2006

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.

THE ISSUE
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 electrocutions 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.

REGULATIONS AND COMPLIANCE
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 agencies) to identity permits and procedures that may be required for nest management, carcass salvage, or other bird management purposes.

BIOLOGICAL ASPECTS OF AVIAN ELECTROCUTION
Bird electrocutions on power lines result from three interacting elements: biology, environment, 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, king birds, thrushes, starlings, pigeons, and others.

SUGGESTED PRACTICES: POWER LINE
DESIGN AND AVIAN SAFETY
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).