Power Lines and Birds: Drivers of Conflict-Prone Use of Pylons by Nesting White Storks (Ciconia ciconia)

Abstract

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.

White stork movements reveal the ecological connectivity between landfills and different habitats

“…To avoid overcomplicating the network, we joined close polygons of similar land use to create a single node if they were separated by up to 10 km. A similar merging operation was used by Merken et al [ 43 ], and spatial autocorrelation for white storks breeding in southern Spain was estimated to be 9–12 km [ 12 ]. In the case of wetland polygons, we included a buffer around the shoreline because this is a favoured habitat for white storks.…”

“…This may lead to human-wildlife conflicts (e.g. [ 12 ] but also to ecological dis-services. When feeding on landfills, white storks ingest a wide range of solid waste such as plastics, metals, textiles or glass [ 7 , 49 ], antibiotic resistant bacteria [ 28 , 50 ] and resistance genes [ 31 ].…”