Power lines pose a threat to raptors

Thousands of kilometres long overhead power lines go through our country, transmitting electrical energy to customers. Birds have a liking for these power lines and often sit on electricity pylons or poles and power lines.

It is mainly in a land intensively used for agriculture, with monoculture fields and a lack of trees, in which poles provide a spot with sufficient view of the surroundings for raptors. On the electricity poles, they are waiting for prey or they simply just sit and rest.

However, for raptors the electricity poles carry a high risk of electrocution. A raptor can be seriously injured or it may die, if it simultaneously contacts two conductors or a conductor and a metal cross-arm with its wings. The bigger the raptor is, the higher is the risk of injury. Power lines going near a nest can be very dangerous. When flying for the first few times, young birds are not able to manoeuvre well, they tire easily and often sit on the first higher object they can see. And just in the middle of the monoculture fields, these are the electricity poles. Within the PannonEagle LIFE project, we took this issue into consideration during the inspections of nests of Eastern Imperial eagles. We checked with attention whether, amongst all the other factors having a negative impact on the breeding success, there was a power line near the nest. If that was the case, we documented the technical structure of the electricity poles (cross arm type, number and distribution of insulators, etc.) and addressed the energy companies. Thanks to the helpfulness of the companies Východoslovenská distribučná a.s. and Západoslovenská distribučná a.s., we managed to take mitigation measures on several high-risk lines. In addition to the power lines near nests, the energy companies took mitigation measures even on the lines, in the vicinity of which dead Eastern Imperial eagles had been found.

We have picked some of them for illustrative purposes.

Power line in the eastern Slovakia. Three power lines were in the immediate proximity to the nest. In the past, we have found remains of a dead Eastern Imperial eagle under the pole. Thanks to Východoslovenská distribučná, a.s. we managed to take mitigation measures here.

Remains of the dead Eastern Imperial eagle under the power line (photo: Jozef Chavko)

Three power lines near the nest (photo: archive RPS)

Power line in the western Slovakia. A random cyclist reported a dead Eastern Imperial eagle. A month later, another young eagle was found in the same spot by our member. After the arrangement with Západoslovenská distribučná, a.s., mitigation measures were taken so that no such death occurs again.

The dead Eastern Imperial eagle under the power line (photo: archive RPS)

Fitted insulation materials on the cross-arm of the pole (photo: archive RPS)