First Year Dispersion of White-tailed Sea Eagles from Central Europe, Based on GPS/GSM Telemetry

Abstract

Austria, Czech Republic and Hungary are located in central Europe, where the white-tailed sea eagle Haliaeetus albicilla (WTSEs) was one of the most frequent large raptor species during the 19th century, with substantial numbers of breeding pairs and wintering individuals. Due to landscape changes, direct persecution and intensified agriculture the population decreased dramatically in the 20th century. The species completely disappeared as a breeder from Czech Republic since at least 1920s until 1970s or even 1980s (Bělka, Horal, 2009) as well as from Austria since 1960s until the late 1990s (Probst, Peter, 2009; Probst, 2009). In Hungary, population of this once a widespread breeder (in 19th century) continually decreased until 1970s when a population minimum of ca 20 breeding pairs was reached, most of them in southern Danube valley (Bank et al., 2004). Later on, the breeding population began to recover slowly and now the breeding population consists from 35 territorial pairs (30 breeding) in Austria in 2017 (Probst, Pichler, 2017), 116 known breeding pairs in Czech Republic in 2016 (Bělka, 2017) and 279–307 breeding (egg-laying) pairs in Hungary in 2016 (Szelényi, 2016). It seems that WTSEs from Germany and Poland predominated in recolonization of the population in the western and northern part of the Czech Republic, and that the core Danube population was predominant in the recolonization of southeastern part of the Czech Republic and eastern Austria and Hungary. Moreover, ringing data and recent genetic studies suggest that WTSE populations in central Europe may even have been reestablished by eagles from North European populations (Literák et al., 2007, Nemesházi et al., 2016). Because there are only limited data about a dispersion of WTSEs from this recovered Central European population based on ringing data and because GPS/GSM telemetry is much more powerful tool for spatio-temporal studies than ringing activities, the aim of our study was to reveal the first year dispersion of WTE from central Europe using GPS/GSM telemetry.

Keywords

• birds of prey
• white-tailed sea eagle
• haliaeetus albicilla