Protection from electrocution: securing power lines
Power lines kill thousands of birds in Switzerland every year. Simple measures can prevent electrocution.
To prevent the mass death of birds on power lines, conservationists argue that pylons must continue to be secured against earth faults and short circuits.
Hundreds of thousands of birds risk electrocution when resting on medium-voltage power lines, warned Johannes Enssle, the Baden-Württemberg state chairman of the Nature and Biodiversity Conservation Union Germany (NABU). Large birds in particular, such as storks, birds of prey, and owls, use the pylons of overhead lines for perching, sleeping, or as nesting sites. “In doing so, however, they risk bridging insulators on the lines or causing short circuits”, said Enssle.
A new study provides an overview of bird protection on power lines in the EU. Birds can die on lines through earth faults or short circuits at pylons, or through collisions with overhead lines. The data analysis by the bird protection organisation “Raptor Protection Slovakia” shows that all 27 EU member states are grappling with these hazards. However, there are very different legal requirements and technical solutions. For the study, the authors surveyed bird protection organisations in all EU member states, covering affected species, the legal situation, and the effectiveness of technical solutions. “The goal should be to make both new network expansion and existing lines across Europe bindingly bird-safe.
Among the pioneers in bird protection are the Netherlands, Luxembourg, and Sweden, where underground cables are used. “That is certainly the best solution”, says NABU state chairman Enssle. “It is expensive, but it is the trend, especially for new construction.”
According to a study commissioned by NABU and based on data from bird protection organisations, white storks and common buzzards are most frequently killed by electric shocks in Germany — despite a legal obligation to make dangerous pylons safe. Eastern imperial eagles and saker falcons in Eastern Europe were said to be threatened in their populations by unsecured electricity pylons, as noted at the study’s publication at the end of June. Collisions with lines, according to NABU, kill particularly large numbers of swans as well as other waterfowl and large birds.
The Federal Nature Conservation Act already stipulates that medium-voltage power line pylons must be retrofitted. However, no deadline is set, and previous retrofits on many power pylons have proven ineffective.
Bird flight diverters attached to the lines can make them visible to animals as well. This could prevent a large proportion of the particularly numerous collisions.
Exact figures on the dead birds – including storks, red kites, and eagle owls – are not available. The number of unreported cases is enormously high, said Enssle. "Most electrocution victims fall from the pylon and, if not already killed by the electric shock, are seriously to fatally injured by the fall." In the most recent NABU study, conservationists estimate at least 1.5 million birds killed per year on pylons and power lines.
