Why do birds sit on power lines?
We might have observed one time or the other that the birds sit on the electricity wires. They might have used these power lines for taking rest as they are available very high above and easy to approach. When the birds are flying high in the air they can just relax for few moments on the power lines which is really comfortable for them to do high above in the air instead of coming down and rest on the ground. Sometimes, they also choose trees and house terraces to take rest as they are also high above in the air. They probably choose all these places to rest for one reason that they can take a break in their flight on these structures without any harm and conveniently.
Also, the power lines due to resistance in them will become warm when the electricity continuously flows through them. So, it might be very relaxing for the birds to sit on the warm wires. Probably, the birds are finding way to escape from ground predators when they sit on the power lines that are high above. There is a doubt among people that when the birds sit on the high voltage power lines, they are not getting electrocuted. Electricity passes into a circuit only when there is a potential difference that exists between the ends of the circuit. If a bird sits on the power line, it does not complete a circuit as the bird does not come in contact with another wire or ground. A potential difference is created when the bird touches another wire simultaneously along with one which might kill the bird as the current will pass into it due to the potential difference.
Birds mostly sit on the power lines during the dawn and dusk. This might be there because they are planning for food search and migratory flight for that day in the morning. They might also be planning for night stay in the evenings.