Contact with Live Wires: Power lines carry high-voltage electricity, and when a bird touches a live wire, it completes an electrical circuit between the wire and the ground or another grounded object. This results in the flow of electric current through the bird's body, causing electrocution.
Proximity to Multiple Conductors: Birds often perch on power lines because they provide convenient resting spots. However, many power lines consist of multiple conductors, including energized (live) wires and neutral wires. When a bird's wings or body simultaneously touches both a live wire and a neutral wire or a grounded object, it can result in electrocution.
Wet Conditions: Wet feathers and damp environments can increase the risk of electrocution for birds. When feathers are wet, they become better conductors of electricity, reducing the resistance to the flow of electric current through the bird's body. This can increase the severity of electrocution.
Line Design: The design and configuration of power lines can also play a role in bird electrocutions. For example, older power lines may have exposed conductors, making them more accessible to birds. In contrast, modern power lines often incorporate various bird-safe designs, such as insulation and covers, to minimize the risk of electrocution.
It is important to note that electrocution is not the only hazard that birds face from power lines. Collisions with power lines can also cause injuries and fatalities, especially for larger birds with wider wingspans.
Efforts are being made by utility companies and conservation organizations to mitigate these hazards by implementing bird-safe practices and retrofitting existing power lines to reduce the risk of electrocution for birds.