DUGi

Impacte de les infraestructures elèctriques sobre l’avifauna a la Vall del Ridaura : avaluació de riscos i proposta de mesures correctores

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@26297

The Vall del Ridaura, between the municipalities of Santa Cristina de Aro, Castell-Platja d’Aro, Sant Feliu de Guíxols in the Baix Empordà region and Llagostera in the Gironès region, has its landscape modified by electrical infrastructures that often present an enormous danger for the birdlife present in this area. These birds can collide or be electrocuted by these structures if there are no measures to mitigate or eliminate this impact. The birds most affected by this problem are usually large birds such as birds of prey, gulls, Ciconiiformes or even birds linked to bodies of water. The aim of this study is to give a numerical value indicating the danger of each power line in order to propose corrective measures that go hand in hand with the danger and prioritize them according to the type of each support. During the months of January, February and March, a total of 816 electrical supports were sampled within the study area, looking for signs of electrocution (carcasses or animal remains) and categorizing support by support, geolocating and photographing them. On the other hand, it has been seen that the Vall del Ridaura is an area where, in general, the pylons are not isolated and do not have corrective measures and that many resources should be invested by the companies that manage these infrastructures to reduce the risk of electrocution on wild birds. Of the 52 lines sampled, 35 are considered non-dangerous while 17 would be dangerous. Translated into kilometers, almost 73 km of lines would have non-dangerous supports and 10.5 km of lines with dangerous supports. Finally, there was little evidence of electrocutions, only three, as many opportunistic mammals can take advantage of these below-line paths to forage for food without much effort. This is why a parallel and complementary study has been carried out to adjust this value, which is considered to be very biased from the real one, and to be able to estimate the time that passes between a bird being electrocuted and a scavenger foraging. A total of sixteen baits were placed under four power lines and it was found that after 6 days 94% of these baits had been depredated. In addition, a total of 5 photographic trapping cameras have been placed at different points to find out which animals are most prone to this opportunistic behavior

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