Eastern imperial eagle Aquila heliaca

Dispersal of eastern imperial eagles from the Czech Republic

“…Unfortunately, the final data from individual LX527 was sent in his second autumn, after which no more data were received. Our result of 12.5% migrating individuals in 1 st CY (two of 16) appears to be comparable with published data on tagged nestlings from Hungary and Austria, where just 12.3% of birds (seven of 57; Bragin et al 2021) performed long-distance movements to Greece (five ind. ), Syria (one ind.)…”

“…Birdlife International (2019) states that the species is a full migrant, though it is traditionally assessed as resident or partially migratory (Cramp & Simmons 1980, Keller et al 2020). While Huntley et al (2007) also classify the species as migratory, they described it as a partial migrant in Central Europe, with young and immature individuals moving south to the Mediterranean region (Cepák et al 2008, Bragin et al 2021), while adult territorial birds are mainly resident in Central and Southeastern Europe, spending winter in their breeding territories (Bagyura et al 2002, Stoychev et al 2004, Demerdzhiev et al 2011). Bragin et al (2021) states that the species is partially-migratory or non-migratory, breeding in forest-steppe regions of Eurasia and wintering in Northern Africa, the Middle East or South Asia, while Horváth et al (2018b) states that while the large eastern populations in Russia and Kazakhstan are migratory, the western populations in Central Europe, the Balkans, Anatolia and Caucasus are thought to be resident.…”

“…Eastern imperial eagles gain their final adult plumage after four or five annual moults, i.e. around the 6 th CY (Clark 2004, Bragin et al 2021). Nevertheless, the eagles regularly breed between the 3 rd and 5 th CY, before they obtain their dark brown adult plumage (Horváth et al 2014).…”

“…Eastern imperial eagles appear to have diverse migratory strategies with regard to age and origin (Bragin et al 2021); thus, their seasonal distribution may have to be studied on different levels, i.e. through indirect count data without individual recognition, uniquely tagged individuals with random resighting and/or individuals tracked by telemetry on a long-term basis (Thorup et al 2014).…”

“…The linkages between the northern breeding areas of eastern imperial eagles and their southern wintering areas are not well known (Bragin et al 2021). Further, there is a lack of data on stopover behaviour, daily distances travelled and the frequency and repeatability of migration journeys in juveniles, sub-adults and adults from different parts of its distribution range.…”