The Use of Mobile Nesting Platforms to Reduce Electrocution Risk to Ferruginous Hawks

Electrocution on low-voltage power lines is a well-known source of mortality for raptors. Electrocution risk is particularly high for large raptors that can bridge components and make lethal contact, and for raptors living in open landscapes where power poles can be attractive nest or perching sites. Thus, large, grassland-obligate species like the Ferruginous Hawk (Buteo regalis), a legally endangered and threatened species in Alberta and Canada, respectively, are at high risk of electrocution. We used mobile (temporary) versions of artificial nest platforms (ANP) to relocate Ferruginous Hawks nesting on power poles at two sites on Canadian Forces Base Suffield, in Alberta, Canada. At one of these sites an adult female and a fledgling were electrocuted in 2014 and 2015, respectively, prior to introduction of a mobile ANP. In 2016, we relocated this nest to a mobile ANP 23 m away from the original nest pole, and the nesting attempt was successful. In 2017, we installed nest deterrents and insulation on the original nest pole and we installed a permanent ANP 465 m away. From 2017 to 2019, we moved the mobile ANP in stages toward the permanent ANP, with Ferruginous Hawks either nesting on or occupying the mobile ANP each year. We anticipate Ferruginous Hawks transferring to the permanent ANP soon. We also attempted our mobile-ANP-to-permanent-ANP approach at a similar power pole elsewhere on the base in 2016. In 2017, a Ferruginous Hawk pair nested on the permanent ANP so we removed the mobile ANP. This pair did not return in 2018 or 2019. Despite mixed results, use of mobile ANPs as a tool to move nesting raptors away from power poles that are not avian-safe may be a viable electrocution mitigation strategy.