Most people have been wondering even till date why birds sitting or perching on a high-voltage power line can't get shocked or electrocuted. It's really amazing tho! But there are reasons for this.
The copper wire in electrical wires is a great conductor of electricity. Therefore, electricity flows by the movement of electrons through conductors. So this copper allows electricity to flow easily along its surface.
Birds cells and tissues do not offer electrons an easier path than the copper wire they're already traveling along. As a result of this, the electricity bypasses the birds and keeps flowing along the wire instead. So, this makes birds not to be a good conductor of electricity.
Birds places their two feet on same wire, so this is making no potential difference to occur between the power cable and the birds. But had it been birds can touch two power cables at the same time, then, there would be a shock to such bird.
In addition, birds can not be electrocuted because it's just sitting on one wire, which simply means the electric circuit is incomplete. For the electric circuit to be completed, the body of the bird or let's say if the bird flap its wings, and the wings or other body parts touches a different wire from the one its sitting, that's when the bird would get shocked or electrocuted.
Why Would Human Get Electrocuted If Touch Just One Wire Like The Birds?
This is quite simple and straight forward, standing on the ground (earth), and at the same time touching one of these wires would result in electrocution because the earth is at different potential than the power line. This will allow current flow from the high-voltage wire, through the human ( or any such being) down to the earth, thereby causing a great shock to such being.
A single high-voltage wire would not be touched while hanging in the air, that's impossible unless if such person is a Power Line Maintenance Worker,
Therefore, other humans that are not power line maintenance workers, can not place their feet in the air but on something peradventure if such person would touch a power cable. Though, if that something is different from the ground (earth) but things like tables, stools that are free of moisture, there won't be any shock because all these objects do not conduct electricity except if got wet.
This picture below was screen grabbed from a video I watched about holding an electric fence without electrocuting the group. Video was made by Matthew Allen. The picture depicts a group of people holding hands with each other while standing on dry objects. But the first person on the right was holding an electric fence. Everyone stood on something and the experiment went as expected.
Furtherore, this is why the workers involved in power line maintenance always get this done easily. They mostly use helicopter for this course so that their feet would be on air while amending the faulty places.
Standing on a plastic stood would have been added, but just that plastics do conduct electricity. Actually, It is not all plastics that does. Plastics like polystyrene and polyethylene do not conduct electricity.
However, if the polymer is polar, that means, it has a dipole moment which can cause it to be conductive, but non-polar polymers are the ones used as insulators but polar polymers are not highly suitable for being used as insulators.
Though the non-polar polymer conducts electricity so poorly and that's why they are used to insulate electric cables but, by placing a thin film of metal onto a plastic sheet and mixing it into the polymer surface with an ion beam.
So compare to the birds, if they too can place parts of their body on ground and other parts on a high tension wire, that means they too will get shocked like human. But the single wire which is incomplete of electrical circuits is the one giving all birds advantage for them to sit on.
In Conclusion,
As for all these reasons, all birds can't be electrocuted while sitting on a high-voltage wire. And besides, it's not only birds, but also human (provided his or her legs are not touching ground like the way power line maintenance workers does. Hanging on a rope and placing their feet on air while repairing where necessary) and other animals like squirrels, cane rats, rabbits, and so on... They can't be electrocuted when walking through in as much their bodies are not touching another power cable at the same time.
I hope this article help clarifying the reason?
Thank you for your time!
All Images Used In This Article, Are Linked To The Respective To Owners
REFERENCES
PhysLink
Physics Stack Exchange
Science Made Simple
