No abstract

Electrocution on overhead power structures negatively affects avian populations in diverse ecosystems worldwide, contributes to the endangerment of raptor populations in Europe and Africa, and is a major driver of legal action against electric utilities in North America. We investigated factors associated with avian electrocutions so poles that are likely to electrocute a bird can be identified and retrofitted prior to causing avian mortality. We used historical data from southern California to identify patterns of avian electrocution by voltage, month, and year to identify species most often killed by electrocution in our study area and to develop a predictive model that compared poles where an avian electrocution was known to have occurred (electrocution poles) with poles where no known electrocution occurred (comparison poles). We chose variables that could be quantified by personnel with little training in ornithology or electric systems. Electrocutions were more common at distribution voltages (≤ 33 kV) and during breeding seasons and were more commonly reported after a retrofitting program began. Red-tailed Hawks (Buteo jamaicensis) (n = 265) and American Crows (Corvus brachyrhynchos) (n = 258) were the most commonly electrocuted species. In the predictive model, 4 of 14 candidate variables were required to distinguish electrocution poles from comparison poles: number of jumpers (short wires connecting energized equipment), number of primary conductors, presence of grounding, and presence of unforested unpaved areas as the dominant nearby land cover. When tested against a sample of poles not used to build the model, our model distributed poles relatively normally across electrocution-risk values and identified the average risk as higher for electrocution poles relative to comparison poles. Our model can be used to reduce avian electrocutions through proactive identification and targeting of high-risk poles for retrofitting.

No abstract

Raptor and corvid electrocutions cause continental conservation concerns for breeding, migrating, and wintering birds. Although concerns are widespread, mitigation is implemented primarily at local scales of individual electric utilities. By not considering landscape-scale patterns, conservation strategies may fail to focus mitigation where efforts are needed most. To enable resource managers to consider electrocution risk at larger scales, we developed a regional model of distribution power pole (pole) density in a grid of 1-km 2 cells throughout Colorado and Wyoming. To do so, we obtained data on pole locations from a sample of electric utilities covering 31% of Colorado and Wyoming, and developed a predictive model of poles throughout the remainder of the 2 states. Pole density was influenced by road lengths, number of oil and gas wells, slope, development, and land cover. Poles were densest in areas with high road lengths, high numbers of wells, and relatively flat terrain, and in areas developed for agriculture or human residences. When model predictions are viewed together with species-specific habitat maps, locations where high pole densities overlap habitat suggest areas where mitigating electrocution risk could be prioritized. Communication between resource managers and local utilities could then clarify the poles that caused the highest risk to raptors from electrocution. Thus, the model provides a framework for systematic spatial prioritization in support of regional conservation planning to minimize electrocution of raptors and corvids. Ó 2016 The Wildlife Society.

No abstract

Golden eagle (Aquila chrysaetos) electrocution on power poles is a global conservation problem with an estimated 504 eagles electrocuted annually in North America alone. Despite widespread use of mitigation techniques to retrofit existing poles and to build new poles to avian‐friendly standards, electrocution remains a leading anthropogenic cause of death for the golden eagle. To assist electric utilities, wildlife managers, and the public in understanding eagle electrocution risk, we reviewed and synthesized risk factors and mitigation techniques from published literature from 1940 to 2016. Eagles have 8 electrocution risk factors: pole design, eagle age, morphology, land cover and topography, prey availability, season, weather, and behavior. Pole configuration was the most frequently identified electrocution risk factor and electrocution incidents were most often associated with distribution level (<69 kV) equipment poles. Age was the second most frequently identified risk factor, with juvenile eagles electrocuted at approximately twice the rate of subadults or adults. Risk was also associated with large body size, high‐quality habitat, high prey density, winter dispersal, inclement weather, and intraspecific interactions. Risk modeling based on these factors may assist electric utilities and other stakeholders in identification of high‐risk poles at the regional scale. High‐risk poles need prioritization for retrofitting by electric utilities. Compensatory mitigation funding becoming available through eagle take permitting may be useful in offsetting costs to utilities. Electrocution mitigation efforts strategized by region to target high‐risk poles could result in substantial reductions of golden eagle annual mortalities. © 2018 The Wildlife Society.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.