Bird collisions with power lines: prioritizing species and areas by estimating potential population-level impacts

Biodiversity ResearchAim: Power lines can represent an important source of bird mortality through collision. The identification of more susceptible species, in terms of expected populationlevel impacts, requires detailed biological and mortality information that is often difficult to obtain. Here, we propose a species prioritization method based on relatively easily accessed information, aimed to identify both species and areas with the potentially highest extinction risk due to collision with power lines. Location: As a case study, we applied this method to the communities of resident breeding birds of Spain and Portugal. Methods: For each considered species, the method takes into account the morphobehavioural susceptibility to collision with power lines, the susceptibility to extinction and the spatial exposure to collision with power lines. Results: Our method highlighted that the most susceptible species were large, longlived and slow‐reproducing birds, often habitat specialists with hazardous behavioural traits (especially flight height and flocking flight), with high spatial exposure to collision risk with power lines and unfavourable conservation status. Based on the distribution ranges of these species, we produced a map of hotspots for extinction risk due to collision of such priority species for each country. These areas should be considered a priority for the implementation of mitigation measures including route planning and wire marking. Main conclusions: Overall, the proposed method can be applied to any bird community in any geographic area of the world where information on power‐line distribution and published information on species traits, distribution and conservation status is available, generating valuable lists of both priority species and areas in which collision risk with power lines can potentially produce local or even global extinctionsinfo:eu-repo/semantics/publishedVersio

Wire Marking Results in a Small but Significant Reduction in Avian Mortality at Power Lines: A BACI Designed Study

10 paginas, 4 figuras y 4 tablesBackground: Collision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published. Methodology/Principal Findings: We provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV-45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking. Conclusions: Our results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.We thank A. Garcıa Fernandez and M. Carrasco for their assistance during the field work. We also thank J. Camaño and J. Velasco of HENARSA, and the electric companies Iberdrola, Union Fenosa and Red Electrica de España for their cooperation. S. Young reviewed the English. RB was contracted within the project CGL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation and later supported by a postdoctoral grant from Junta de Comunidades de Castilla-La Mancha. C. Ponce, C. Palacın, CM and BM were supported by contracts CSICHENARSA. This study was carried out within the Preventive, corrective and compensatory measures to balance the impact of the M-50 and R-2 highways on the population of great bustards and other steppe-land birds in the Important Bird Area Talamanca-Camarma and the Site of Community Importance Cuenca de los rıos Jarama y Henares, supported by a contract HENARSA-CSIC. Additional financial support was provided by project GL2008-02567 of the Direccion General de Investigacion, Spanish Ministry of Science and Innovation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe