A bird can sit safely on a high-voltage power line because voltage alone is not enough to cause a dangerous shock.
Current has to flow through the body.
Current needs a voltage difference
Electric current moves when there is a difference in electrical potential between two points.
A bird standing with both feet on the same wire has almost the same electrical potential at both feet.
Very little current therefore flows through the bird.
The wire is the easier path
The wire is designed to conduct electricity extremely well.
The bird’s body provides no useful shortcut if both feet are on essentially the same point in the circuit.
When would the bird be in danger?
If the bird touched two wires at different voltages, current could travel through its body.
The same could happen if it touched a live wire and a grounded structure at the same time.
Now the body would bridge a meaningful voltage difference.
Why can a person get shocked from electricity?
A person touching a live conductor while also connected to ground can provide a path for current.
The danger depends on voltage, current path, resistance, and contact conditions.
This is very different from a small static shock from a doorknob, which is a brief discharge of built-up charge.
So is the bird immune to electricity?
Not at all.
It is simply positioned so there is almost no voltage difference across its body.
One wire under both feet is safe under ordinary conditions.
Bridging two electrical potentials is not.
And that’s the short explanation.
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