Give Now

A Moment of Science

Why Aren’t Bird Electrocuted When They Perch On Power Lines?

Have you ever wondered why birds aren't electrocuted by the currents that flow through high-voltage power lines?

bird on a wire

Photo: Jalal Hameed Bhatti (Flickr)

No zap for this bird!

It’s not unusual to see lines of birds perched on power lines. But did you ever wonder why birds aren’t electrocuted by the currents that flow through these high-voltage wires?

You might think it’s because the wires are insulated, but they’re actually not insulated at all — that’s why downed power lines are so dangerous. No, the only reason why birds on power lines usually aren’t electrocuted is because the wire is the only thing they’re touching!

Why No Zap?

Like all energy, electricity seeks equilibrium, or balance. That means electricity will flow from high-energy areas to areas of less energy, always using the path of least resistance. So if the bird has one foot on our original wire, and the other foot on, for example, the ground or on a different wire with less voltage, the bird would be electrocuted. The electricity would pass through the bird on its way from the high-voltage line to the lower-voltage line or the ground.

But as long as both of the bird’s feet are on the same wire (or wires of the same voltage), the bird is safe. The current doesn’t have anywhere else to go, so the electricity won’t pass through the bird–it stays on the path of least resistance, the wire.

Don’t Try This At Home!

This would work for humans, too–if you were to hang suspended from one of these wires, you wouldn’t be electrocuted, as long as you didn’t get too close to anything else, like a telephone pole or the ground. But don’t try this experiment at home! If you want proof, just look up at the birds on the wires!

  • jalalspages

    Informative indeed. And thanks for using my photo from Flickr and having it attributed to me.

  • Shincbends

    Nice capture !

  • Marie Nicole Sorongon

    oh .. now iknow

  • Myrtonos

    The bird’s feet being safe on one wire might be the case with DC, but I believe that with AC, at voltages higher than the power lines the bird is not safe even with both talons on the same wire because HVAC electrifies the air around the wire.

  • hi

    i always wondered why and now i know!

  • Robert Bass

    It is safe for birds regardless if it is AC or DC. Pretty much all overhead wiring in the USA is AC and birds are not harmed when they perch on one wire.

  • Myrtonos

    But I said at voltages higher than the power lines, not at the power line voltage. I’m saying that at many kilovolts, the halo effect may well cause electrocution even without touching the other wire.

Stay Connected

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from A Moment of Science:

Support for Indiana Public Media Comes From

About A Moment of Science

Search A Moment of Science