Status of the eastern imperial eagle population in Slovakia between 1977 and 2013

Abstract

Between 1 977 and 201 3 nesting of 72 different pairs of imperial eagle was recorded in Slovakia. The nesting population in Slovakia is concentrated in two subpopulations with the nesting area distant about 200 km. In Eastern Slovakia nesting of 42 pairs was recorded whilst in Western Slovakia 30 pairs were nesting. Authors present results of 37 years period of survey focused on distribution and trend of nesting population, as well as habitat preferences of the species. The paper compares results from Western and Eastern Slovakia. From Western Slovakia further data are evaluated, such as threats negatively influencing the population, period of hatching and other aspects of nesting biology. During the survey period the number of known nesting pairs in Slovakia has increased from five in 1 977 to 53 in 201 3. In total, 908 nesting events have been recorded during this period with 642 successful nesting events and 1 ,080 fledglings. In Western Slovakia the pairs prefer foothills, whilst in Eastern Slovakia most of the pairs nest in lowlands. Strong anthropic pressure is significantly influencing the distribution and size of the population as well as the habitat preferences of the species.

Breeding Population Structure of the Eastern Imperial Eagle

“…In several habitats, the breeding success of "atypical" pairs became higher than that of "typical" pairs, which determined the change in nesting patterns due to the greater production of free individuals by pairs nesting in open, poorly protected biotopes on deciduous trees in low relief elements or on the plain, but closer to food resource, and less by pairs, nesting covertly in well-protected biotopes on conifers growing on hills, but remote from the food resource (see . We see the same on the example of breeding groups of the Middle Danube population of the EIE in Slovakia (Chavko et al, 2014;Danko, Mihok, 2020) and Hungary Horváth et al, 2010;2011a;2020;Bagyura et al, скрытно в хорошо защищённых биотопах на хвойных деревьях, растущих на возвышенностях, но в удалении от кормового ресурса (см. Бекмансуров, 2015).…”

“…In East Slovakia, in 1971 some pairs nested on the same sites as in 1948-1957 (Svehlik, Meyburg, 1979). Since 1986 eagles began to colonize open farmland on plains (Danko, Chavko, 1996;Danko et al, 2011;Chavko et al, 2014). Two breeding groups remain in Slovakia by 2018 -west and east, wherein the east group nests only in the lowlands with losing mountainous nesting stereotype completely, while in the west group about 30% of pairs are still nesting in mountains Danko, Mihok, 2020).…”

“…Eagle's nesting was assumed in 1990 in southeast Slavonia near Yugoslavia (now Serbia) (Kralj, 1997), but since the beginning of the XXI century there hasn't been any current data from this country , and only the 1979). С 1986 г. орлы стали колонизировать открытые сельскохозяйственные угодья на равнине (Danko, Chavko, 1996;Danko et al, 2011;Chavko et al, 2014). К 2018 г. в Словакии как и в начале века сохраняется две гнездовых группировки -восточная и западная, при этом в восточной группировке вид гнездится теперь только в низменностях, а стереотип гнездования в горах полностью утерян, а в западной группировке около 30 % пар всё ещё гнездятся в горах (Хавко и др., Danko, Mihok, 2020).…”

“…Бекмансуров, 2015). То же самое мы видим на примере гнездовых группировок Среднедунайской популяции орла-могильника в Словакии (Chavko et al, 2014;Хавко и др., 2018;Danko, Mihok, 2020) и Венгрии Horváth et al, 2010;2011a;2020;Хорват и др., 2018;Bagyura et al, 2020). А повышение успеха размножения орлов в агроландшафтах, в отличие от гнёзд в «классических» местообитаниях на опушках крупных лесных массивов, показано на примере Харьковской области Украины (Витер, Толстяк, 2020).…”

Dispersal of eastern imperial eagles from the Czech Republic

“…Between 2000 and 2010, there was a sevenfold increase in the number of known eastern imperial eagle breeding pairs in Europe (Demerdzhiev et al 2011). The concurrent increase in the Czech breeding population is likely to have been, at least partly, part of the same positive population trend seen in Slovakia (Danko et al 2011, Chavko et al 2014 and Hungary (Bagyura et al 2002, the Hungarian population in particular increasing from six to 329 breeding pairs between 1980 and 2020 (Horváth 2022). Nevertheless, Bragin et al (2021) listed a series of factors still threatening the species, including electrocution, persecution and capture for sale, while Stoychev et al (2014Stoychev et al ( , 2018, alongside electrocution, also specified factors such as shooting, poisoning and collisions.…”