Summary Avian electrocutions are a global conservation problem. Power outages associated with electrocutions are problematic for electric utilities focused on delivering reliable electric power. We used contextual data, photographs, line voltage, outage type and assessments of power line components to quantify outage-causing avian electrocutions throughout each of Iran’s 31 provinces. We evaluated records of 222 avian-caused outages involving 235 electrocuted birds in 2018. Of these, 14.5% involved species of conservation concern, and a few (at least eight) sparked fires when the plumage of electrocuted birds ignited and fell into dry vegetation. Most avian-caused outages (96%) involved distribution voltages, and 91% involved phase-to-ground contacts attributable to grounded concrete pylons with grounded steel crossarms. These are the most common type of power line structure in Iran. Insulators were involved in 37% of outage-causing avian electrocutions, fused cutouts 29%, transformers 33%, and midspan collisions 1%. Given the numbers of these components in the electrical system, fused cutouts and transformers were involved in more outage-causing avian electrocutions than expected due to chance. The average body size of electrocuted birds was largest for incidents involving suspension insulators, smaller for birds electrocuted on other insulators, and smallest for electrocutions on fused cutouts and transformers. Given that most avian electrocutions do not cause outages and given the similarity across electric systems in the region, our findings likely indicate a much larger avian electrocution concern throughout the middle east. Retrofitting power line components to reduce avian contacts would reduce impacts to wildlife and improve the electrical system’s reliability, reduce costs associated with unplanned outages, and reduce risks associated power line ignitions of fires.

Electrical pylons are frequently used by birds for perching, roosting, and nesting. These behaviors can lead to electrocutions, particularly when pylons are constructed of grounded concrete and steel crossarms, as they were in our study area near Arak, Iran. To address electrocutions of Eurasian Kestrels (Falco tinnunculus) and a variety of passerines nesting on a 20-kV distribution line, we documented construction and use of nests on pylons on a 34-km segment of power line in 2018. Following removal of nests by the electric utility operating the line, we installed nest boxes on pylons that previously supported nests, and in 2019 we documented use of those nest boxes. We predicted that after installation of nest boxes, numbers of Eurasian Kestrel nests would increase, and numbers of nests outside of nest boxes, avian electrocutions, and faults (electric current arcing from conductors to pylons) would decrease. All four predictions were validated. We documented 31 nests in 2018, including 3 Eurasian Kestrel nests. In 2019, we documented 6 nests outside of nest boxes, and 31 nests in nest boxes, including 16 Eurasian Kestrel nests. In 2018, we found 1 electrocuted Eurasian Kestrel, and 39 electrocuted passerines. In 2019, we found 3 electrocuted Eurasian Kestrels, 11 passerines, 2 Eurasian Eagle-Owls (Bubo bubo), and 1 Steppe Eagle (Aquila nipalensis). The rate of electrocutions per nest for Eurasian Kestrels decreased from 0.33 to 0.19, and the electrocution count for all birds decreased by 57.5%. Electrical faults, an indirect measure of potential avian electrocutions, decreased from 173 in 2018 to 120 in 2019. Although there is some risk that nest boxes on power poles could create ecological traps, our results suggest that in this study electrocutions and electrical faults were reduced, supporting conservation goals and electric power reliability goals while simultaneously reducing electric utilities' maintenance obligations.

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Energy infrastructure is expanding at a global scale and can represent a major threat to wildlife populations. Power lines are one of the main sources of human-induced avian mortality due to electrocution or collision, but many species use electricity pylons as a structure for nesting. Pylon nesting results in human-wildlife conflict because it can cause power outages and structural damage to power lines. The white stork (Ciconia ciconia) is a large-size semicolonial species that increasingly nests on pylons, causing growing operational and economic issues to power companies and energy consumers. In this study, the likelihood of problematic pylon use by nesting storks was predicted using a suite of explanatory variables related to the availability of foraging habitat and human disturbance. During a five-year period (2015–2019), we assessed the distribution of stork nests removed from the highly-risky top part of transmission pylons (220–400 kV) by power company technicians in South western Spain. A total of 839 nests were removed from 11% of the transmission pylons (n = 1196) during the study period. Pylon use intensified on pylons located near to landfills, surrounded by high proportion of grassland, and when close to freshwater sources (water body or river) and other occupied pylons. Human disturbance was unlikely to deter storks from using pylons and pylon use increased in urban areas. The approach used here to predict pylon use by nesting birds has applications for both human-wildlife conflict mitigation and conservation purposes where endangered species use human infrastructure. Power companies may use this kind of information to install anti-nesting devices (to reduce power outages and avian mortality or nesting platforms on suitable pylons (to promote pylons use by endangered species), and to account for the likelihood of conflict-prone use of pylons when siting future power lines.

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