Identifying Electric Distribution Poles for Priority Retrofitting to Reduce Bird Mortality

Publication Number:    CEC-500-2008-055

Abstract:

This report outlines the research findings on reducing bird mortality due to electrocution on electric distribution lines. Field studies were conducted during 2003-07 in two phases. During the study, one-time visits were made to 9,502 distribution poles. Fatality searches were conducted at each and data were collected on numerous variables identifying the environmental and hardware characteristics of each pole. The fatality searches documented 1,079 bird carcasses. Of these, 60 were killed by electrocution. Another 227 were highly-likely to have been electrocuted. This study’s data analyses were limited by using systematic sampling approach rather than a randomly-selected sample of poles and by the sample size of fatalities found during this study’s searches. The data were analyzed to yield an annual mortality at the poles in the sample studied of 0.06 birds per pole, of which 0.01 were raptors. The most dangerous poles were those supporting lightning arrestors or riser elements. Logistic regression was applied to the data to examine 22 different candidate models that could be selected to predict the electrocution risk associated with poles and thus identify and prioritize poles requiring retrofit. A preferred model was identified and demonstrated with example applications. Applying results of these models can have a direct affect on reducing bird mortality due to electrocutions on power poles. This research benefits California by conserving valuable natural resources, ensuring compliance with environmental laws and regulations, improving the reliability of the electric distribution system, and increasing safety and reducing risk to public safety because bird electrocutions are often the source of wildfires. Monitoring for electrocutions must be expanded into more regions so protective measures can be implemented over a broader geographic area.

Keywords: Avian electrocution, distribution lines, avian electrocution risk model, power pole retrofitting

Author(s):  BioResource Consultants, Carl G. Thelander, Christopher Costello, Brian Kara

Commission Division:    Technology Systems Division - R&D, PIER (500)

Office/Program:    PIER: Public Interest Energy Research

PIER Program Area:    Avian-Energy Mitigation Program

Date Report Completed:    April 2009

Date On Line:    04/14/2009

Acrobat PDF File Size: 66 pages, 1,600 kilobytes**