Quantitative differences were assessed in avian mortality by electrocution between the most frequent pole designs andhabitat 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 SpanishImperial Eagle Aquila adalberti population of the DoÃana area. The estimated total mortality for adults was 0.38 birdsper year and for immature eagles 3.38, which was 1.3% of the adult population and 30.0% of the mean annual numberof fledged young. Adequate modification of 18.6% of power poles in the distribution area of the eagle populationcould reduce the total estimated mortality by 51.6%.

Olrog's Gull Larus atlanticus is an endemic species of the Atlantic coast of southern South America. It is one of six globally threatened gull species in the world, and is classified as Vulnerable. We studied age-related differences in the diet and foraging behaviour of this species in Mar Chiquita Lagoon during the non-breeding season. Diet was assessed by analysis of regurgitation casts, prey carcasses and direct observation, while foraging behaviour was quantified by focal observations. Grapsid crabs were by far the main prey in frequency of occurrence, followed by fish and snails. Some differences in diet were found between ages, particularly in spring when mature birds start to feed on the eggs of ovigerous females of the crab Cyrtograpsus angulatus. Foraging behaviour was similar between ages which is attributed to large resource availability, foraging strategies and social factors.




Russian Mature Tgp