Overhead lines in areas with sensitive populations of large birds raise demands for protection against bird electrocution (mortal current transfer through the bird bodies), particularly for threatened species like the eagle owl. For the decision making of what protection measures to apply, it is important to assess both their environmental benefits and the measures of technical consequences. One of the popular retrofit protection methods is insulation of the aluminium conductors at pin insulated medium voltage overhead line poles. In the present work, we have performed accelerated corrosion tests on aluminium conductors using four different bird protection systems available on the market. The tests were performed in laboratory environment for marine corrosivity indices 4 and 8, and simulated time periods up to 24 years. The results show that the systems influence the degradation of the aluminium conductors, leading to life-time expectancy reductions between 12 and 22% for the investigated corrosivity indices. Copyright © 2013 John Wiley & Sons, Ltd.