Physics · Electrostatic Potential

A bird perches safely on a high-power bare electrical line carrying an alternating voltage, but a person standing on the ground touching the same line gets a severe fatal shock. This difference is primarily because:

1. Bird's claws have infinitely high dielectric breakdown strength
2. There is virtually zero potential difference across the bird's body, while a large potential difference exists across the person
3. The alternating frequency prevents electric flow through smaller animals
4. Bird's body resistance is strictly infinite compared to human skin