Avian electrocution mortality in relation to pole design and adjacent habitat in Spain

Abstract

Quantitative differences were assessed in avian mortality by electrocution between the most frequent pole designs and habitat types in south-west Spain. Pin-type insulators in natural habitats accounted for 36.9% of total avian mortality. Including all species, we estimated a mean annual death rate of 4.5 birds per 100 poles (95% confidence interval: 3.0-6.03), of which 53.8% were diurnal birds of prey. We identified all power poles in the distribution area of the Spanish Imperial Eagle Aquila adalberti population of the Doñana area. The estimated total mortality for adults was 0.38 birds per year and for immature eagles 3.38, which was 1.3% of the adult population and 30.0% of the mean annual number of fledged young. Adequate modification of 18.6% of power poles in the distribution area of the eagle population could reduce the total estimated mortality by 51.6%.