Re: Why do birds that perch on telephone poles not get electrocuted?

Dear Jennifer:

The reason why birds do not get electricuted on telephone poles or wires 
is very simple: They do not make a completed circuit.  The bird is only 
resting on one of the lines that has power flowing through it. There is no 
current flow because there is no difference in the voltage or potential.

If the bird was to contact two different wires (or the wire and the 
ground), there would be a voltage difference and the current would flow 
through the bird.  This would result in an electrocuted bird!  This does 
happen on occasion - usually when a large owl, hawk or eagle is trying to 
fly through high power lines and contacts two wires at once.  It can also 
occur when a large bird (such as an eagle) sits on top of a telephone pole 
and contacts two different wires with its feet.

This is also the reason why squirrels can be seen running along power 
lines.  Same answer - the squirrel is only in contact with one line at a 
time.

James Powell