A new study by the Bulgarian Society for the Protection of Birds (BSPB) shows a significant reduction in bird mortality after the electrification of power lines in the Burgas Lakes area. The report was prepared as part of the project Life safe grid for Burgas (LIFE20 NAT/BG/001234), implemented jointly with Elektrorazpredelenie Yug, and assesses the effectiveness of the insulation covers and diverters installed on 20 kV power lines, while also studying mortality on power lines that have not yet been made safe.
The secured sections include poles with added insulation coatings and overhead conductors with installed diverters. Between March and November 2025, 87 km of secured power lines (1,001 poles) were inspected, as well as a new 6 km section near the village of Zidarovo. A total of 50 dead birds of four species were found, all as a result of electric shock. No casualties from collisions with wires were recorded.
The most affected species remains the white stork (Ciconia ciconia) – 47 individuals. Other species found include the saker falcon(Falco cherrug), the long-eared owl (Asio otus), and the short-toed snake eagle (Circaetus gallicus).
The most dangerous area remains Bratovo-Ravnets-Dolno Ezerovo, located near the Burgas waste disposal site, where tens of thousands of storks gather. However, the data show a significant decline in mortality:
- 24.11 ind./km in 2022 (before safety measures were implemented)
- 9.33 ind./km in 2024
- 3.66 ind./km in 2025
This represents a reduction of over 80% compared to the initial values and demonstrates the high effectiveness of the insulation coatings installed. In the other secured areas, no casualties were reported in 2025, i.e. the effectiveness is 100%. В останалите обезопасени райони през 2025 г. не са установени жертви, т.е. ефективността е 100%.
The analysis shows that for the most common type of poles (Type 2), the installed insulation coatings are almost completely effective in preventing electric shock. Fatalities were mainly recorded on Type 1 and Type 6 steel lattice poles located directly next to the waste disposal site, where large groups of storks land at the same time.
During an inspection of a new 6-kilometer line near the village of Zidarovo, three victims were found, including a globally endangered peregrine falcon with a satellite transmitter. The line includes dangerous types of poles and has been recommended for priority safety measures.
The BSPB team identified new priority areas for the installation of insulating covers on the poles and the installation of diverters.
The study confirms that targeted safety measures for the electricity distribution network are an effective way to reduce bird mortality and have a direct positive effect on biodiversity conservation in the Burgas Lakes area. The effect on electricity consumers is also positive, with a significant reduction in emergency power cuts for EVN customers in the area.
