Avian-Friendly Approaches to Power Lines
Birds on a wire have fascinated song writers and artists alike since the first power lines were constructed in the early 1900s. But to electric utilities, the same image conjures up something quite different.
The reality is, power poles and overhead lines pose a serious risk to avian species that nest or perch on electrical equipment. Electrocutions and collisions with wires result in deaths to thousands of birds each year.
Birds aren’t the only ones that suffer, however. These interactions can cause damage to power company equipment, resulting in power outages that affect customers, too.
Risks may vary depending on the species of bird involved. Birds with wide wingspans — such as eagles, vultures, water birds and hawks — can be electrocuted when making two points of contact with energized wires or equipment. Ducks, geese and other birds with large, heavy bodies often have difficulty maneuvering through power lines that cross water or feeding areas, making them a collision hazard.
The response from utilities to these risks can depend, in part, on the laws protecting the species. The Migratory Bird Treaty Act (MBTA) protects more than 1,000 species of birds that migrate across international borders. While the bald eagle is no longer a listed species under the Endangered Species Act, it and the golden eagle are still protected under the Bald and Golden Eagle Protection Act. An additional 147 species are included on the U.S. Fish and Wildlife Service’s national Birds of Conservation Concern list and receive protections under federal regulations.
Utilities that have experienced avian issues often respond with the development of an Avian Protection Plan (APP). APPs are corporatewide tools utilities use to document their steps to comply with bird protection laws and improve service reliability. An APP includes everything from corporate policies and construction design standards to reduce avian risk, to nest management actions, avian risk assessment methods, employee training, and mortality reporting methods.
Best Management Practices
To minimize bird impacts, new power lines are designed following best management guidelines and recommendations developed by utilities and resource agencies. These recommendations include using GIS data, biological field assessments and avian-use information to identify avian-use areas and select optimal siting routes to minimize bird impacts. Line designs that provide greater separation between wires — at least a 60-inch separation horizontally and a 40-inch separation vertically — or covering energized equipment with avian-safer materials also help to reduce the risk of electrocution or problem nests on power poles.
Utilities are also aided by the recommendations and suggested best practices published by the Avian Power Line Interaction Committee (APLIC), formed 30 years ago through a partnership of USFWS, the National Audubon Society, utilities and universities. APLIC members publish guidance documents and conduct workshops to offer solutions that can be used to retrofit existing infrastructure or design new lines to minimize risks to birds in the U.S. and abroad.
APLIC recommendations include measures to reduce risks of bird collisions by siting lines away from avian-use areas. Line voltage type, pole or tower structure design and wire configuration can also help reduce collision or electrocution risk.
All active nests — those where eggs or young birds are present — belonging to MBTA species are protected and cannot be disturbed, relocated or removed without a permit or authorization from USFWS. This also applies to active and inactive eagle nests. Problem nest issues can, however, be resolved with nest platforms placed away from the utility equipment to entice the birds to build their nests there in subsequent years.
Implementing these best practices is relatively simple and makes good business sense. The cost and time commitment to implement them, however, adds up when they must be repeated over hundreds of miles of power lines and substations within a utility’s service area.
When an electric utility has an APP and works with resource agencies to implement measures that reduce avian risks, these mitigation efforts not only protect birds and reduce risk of regulatory noncompliance, they also reduce outages. In the long run, that is good news for everyone who uses electricity.