento de los postes y en los cadáveres para identificar de manera precisa el lugar del poste donde ocurrieron las electrocuciones, e identificamos tres categorías de errores de corrección: diseño del producto, plan de mitigación y aplicación. Los errores en el diseño del producto (n = 9 postes, 6 individuos de A. chrysaetos) ocurrieron cuando los productos no cubrieron de manera suficiente el equipamiento electrificado. Los errores del plan de mitigación (n = 30 postes, 6 individuos de A. chrysaetos) ocurrieron cuando los planes de corrección no incluyeron la cobertura de todos los componentes electrificados en un poste. Los errores de aplicación (n = 13 postes, 5 individuos de A. chrysaetos) ocurrieron cuando los materiales correctos fueron instalados de manera incorrecta. Los errores de corrección fueron identificados en este estudio de forma retroactiva, cuando las electrocuciones de aves ocurrieron en postes descritos como corregidos. Esta es la manera típica en la que la industria eléctrica identifica los errores, los cuales dan lugar a esfuerzos duplicados que resultan caros, así como a nuevas electrocuciones. Estos errores pueden ser evitados si la corrección se realiza de manera correcta desde el inicio. Este estudio proporciona recomendaciones para el personal del servicio eléctrico y los gestores de vida silvestre interesados en evaluar todos los detalles de la corrección, facilitar la identificación inmediata y la corrección de los errores de reacondicionamiento, aumentar la rentabilidad de los costes y reducir la mortalidad de las aves por electrocución. [Traducción del equipo editorial]Abstract
Resumen
Avian electrocution risk is highest on poles with no mitigation, and lowest on poles with avian-friendly retrofitting achieved through insulation or separation.
Common power pole (pole) components useful in understanding retrofitting mistakes for birds electrocuted between January 2013 and December 2015 on poles described as retrofitted, in Arizona, Colorado, Idaho, New Mexico, Utah, and Wyoming, U.S.A. See APLIC (2006), Dwyer et al. (2013), and APLIC (2015) for additional illustrations. See Table 1 for component names.
(A) Burns on the neck and axillary feathers of the carcass of an electrocuted Bald Eagle. (B) Burns on the left wing of the carcass of an electrocuted Golden Eagle suspended on energized equipment. (C) The feet of an unidentified electrocuted Buteo species grasping an energized jumper. (D) Arc mark on a grounded guy wire connection following the electrocution of a Bald Eagle.
Arrows indicate retrofitting errors. (A) Product design error: covers installed on cutouts but energized tops remain exposed. (B) Product design error: arrester cap dislodged and locking horns exposed. (C) Product design error: arrester and jumpers covered, but bushing cover dislodged. (D) Mitigation plan error: jumpers covered, but conductor cover (upper arrow) and deadend cover (lower arrow) absent. (E) Mitigation plan error: the foot of a Chihuahuan Raven on an arrester ground resulting from routing the uninsulated ground wire below the exposed primary conductor. (F) Mitigation plan error: all energized equipment covered, except deadend cover absent.
Arrows indicate retrofitting errors. (A) Mitigation plan error: jumpers covered, but arrester covers (left arrows) and cutout covers (right arrows) absent. (B) Mitigation plan error: jumpers and arresters covered, but bushing covers not installed. (C) Mitigation plan error: bushings and jumpers between bushings (circles) covered, but jumpers exposed above (arrows). (D) Mitigation plan error: insufficient clearance between open switch above and grounded arrester connection below. Redirection materials on the upper crossarm may also push birds into perching near energized components on the lower crossarm. (E) Application error: jumper and arrester covered, but a gap in jumper coverage exists between retrofitting products. (F) Application error: all equipment covered, but gaps in coverage where jumpers connect.
Arrows indicate retrofitting errors. Circles indicate correct retrofitting. (A) Cutout covers fully covering all energized parts on the upper portion of cutouts minimize avian electrocution risk. (B) Cutout cover fully covering all energized parts on the upper portion of cutouts minimize avian electrocution risk. (C) Golden Eagle electrocuted on a pole fitted with early model perch discouragers, ineffective in redirecting perching. (D) An Osprey perched next to a plastic owl, ineffective in redirecting perching. (E) Jumper insulation inserted inside insulating covers on arresters and bushings to minimize electrocution risk.
Contributor Notes
Associate Editor: Joseph B. Buchanan