In the early 1970s, an investigation of reported shootings and poisonings of eagles in Wyoming and other western states led to evidence that eagles were also being electrocuted on power lines. Since then, the utility industry, wildlife resource agencies, conservation groups, and manufacturers of avian protection products have worked together to understand the causes of raptor electrocution and to develop and implement solutions to the problem. Those efforts have improved our understanding of the biological factors that attract raptors and other birds to power lines, and the circumstances that lead to avian electrocutions. This publication, Suggested Practices for Avian Protection on Power Lines: The State of the Art in 2006, summarizes the history and success of over three decades of work. It springs from three previous editions of Suggested Practices for Raptor Protection on Power Lines, and has been expanded and updated to assist those concerned with complying with federal laws, protecting and enhancing avian populations, and maintaining the reliability of electric power networks. Discoveries of large numbers of electrocuted raptors in the early 1970s prompted utilities and government agencies to initiate efforts to identify the causes of and develop solutions to this problem. Literature from the 1980s and 1990s continued to document electrocu- tions of raptors throughout the world. Now, reports of electrocutions of birds other than raptors are appearing in the literature and the impacts of avian interactions on power reliability are becoming more evident. Three federal laws in the United States protect almost all native avian species and prohibit “taking,” or killing, them. The Migratory Bird Treat Act protects over 800 species of native, North American migratory birds. The Bald and Golden Eagle Protection Act provides additional protection to both bald and golden eagles. The Endangered Species Act applies to species that are federally listed as threatened or endangered. Utilities should work with the U.S. Fish and Wildlife Service and their state resource agency(ies) to identify permits and procedures that may be required for nest management, carcass salvage, or other bird management purposes. Bird electrocutions on power lines result from three interacting elements: biology, environ- ment, and engineering. The biological and environmental components that influence electrocution risk include body size, habitat, prey, behavior, age, season, and weather. Of the 31 species of diurnal raptors and 19 species of owls that regularly breed in North America, 29 have been reported as electrocution victims. Electrocutions have also been reported in over 30 non-raptor North American species, including crows, ravens, magpies, jays, storks, herons, pelicans, gulls, woodpeckers, sparrows, kingbirds, thrushes, starlings, pigeons, and others. Avian electrocutions typically occur on power lines with voltages less than 60 kilovolts (kV). Electrocution can occur when a bird simultaneously contacts electrical equipment either phase-to-phase or phase-to-ground. The separation between energized and/or grounded parts influences the electrocution risk of a structure. Electrocution can occur where horizontal separation is less than the wrist-to-wrist (flesh-to-flesh) distance of a bird’s wingspan or where vertical separation is less than a bird’s length from head-to-foot (flesh-to-flesh). In this document, 150 cm (60 in) of horizontal separation and 100 cm (40 in) of vertical separation are recom- mended for eagles. Utilities may choose to adopt these recommendations or modify their design standards based on the species and conditions at issue. Single-phase, two-phase, or three-phase configurations constructed of wood, con- crete, metal, fiberglass, or other materials can pose avian electrocution risks if avian-safe separation is lacking. In particular, structures with transformers or other exposed, energized equipment account for a disproportionate number of avian electrocutions. Both avian-safe new construction and retro- fitted existing structures should be used to reduce avian electrocution risk. The principles of isolation and insulation should be considered when designing or retrofitting structures. Isolation refers to providing adequate separation to accommodate avian use of structures and should be employed where new construction warrants avian-safe design. Insulation refers to covering exposed energized or grounded parts to prevent avian contacts. Although equipment that is covered with specifically-designed avian protection materials can prevent bird mortality, it should not be considered insulation for human protection. In habitats where natural nest substrates are scarce, utility structures can provide nesting sites for raptors and other birds. Likewise, many birds use power poles and lines for perching, roosting, or hunting. Bird nests on utility structures can reduce power reliability. Nest management, including the design and installation of platforms on or near power structures, can enhance nesting while minimizing the risk of electrocution, equipment damage, and loss of service. Utilities are encouraged to collect data on bird-related outages to quantify the impacts of birds on power systems, and to develop measures for preventing bird mortalities and their associated outages. In 2005, the Avian Power Line Interaction Committee and the U.S. Fish and Wildlife Service announced their jointly developed Avian Protection Plan Guidelines (Guide- lines) that are intended to help utilities craft their own avian protection plans (APPs) for managing avian/power line issues. An APP should provide the framework necessary for implementing a program to reduce bird mortalities, document utility actions, and improve service reliability. It may include the following elements: corporate policy, training, permit compliance, construction design standards, nest management, avian reporting system, risk assessment methodology, mortal- ity reduction measures, avian enhancement options, quality control, public awareness, and key resources. The Guidelines present a comprehensive overview of these elements. Although each utility’s APP will be different, the overall goal of reducing avian mortality is the same. An APP should be a “living document” that is modified over time to improve its effectiveness.
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