Birds like to have a good view and use overhead lines as places to land and gather. They do so as a matter of course, naturally without any knowledge of electric potential differences and electrical circuits. Because as long as they only touch one line, there is no risk for them, as the circuit is not closed.
Every year, about 10,000 birds suffer fatal electric shocks; birds with a larger wingspan are most likely to be affected. They receive a dangerous electric shock if they simultaneously touch another line or the earthed pylon. To avoid this, protection measures have been drawn up under Article 53 of the Federal Nature Conservation Act. This calls upon electric utilities to convert their pylons to prevent electric shocks. The technical experts in the standardization bodies are needed to help formulate these protective measures. They have developed protective caps, for example, to enclose the cables near to the pylons in an effort at least to prevent short-circuits to earth.