Question

Why is it that bird can sit over a suspended wire without any harm whereas touching it on the ground can give a fatal shock?

Answer 1

as long as the bird is not touching the ground the current does not pass through there body as there is no voltage difference and the second reason is the wire is a better conductor then bird and current always follows the shortest path.

Answer 2

Answer:

A bird can sit over a suspended wire without any harm whereas touching it on the ground can give a fatal shock because the circuit between the bird sitting on the live wire and the earth is not complete and no current flows through the body of the bird which remains safe.

However, if a bird touches the ground and also touches the same wire, the circuit to the earth is complete through his body and a heavy current passes through his body, causing a fatal shock.