Frequently Asked Questions
Injury and mortality can result when birds collide with power lines. Collisions occur most often in areas where a transmission line intersects bird breeding and feeding areas, such as bodies of water or wetlands. Transmission lines are often difficult for birds to see and can sometimes appear invisible due to background or low light conditions. The risk is believed to be highest for waterfowl as they are not able to maneuver quickly around the lines.
Birds such as hawks, eagles, owls, osprey and ravens commonly use utility structures and substations for perching, roosting, hunting and nesting. Electrical contacts typically occur on voltages less than 69 kV (69,000 volts) where separation between the wires is minimal.
A bird is at risk of electrocution on a structure if it contacts two energized components or an energized component and a grounded component. Birds are typically at risk on distribution poles where the electric and grounded components are closer together rather than on larger transmission structures where they are further apart. In substations, electrocutions typically occur in the low, 25 kV side where there are minimal clearances. Power outages are common when a bird is electrocuted in a substation.