Ask A Scientist General Science Archive

Author:     ranger
Text:      Why is it that birds can sit on electric wires and not get shocked?

Response #:  1 of 1
Author:      Eric Peterson
Text:        For an electric current to flow, a complete path must exist.  In 
the case of birds on a wire, no path exists that is better (lower resistance) 
that the one that already exists.  Three conditions must exist if the "bird" 
were to get shocked:  
1 - There must be sufficient potential and electric current to overcome the 
body resistance of the bird (no problem there).
2 - There must be little or no insulation on the wire (sometimes no problem).
3 - The bird must simultaneously contact the bare wire and a conductor 
providing a path to ground (earth) or another conductor with a different 
electric potential (a second phase of AC current, for example).  Since most 
high wires are sufficiently Separated to prevent this type of thing from 
occurring, and they are also insulated both on their surface and on from the 
poles, it is unlikely that a bird will become a crispy critter.  It does 
happen though . . .