Red Eléctrica, the Redeia company responsible for the transmission and operation of the electricity system in Spain, is collaborating with the Government of Navarre to protect biodiversity in the Ribera region and, therefore, improve the integration of infrastructures in the local environment.

On this occasion, Red Eléctrica is promoting the protection of the golden eagle (Aquila Chrysaetos), a species found in Spain’s Red List of Birds, with the category of ‘almost under the threat of extinction’, through a programme of marking and radio-tracking of adult specimens.

The project has provided valuable information on the breeding area and the use of space in a number of territories occupied by golden eagles in la Ribera de Navarre. Radio-tracking has shown that golden eagles use electricity pylons for various purposes: as lookout points for hunting and surveillance, as shelters for resting and roosting, and as perches for consuming prey out of reach of other predators.

The choice of a specific pylon depends on its location and height as well as the eagles’ purpose for it, such as surveillance, hunting or roosting. Pylons located in good hunting areas or near peaceful roosting sites are often chosen. Their height is crucial, as they prefer to go for higher, 400 kV ones. In areas where towers vary in height, like the Castejón-Muruarte line, eagles tend to choose the tallest ones, often doubling the frequency of their perching on these high points.

This information on the golden eagle’s use of space in la Ribera de Navarre corresponds specifically to the areas of Caparroso-Marcilla, Cruchaga-Caparroso and Cadreita. The radio-monitoring programme is currently being run on three adult breeding golden eagles: "Luna", "Oskía" and "Keiles". 

The reproduction of radio-tracked eagle pairs is also being monitored, comparing their current reproductive parameters with those known for the same subpopulation decades ago and determining the extent of movements and their distribution in the three territories studied, comparing the habits of breeding pairs.

By comparing the pairs studied and their relationship with habitat types, it is hoped to draw conclusions that can be extrapolated to other golden eagle territories in Navarre. This will also help us understand the extent of their breeding areas, the dispersion of nesting sites in relation to the chosen habitat, and the overall habitat characteristics.
The project, which will conclude at the end of 2024, is making it possible to establish selection and environmental monitoring criteria for implementing new energy infrastructures to improve environmental management of the species in Navarre.