Evaluating the Risk of Electrocution on Endangered Crowned Eagles (Harpyhaliaetus coronatus) in Central Argentina

GALMES, M. A.; SARASOLA, J. H.; GRANDE, J. M.; VARGAS, H.

San Carlos de Bariloche

Conferencia; I Worldwide Raptor Conference (Raptor Research Foundation Annual Conference 2013 - III Neotropical Raptor Network Conference - WWGBP VII International Conference on Birds of Prey and Owls); 2013

CRUB-Universidad Nacional del Comahue; Neotropical Raptor Network-The Peregrine Fund; World Working Group On Birds Of Prey And Owls; Raptor Research Foundation

The Crowned Eagle is one of the largest eagles of South America and is categorized by the IUCN as a globally endangered species.  Habitat loss and fragmentation, and direct persecution have been identified as the main threats for the species.  Electrocution and collisions on power lines pose important threats to large birds of prey worldwide.  In Argentina, there are records of electrocuted Crowned Eagles, but no systematic assessment has been done to quantify the potential impact of this mortality factor to this eagle.  We quantified mortality by electrocution of Crowned Eagles and other birds and identified the most dangerous types of electricity pylons at six different sections of power lines at semiarid forest in central Argentina. From November 2011 to December 2012, we visited the power lines six times.  We described the structural design (type of material used for construction, presence and position of jumpers, type and position of insulators, size of crossbeam) of 3114 electricity pylons throughout 355 km covering an area of approximately 12000 km2 that supports around 30 breeding territories of Crowned Eagles.  We found 35 dead individuals of three bird families: Psittacidae 48.6%, Cathartidae 37.14% and Accipitridae 14.3% (the five individuals being Crowned Eagles).  Such records represent 25 singular electrocution events (1.4 bird/event).  Regarding birds of prey, most electrocution events occurred on pylons with jumpers above the crossbeam (96%) and in concrete pylons (84%).  This is highly relevant because only 2% of theinspected pylons had jumpers above the crossbeam and 10% were concrete pylons.  All electrocution events were associated with rigidinsulators above the crossbeam or horizontal insulators.  Our results thus prove that electrocution is a relevant cause of mortality for Crowned Eagles in our area, and urgent mitigation actions are needed to reduce this mortality factor.