Thicken earth wire to reduce incidental bird mortality

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

0%
Certainty

42%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Removing earth wires is not always practical, given their protective nature. However, they can be rendered more visible by thickening the wire.

Key messages

A literature review found no evidence that thickening the earth wire had any impact on collision mortality of cranes Grus spp.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A literature review (Jenkins et al. 2010) describes how a paired site study in Colorado, USA (Brown et al. 1987), found that replacing 50% of the earth wire from 3.2 km of 115 kV wire with an earth wire three times thicker than normal had no effect on crane Grus spp. collision mortality compared to the span with a normal thickness earth wire.
Additional reference
Brown, W. M., Drewien, R. C. & Bizeau, E. G. (1987) Mortality of cranes and waterfowl from powerline collisions in the San Luis Valley, Colorado. 128–136 Proceedings of the crane workshop, 1985 Platte River Whooping Crane Maintenance Trust, Grand Island, Nebraska
Study and other actions tested
Referenced paper
Jenkins A., Smallie J. & Diamond M. (2010) Avian collisions with power lines: a global review of causes and mitigation with a South African perspective. Bird Conservation International, 20, 263-278.

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2020) Bird Conservation. Pages 137-281 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Bird Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Insulate power pylons to prevent electrocution Action Link	Likely to be beneficial	1	Synopsis Link
Thicken earth wire to reduce incidental bird mortality Action Link	Unknown effectiveness (limited evidence)	1	Synopsis Link
Add perches to electricity pylons to reduce electrocution Action Link	Unlikely to be beneficial	1	Synopsis Link