Why can a bird safely rest on a high-voltage power line? We discuss three effects that can lead to the development of voltages and currents in the bird's body. To explain the absence of electric shocks, we give numerical estimates of these voltages and currents obtained from the standard solution for the voltage along a two-wire transmission line.

1.
C. F.
Dalziel
, “
Reevaluation of lethal electric currents
,”
IEEE Trans. Ind. Gen. Appl.
4
,
467
476
(
1968
).
2.
C. F.
Dalziel
, “
Electric shock hazard
,”
IEEE Spectrum
9
,
41
50
(
1972
).
3.
R. W. P.
King
,
Transmission-line Theory
(
Dover Pub. Inc.
,
New York
,
1965
).
4.
S.
Ramo
and
J. R.
Whinnery
,
Fields and Waves in Modern Radio
, 2nd ed. (
John Wiley & Sons
,
New York
,
1953
).
5.
W. H.
Hayt
, Jr.
and
J. A.
Buck
,
Engineering Electromagnetics
, 6th ed. (
McGraw-Hill
,
New York
,
2000
).
6.
CRC Handbook of Chemistry and Physics, Internet Version 2005
, edited by
D. R.
Lide
(
CRC Press
,
Boca Raton, FL
,
2005
) <http://www.hbcpnetbase.com>.
7.
B. F. J.
Schonland
,
Atmospheric Electricity
, 2nd ed. (
John Wiley and Sons
,
New York
,
1953
).
8.
G.
Stix
, “
Working Hot: Life at 750 kV
,”
IEEE Spectrum
9
,
54
56
(
1988
).
9.
Transmission Line Reference Book
, 2nd ed., edited by
J. J.
LaForest
(
Electric Power Research Institute
,
Palo Alto, Ca
,
1982
).
10.
Electrical Transmission and Distribution Reference Book
, 4th ed., edited by
A. C.
Monteith
and
C. F.
Wagner
(
Westinghouse Electric Co.
,
Pittsburgh, Pa
,
1964
).
11.
C.
Gomes
, “
Lightning safety of animals
,”
Int. J. Biometeorol.
56
,
1011
1023
(
2012
).
12.
Z.
Bihua
,
R.
Heming
,
S.
Lihua
, and
G.
Cheng
, “
Calculation of step voltage near lightning current
,” in
IEEE Proceedings of Radio Science Conference
(
2004
), pp.
646
649
.
13.
T. T.
Bracken
,
G. G.
Sias
,
C.
Kim
,
R. S.
Senior
, and
R. M.
Patterson
, “
Survey of electrical utility worker body impedance
,”
IEEE Trans. Power Delivery
23
,
1251
1259
(
2008
).
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