The summary on raptors and owls ringing in Slovakia in 2009
The article provides basic information about the number, species and recoveries of ringed birds of prey and owl species in Slovakia in 2009. The report follows similar papers from the following periods: 2002-2004, 2005-2006 and 2007-2008. In 2009 a total of 1,222 individuals were ringed in Slovakia, of which 856 individuals were birds of prey (18 species) and 366 individuals were owls (8 species). From the total number, 719 birds of prey and 257 owl nestlings were ringed. In comparison with the previous year the number of ringed birds of prey and owls increased by 43%.
Summary on the ringing of raptors and owls in Slovakia in 2010
This paper presents brief information on the number, species and recoveries of ringed birds of prey and owls in Slovakia in 2010. It follows similar papers from 2002-2004, 2005-2006, 2007-2008 and 2009. In 2010 a total of 552 individual birds of prey and owls were ringed in Slovakia, of which 405 were birds of prey (16 species) and 147 owls (9 species). From the total number ringed, 327 birds of prey and 85 owl were nestlings. In comparison with the previous year (2009) the number of ringed birds decreased by 55%.
Vladimír Slobodník, Roman Slobodník and Miroslav Dravecký
Summary on raptors and owls ringing in Slovakia in 2007 and 2008
This article provides brief information about the number, species and reports about ringed raptors and owls in Slovakia during the period 2007-2008. It is a continuation of similar results of the ringing of raptors and owls in the periods 2002-2004, 2005-2006. In 2007, from 1346 individuals of raptorial birds, 941 raptors and 405 owls of 24 species (16 species of raptors and 8 species of owls) including 805 raptors' and 218 owls' nestlings were ringed. In 2008, a total of 856 individuals were ringed, including 542 raptors and 314 owls of 25 species (15 species of raptors and 10 species of owls) including 421 raptors' and 113 owls' nestlings. Also in 2008, the number of ringed raptors and owls decreased by 36.4% in comparison to 2007.
The red-footed falcon (Falco vespertinus) migrates throughout the territory of Slovakia regularly, though it rarely breeds here. In the present paper we have reviewed and summarised its observations between the years 1905–2016, focusing on the spring and autumn migration periods and its occurrence outside the breeding season. In total, we have gathered the data on 799 observations of 3,717 individuals. Considering the unsystematic data collection, the data should be taken with caution and may rather serve for information purposes only. However, they provide useful basic items of information regarding the species’ seasonal dynamics in Slovakia and its phenology, and document the evident increase in the number of individuals observed since 2014.
The article provides basic information about the number, species and recoveries of ringed birds of prey and owl species in Slovakia in 2011 . The report follows similar papers from the following periods: 2002-2004, 2005-2006, 2007-2008, 2009 and 201 0. In 2011 a total of 61 0 individuals were ringed in Slovakia, of which 509 individuals were birds of prey (1 6 species) and 1 01 individuals were owls (9 species). From the total number, 426 raptor nestlings and 46 owl nestlings were ringed. In comparison with the previous year 201 0 the number of ringed birds of prey and owls increased by 11%.
The Ural owl (Strix uralensis) is considered to be a habitat specialist preferring structurally heterogeneous old montane forests in Central Europe. Unlike the sympatric tawny owl (Strix aluco), the Ural owl is negatively affected by human activities in its forest habitats and usually avoids human settlements. Although the young birds and wintering adults show no strong dependence on the size of forest patches and their structure, there are only a few studies on the occurrence of this owl species in non-forest and urban habitats. Here we describe several observations of wintering Ural owls in south-eastern and south-western Slovakia outside the forests during the winter 2017/2018. The Ural owls were recorded in agricultural country, but not infrequently also in human settlements.
Filip Tulis, Imrich Jakab, Roman Slobodník and Michal Hudec
During the years 2010-2012, we observed the spatial activity of long-eared owls by the radio telemetry in an agricultural land. The average home range size of tracked long-eared owls for 100 and 95% minimum convex polygon (MCP) was 415.93 and 350 ha, respectively. Between the breeding and the non-breeding season, we did not record significant differences in the size of home ranges. Open land units (meadows and arable lands) belonged to the most abundant land units in the home ranges of tracked owls (mean for 100 and 95% MCP was 24.6 and 24.3%, respectively). Forest edges with their ecotone character also represented the abundant land unit (mean for 100 and 95% MCP was 11.4 and 10.6%, respectively). An amount of built-inhabited areas in home ranges (mean for 100 and 95% MCP was 8.2 and 10.1%, respectively) correlated positively with their size (Spearman rank correlation: for 100% MCP: rs = 0.83, p <0.05; for 95% MCP: rs = 0.91, p <0.05) that indicates long-eared owls to be avoiding built-inhabited areas as an area of the food getting. Two individuals of long-eared owl changed the winter roosts during one non-breeding season, which were at a distance of 650 m from each other.
Jozef Chavko, Ján Obuch, Ján Lipták, Roman Slobodník and Michal Baláž
In the period between the years 1976 to 2016 we monitored the nesting site distribution of two populations of saker falcon (Falco cherrug) concentrated in the highlands and adjacent lowlands of western and eastern Slovakia. In western Slovakia we recorded nesting by 56 pairs and 514 nestings, and in eastern Slovakia we observed nesting by 32 pairs and 245 nestings. There were similar nesting success rates in both regions, with pairs producing on average 3.2 young in every successful nest. During the monitored period as a whole a total of 1,788 young saker falcons were raised. At the same time all the pairs gradually resettled in the lowlands, and in the new environment the nesting success rate significantly improved (81.1% compared with 57.1 % in the highlands). This change of nesting biotopes was caused by the impacts of intensive exploitation and environmentally inappropriate forest management, with the accompanying excessive disturbance of nesting birds, but at the same time the disappearance of ground squirrel (Spermophilus citellus) colonies led to a change in the food spectrum for the observed saker falcon pairs. We evaluated the falcons’ feeding habits in western Slovakia between the years 1977 and 2016 (49 pairs; 1–17 pairs/year) and in eastern Slovakia between 2009 and 2016 (12 pairs; 1–3 pairs/year). Altogether 17,669 prey items were identified. From 1976 onwards mammals (Mammalia, 19.8%, 24 species) became gradually less represented as a component in the falcons’ diet compared with birds (Aves, 79.9%, 58 species). In areas of western Slovakia we found stable and predominant proportions of domestic pigeons (Columba livia f. domestica) ranging from 52% to 62%. The proportion of pigeons was distinctly lower in eastern Slovakia (31.5%), compensated for by larger shares of common vole (Microtus arvalis), common starling (Sturnus vulgaris), Eurasian magpie (Pica pica) and hooded crow (Corvus cornix). The common starling (9.5%) was a significant prey species in the lowlands of western and eastern Slovakia alike. Mammals were mostly represented by common voles (9.8%), European hamsters (Cricetus cricetus, 5.3%), ground squirrels (2.1%) and hares (Lepus europaeus, 1.6%). Changes over time in the composition of falcons’ prey were also evaluated over five periods in western Slovakia.
Roman Slobodník, Jozef Chavko, Jozef Lengyel, Michal Noga, Boris Maderič and Michal Baláž
The population of the red-footed falcon in Slovakia inhabits the north-western edge of the species' breeding range. This breeding population is relatively small and came near to extinction during the population decline of this species in central Europe in recent decades. Thanks to increasing numbers of breeding pairs in Hungary, the Slovak population began to grow again. Moreover, some differences in breeding biology associated with breeding in nest boxes were found. Here we describe the dependence of the small isolated breeding population in Slovakia on the core population in the more eastern parts of the Carpathian Basin, and the impact of supporting activities (nest boxes) on this raptor species in Slovakia.
Roman Slobodník, Filip Tulis, Jozef Chavko and Jozef Lengyel
The rook is a species inhabiting open agricultural landscape whose non-active nests are also used by other bird species for nesting. It is the decline in rook colonies that has been posited as one of the reasons for decrease in the red-footed falcon (Falco vespertinus) population in Slovakia since the 1970s. During the period from 2012 till 2016, four monitorings of rook colonies were carried out in south-western Slovakia (Diakovce, Nitrianska Osada, Sokolce and Tvrdošovce). In the colony at Tvrdošovce, supporting activity involving provisioning of rooks with nest material was under way from 2014 until 2016. While the colonies at Diakovce and Nitrianska Osada have been showing a slight decrease in the number of nesting rooks, despite larger interannual differences the colony at Sokolce has been showing an upward trend. The size of the colony at Tvrdošovce has been stable since the beginning of the supporting activity. This activity had a statistically significant positive effect on the width of rook nests. In 74 cases in the studied rook colonies we have recorded nesting by three other bird species – Eurasian kestrel (Falco tinnunculus) 43.8%, western jackdaw (Corvus monedula) 39.7% and long-eared owl (Asio otus) 16.4%. In 2015 two female redfooted falcons were observed in the colony at Tvrdošovce.