Birds do not get electrocuted on power lines, but isn't it erroneous to say they don't "complete the circuit"

Question

I realize that birds don't get electrocuted because electricity would rather proceed through the powerline with less resistance (I know it doesn't think, but that's the best way I could say it). Nevertheless the birds do put both feet on the powerline. Hence the powerline, the bird's feet and the bird's body do form a closed loop, right? Hence is does complete a circuit. If the bird was made of metal, current would travel through it, right?

Answer 1

The electricity would rather pass through the wire which has far greater conductivity than the bird. Think of it as a short circuit.

It's the same thing that happens when you decide to connect another wire across wires which connect a light bulb. The light bulb might glow faintly if the wire is of high enough resistance but most likely the wire would have let the electricity bypass the bulb, and forms a "short circuit". This is even though the bulb can conduct electricity.

The bulb is then effectively "out" of the circuit which the electricity is flowing through, even though it is connected physically. Same with the bird. Electricity doesn't flow through the bird. So it's not part of the circuit.

Unless of course you are talking about a bird which has equal resistance to the wire it is on, then the electricity would be split equally and there would be a parallel circuit formed, but you know that birds don't really light up our streets by landing on wires so they don't really conduct electricity that well ( especially since they are not grounded ).

To illustrate better:
Imagine a complete circuit, now you add a crocodile clip to a bare wire, and a wire runs from that crocodile clip, there is no reason for electricity to run through that wire unless it is grounded. Take another similar crocodile clip with a wire and attach it to the same bare wire. Same as before, no electricity will flow through it unless it is grounded. Now attach those 2 crocodile clips together, why would electricity pass through either of them now? There still isn't any potential difference between the two crocodile clips to get electricity flowing through them, like connecting wires to the terminals of a dead battery. That's your "bird" for you.

Answer 2

Complete circuit - no. There is not enough delta-V (difference in potential) between the bird's left foot and right foot. Only if the bird presented resistance nearly equal to or less than the wire. The difference in potential over the approx. 2" of wire is not enough to allow current to flow through the bird. If resistance of the bird were the same as the wire, then the theoretical current through the bird would be half the total current of that being carried by the wire - bad news for the bird. Now if a bird were to have one foot on a high side and the other on the neutral wire, 'up in smoke' comes to mind. But with both feet on the same wire, no ground path exists, so no current flow.

Answer 3

No, even if the bird was metal, what you'd have is a short shunt across a short piece of wire. What generates the current is the voltage differential.

Say the cable is 1 mile in length and that it carries 10,000V. Typical distribution loss is on the order of 5%, so the total voltage drop along the cable is 500 V. 2 inces out of 1 mi translates into 16 millivolts, hardly enough to be noticed by anyone or anything.

Compare that to connecting across the supply wires and getting the full benefit of 9,500 V.

Answer 4

2 problems. First the wires are insulated where they land and thus cannot pass any electricity to the birds. The second problem is that the bird is not grounded. the current would usually pass through an object to reach it's grounding point.
(That's why people get zapped on ladders, or while climbing poles.
Small animals also tend to get zapped where the wires connect to the poles for the same reason.

Answer 5

It could, but it probabley wouldnt. Electricity follows physics, and would rather travel in a straight line than around a loop. I dont remember how to explain it, but it will only get electrocuted if it touches another wire. I know there is a simple explanation, but i cant think of it right now.

Answer 6

no
u need a second wire not a second foot
no circuit complete with just one battery terminal now is there?

Answer 7

most likely but birds arent metal so that wont happen

Answer 8

no, because the bird isn't "grounded"