Movement of satellite-tracked juvenile saker falcons (Falco cherrug) in SW Slovakia

Abstract

During the period 2008-2011 nine juvenile saker falcon females from SW Slovakia were tracked with satellite telemetry. The movement of four of those females tagged with satellite tracking devices was analysed in 2011 (two juveniles for 6 months, one for 5 months and one for 3 months). The analysis of the collision risk with wind turbines also used telemetry data from previous years (2008-2009) - five birds tracked from abandoning their nest to abandoning their post-fledging areas (i.e. 45, 48, 37, 113 and 134 days). The juveniles visited 13 different countries during their post-fledging dispersal and migration. Maximum distance from the nest varied between 153 and 2094 km. For two birds the cause of death was recorded: one female was electrocuted and other female was probably also electrocuted. We also evaluated two factors of potential wind turbine threat: a) the distance of GPS locations from the nearest wind turbines in the vicinity of post-fledging areas, b) numbers ofwind turbines in post-fledging areas. Assessment of the collision risk with wind turbines showed low risk for the tracked individuals. Two of four tracked birds were at medium risk (2-5 km) from wind turbines. The highest risk for the young falcons comes from wind turbines in neighbouring countries, where they are constructed near borders.