Bird injuries or fatalities due to electric shocks, as reported in the press in the case of overhead lines with lower voltages (up to 110 kV), cannot occur with extra-high-voltage overhead lines. 50Hertz supports a range of measures to facilitate improved bird protection.
Due to the greater insulator distance with the planned 380kV power lines, the possibility of birds suffering electrical shocks is excluded. Furthermore, conductor bundles composed of a number of conductors are employed. These are more easily recognised by birds compared with individual conductors. In addition, visual warning signs are placed on ground conductors at ecologically sensitive locations such as watercourse crossings or river valleys to improve bird protection, which significantly improves the visibility of these cables.
Conductor bundles (triple or quadruple) are easily spotted by birds. The single earth-wire, which protects the extra high voltage lines against lightning strokes and runs between the tower tops, is less visible to birds. To mitigate the danger, 50Hertz uses bird protection markers.
Between 2012 and 2016, 50Hertz took the opportunity to have the effectiveness of bird protection markers studied scientifically. The 2.4 kilometre line section selected for this purpose for the most part runs through the Oder-Niederung area, which is important for bird protection, and within a European bird protection area. In the scope of construction work on the extra high voltage transmission line between Vierraden and Krajnik near the German-Polish border, scientists were able to study the impact risk for birds on overhead lines during 2012/2013 before and after the installation of the spiral-shaped black-and-white bird protection markers. In 2016, the spiral markers were replaced by a second type of bird protection marker (bird clapper: black-and-white moving elements) on the same line section and the same study was repeated. The report presented by biologists Dr. Beate Kalz and Ralf Knerr concludes that the used bird protection markers significantly decrease the impact risk for birds of all sizes. The number of collision victims was 72 per cent lower after the installation of the bird protection markers. When both types of bird markers were compared, there were no significant differences. Another finding of the study: large birds do not appear to be more frequently in danger of colliding with an earth-wire than small birds. The study of Dr. Beate Kalz and Ralf Knerr (Kalz, B. / Knerr, R. (2017) Sonderuntersuchung zur Wirksamkeit von Vogelschutzmarkierungen) summarises the study results from all three research periods, i.e. 2012, 2013 and 2016, and replaces the version of 2016.
The construction of overhead lines creates new habitats. In some locations, the power lines run through woodlands, crossing them in forest aisles. From an ecological perspective, these forest aisles can be considered "life lines".
Within these forest aisles, varied biotopes and habitats for insects, reptiles, birds and mammals may develop which are often worthy of conservation. In these newly created habitats, plants requiring special conditions such as extensive cultivation and regular clearance of undergrowth can be found – like many of the native orchids. The diversity of plant and animal species in the surrounding woodlands and agricultural land is usually considerably lower.
Electricity pylons provide birds with additional breeding opportunities. In north-eastern Germany, osprey now breed more frequently on towers than in trees. Amongst other species, falcons and ravens now use Towers.