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CEC-PIER: Funded Projects
Evaluating and Reducing Avian Collision at the Cosumnes River Preserve
Sub-Contractor: Marcus L. Yee
Sub Contract Project Manager: Marcus L. Yee
Contract Project Manager: Brian Walton
Commission Contract Manager: Linda Spiegel
The Issue
The risk of avian collision with power distribution lines in California has not been adequately assessed nor has the fatality rate due to collisions been calculated. To date, efforts to reduce avian interactions with power structures in California have been largely ineffective. Devices designed to divert birds from danger have not yet been tested rigorously in California. The value of these devices in low visibility fog conditions, common during winter months throughout the Central Valley of California, has not been addressed at all. The Central Valley is an important part of the Pacific Flyway, which accommodates millions of birds each year.
Project Description
Goal: The overall goal of this study is to evaluate aerial marking devices, especially in low visibility fog. Secondarily, the results of this evaluation will be used to develop a management plan aimed at reducing Sandhill Crane power lines strikes on Staten Island. This investigation will be accomplished with participation by Pacific Gas and Electric’s (PG&E) avian protection program and in cooperation with The Nature Conservancy and Cosumnes River Preserve.
Study site: The Cosumnes River Preserve is located on the 9,173 acre Staten Island near Sacramento in the San Joaquin Delta. It is the ideal setting for assessing avian diversion tools in California for three major reasons: the island is a wintering ground for tens of thousands of migratory waterfowl as well as the threatened-status Sandhill Crane, whose principal cause of post-fledge mortality was found by Shlorff (1994) to be collisions with power lines; a 7-mile, single, three-phase distribution line bisects the island cutting through avian feeding and roosting sites; and frequent tule fog, typical of Central Valley winters which obscures the power line from view.
The project can be divided into three phases:
Risk assessment
M. Yee will calculate mortality along the distribution line prior to any manipulation, as well as bias errors, to compensate for scavenger removal of carcasses, unsearchable habitat patches, and searcher oversight. Over-flight observations and habitat exploration will allow him to determine of the most appropriate test diverter apparatus and its placement.
Field-test of diversion devices
PG&E will purchase and install avian flight diverters. M. Yee will compare avian mortality along distribution lines before and after installation as well as between line segments with and without diverters over the same period of time.
Establish a management plan to reduce sandhill crane collisions with power lines at Staten Island.
The Nature Conservancy and Preserve Staff will collaborate with M Yee to monitor avian behavior in relationship with diversion devices with particular attention being given to the sandhill crane. This habitat use and behavioral data in conjunction with the success rating of diversion devices will allow the development of a plan aimed at lowering the local mortality rate of this threatened species.
Final Report
A final report will be published on the PIER website in March 2007. Scientifically valuable findings and recommendations will be submitted for publication in appropriate journals and conferences. Project results were presented in a workshop at the Raptor Research Foundation Annual North American Meeting mid-November 2004.
Contacts
Brian Walton: (831) 459-2466
Marcus Yee: (916) 551-1870
