Abstract The article deals with trends in the Eurasian eagle-owl (Bubo bubo) population in Czechia and the interplay between legal regulation of hunting and nature protection. In the early 20th century, the eagle-owl population in Bohemia decreased to an estimated 20 nesting pairs, and the population in Moravia and Silesia was subsequently estimated to be similarly low. In previous centuries, eagle-owls had been persecuted as pest animals; additionally, their chicks were picked from nests to be kept by hunters for the eagle-owl lure hunting method (“výrovka” in Czech), where they were used as live bait to attract corvids and birds of prey, which were subsequently killed by shooting. As soon as the state of the eagle-owl population was established in the 1900s, the effort to save the autochthonous eagle-owl population commenced. Nevertheless, when eagle-owls became legally protected from killing in the 1930s, the eagle-owl lure hunting method was not prohibited. The intensified use of this hunting method in the 1950s was accompanied by serious decline in the populations of birds of prey in the Czech countryside, when tens of thousands of Eurasian sparrowhawks (Accipiter nisus), northern goshawks (Accipiter gentilis), common buzzards (Buteo buteo) and rough-legged buzzards (B. lagopus) were killed on a yearly basis. The usage of eagle-owl chicks in lure hunting was criticised by ornithologists concerned with the conservation of birds of prey. The eagle-owl thus became a subject of more general debate on the role of predators in nature, and this debate (albeit regarding other predator species) has continued to the present-day. As the eagle-owl population has been growing steadily following the prohibition of its killing in the 1930s, its story may serve as an example of the need for effective legal protection of predators to ensure their survival in the intensively exploited central-European environment. The article examines the successful preserving of the eagle-owl in the Czech countryside, from its low point in the early 20th century towards today’s stable and ever-increasing population, focusing on environmental, conservationist, legal and societal aspects of the issue.
{"title":"Changes in the Eurasian eagle-owl (Bubo bubo) population in Czechia and their association with legal protection","authors":"Jan Andreska, Dominik Andreska","doi":"10.2478/srj-2020-0003","DOIUrl":"https://doi.org/10.2478/srj-2020-0003","url":null,"abstract":"Abstract The article deals with trends in the Eurasian eagle-owl (Bubo bubo) population in Czechia and the interplay between legal regulation of hunting and nature protection. In the early 20th century, the eagle-owl population in Bohemia decreased to an estimated 20 nesting pairs, and the population in Moravia and Silesia was subsequently estimated to be similarly low. In previous centuries, eagle-owls had been persecuted as pest animals; additionally, their chicks were picked from nests to be kept by hunters for the eagle-owl lure hunting method (“výrovka” in Czech), where they were used as live bait to attract corvids and birds of prey, which were subsequently killed by shooting. As soon as the state of the eagle-owl population was established in the 1900s, the effort to save the autochthonous eagle-owl population commenced. Nevertheless, when eagle-owls became legally protected from killing in the 1930s, the eagle-owl lure hunting method was not prohibited. The intensified use of this hunting method in the 1950s was accompanied by serious decline in the populations of birds of prey in the Czech countryside, when tens of thousands of Eurasian sparrowhawks (Accipiter nisus), northern goshawks (Accipiter gentilis), common buzzards (Buteo buteo) and rough-legged buzzards (B. lagopus) were killed on a yearly basis. The usage of eagle-owl chicks in lure hunting was criticised by ornithologists concerned with the conservation of birds of prey. The eagle-owl thus became a subject of more general debate on the role of predators in nature, and this debate (albeit regarding other predator species) has continued to the present-day. As the eagle-owl population has been growing steadily following the prohibition of its killing in the 1930s, its story may serve as an example of the need for effective legal protection of predators to ensure their survival in the intensively exploited central-European environment. The article examines the successful preserving of the eagle-owl in the Czech countryside, from its low point in the early 20th century towards today’s stable and ever-increasing population, focusing on environmental, conservationist, legal and societal aspects of the issue.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85448255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A sample of 73 dry, well-preserved skulls was studied, representing various species of raptors with different foraging strategies. The sample included Accipiter nisus (n = 15), Buteo buteo (n = 13), Gyps fulvus (n = 24) and Neophron percnopterus (n = 5), Bubo bubo (n = 16) and Tyto alba (n = 2). Geometric morphometric methods were used to detect orbital asymmetries. On digital pictures of each skull side, a set of 16 semi-landmarks and two landmarks were located in order to describe the orbital ring. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed that the orbital asymmetry of raptors differed significatively between species, although directional asymmetry (e.g. left orbita systematically more developed than the right) appeared not to be correlated with orbital size. This indicates that larger orbitas do not lead to greater asymmetry. Differences between species should rather be explained by their foraging strategies and degree of visual obstruction in their natural environment.
{"title":"Comparison of orbital asymmetries among some raptor species: “when size does not matter”","authors":"P. Parés-Casanova, Jordina Salas-Bosch","doi":"10.2478/srj-2020-0005","DOIUrl":"https://doi.org/10.2478/srj-2020-0005","url":null,"abstract":"Abstract A sample of 73 dry, well-preserved skulls was studied, representing various species of raptors with different foraging strategies. The sample included Accipiter nisus (n = 15), Buteo buteo (n = 13), Gyps fulvus (n = 24) and Neophron percnopterus (n = 5), Bubo bubo (n = 16) and Tyto alba (n = 2). Geometric morphometric methods were used to detect orbital asymmetries. On digital pictures of each skull side, a set of 16 semi-landmarks and two landmarks were located in order to describe the orbital ring. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed that the orbital asymmetry of raptors differed significatively between species, although directional asymmetry (e.g. left orbita systematically more developed than the right) appeared not to be correlated with orbital size. This indicates that larger orbitas do not lead to greater asymmetry. Differences between species should rather be explained by their foraging strategies and degree of visual obstruction in their natural environment.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79428835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Between 2012 and 2019, 6523 raptors and owls (30 species) were ringed in Slovakia. The most abundant was the common kestrel (2811 individuals), then the western marsh harrier (664) and saker falcon (517). The proportion of nestlings among all the ringed individuals was 84.4%. In the given period, 340 recoveries of raptors and owls (23 species) were recorded in the ringing station database. This number included 160 recoveries of individuals colour-marked and also recovered in our territory. There were 83 recoveries of birds ringed in Slovakia and resighted abroad. The last 97 recoveries were of individuals ringed abroad and recovered in Slovakia. In summary, most of the recoveries (of all types) were of Eastern imperial eagle (62 recoveries), then red-footed falcon (51) and common kestrel (43). Most of the recovery circumstances were ring reading (44% in total), recaptures (15%) and findings of bird cadavers. Regarding raptors or owls, collisions with vehicles (5%) and electrocutions (5%) were frequent causes of their deaths.
{"title":"Summary of raptor and owl ringing in Slovakia in the period from 2012 to 2019","authors":"Roman Slobodník, Michal Jenčo","doi":"10.2478/srj-2020-0007","DOIUrl":"https://doi.org/10.2478/srj-2020-0007","url":null,"abstract":"Abstract Between 2012 and 2019, 6523 raptors and owls (30 species) were ringed in Slovakia. The most abundant was the common kestrel (2811 individuals), then the western marsh harrier (664) and saker falcon (517). The proportion of nestlings among all the ringed individuals was 84.4%. In the given period, 340 recoveries of raptors and owls (23 species) were recorded in the ringing station database. This number included 160 recoveries of individuals colour-marked and also recovered in our territory. There were 83 recoveries of birds ringed in Slovakia and resighted abroad. The last 97 recoveries were of individuals ringed abroad and recovered in Slovakia. In summary, most of the recoveries (of all types) were of Eastern imperial eagle (62 recoveries), then red-footed falcon (51) and common kestrel (43). Most of the recovery circumstances were ring reading (44% in total), recaptures (15%) and findings of bird cadavers. Regarding raptors or owls, collisions with vehicles (5%) and electrocutions (5%) were frequent causes of their deaths.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88133828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karol Šotnár, J. Obuch, Samuel Pačenovský, B. Jarčuška
Abstract Knowledge about spatial distribution of owl species is important for inferring species coexistence mechanisms. In the present study, we explore spatial patterns of distribution and habitat selection of four owl species u Eurasian pygmy owl (Glaucidium passerinum), boreal owl (Aegolius funereus), tawny owl (Strix aluco) and Ural owl (Strix uralensis) u ranging in body mass from 50 g to 1300 g, with sympatric occurrence in temperate continuous montane forests in the Veľká Fatra Mts., Western Carpathians, central Slovakia. Locations of hooting owl males were surveyed between 2009–2015 in an area of 317 km2. Spatial point pattern analysis was used for analysis of owl distribution. Random patterns of owls’ spatial arrangement dominate at both intra- and interspecific levels within the studied area. Only intraspecific distribution of pygmy owls and interspecific distribution of Ural owls toward tawny owls exhibited positive associations. This discrepancy with other studies can be explained in terms of pygmy owlsy preference for high-quality nest sites and/or spatial clustering in their prey distribution, and due to aggressive behaviour of dominant Ural owls toward subdominant tawny owls, respectively. Moreover, we found considerable overlap in habitat preferences between owl species, considering stand age, stand height, tree species richness, distance to open area, elevation, slope, percentage of coniferous tree species and position on hillslope, although pygmy owls were not registered in pure broadleaved stands, Ural owls were not registered in pure coniferous stands, and boreal and Ural owls were more common on slope summits and shoulders than tawny and pygmy owls. The observed patterns of spatial arrangement might suggest developed coexistence mechanisms in these owl species; differences between studies may indicate complex interactions between intra- and interspecific associations and habitat quality and quantity, food availability and owl species involved in those interactions on a landscape scale.
{"title":"Spatial distribution of four sympatric owl species in Carpathian montane forests","authors":"Karol Šotnár, J. Obuch, Samuel Pačenovský, B. Jarčuška","doi":"10.2478/srj-2020-0002","DOIUrl":"https://doi.org/10.2478/srj-2020-0002","url":null,"abstract":"Abstract Knowledge about spatial distribution of owl species is important for inferring species coexistence mechanisms. In the present study, we explore spatial patterns of distribution and habitat selection of four owl species u Eurasian pygmy owl (Glaucidium passerinum), boreal owl (Aegolius funereus), tawny owl (Strix aluco) and Ural owl (Strix uralensis) u ranging in body mass from 50 g to 1300 g, with sympatric occurrence in temperate continuous montane forests in the Veľká Fatra Mts., Western Carpathians, central Slovakia. Locations of hooting owl males were surveyed between 2009–2015 in an area of 317 km2. Spatial point pattern analysis was used for analysis of owl distribution. Random patterns of owls’ spatial arrangement dominate at both intra- and interspecific levels within the studied area. Only intraspecific distribution of pygmy owls and interspecific distribution of Ural owls toward tawny owls exhibited positive associations. This discrepancy with other studies can be explained in terms of pygmy owlsy preference for high-quality nest sites and/or spatial clustering in their prey distribution, and due to aggressive behaviour of dominant Ural owls toward subdominant tawny owls, respectively. Moreover, we found considerable overlap in habitat preferences between owl species, considering stand age, stand height, tree species richness, distance to open area, elevation, slope, percentage of coniferous tree species and position on hillslope, although pygmy owls were not registered in pure broadleaved stands, Ural owls were not registered in pure coniferous stands, and boreal and Ural owls were more common on slope summits and shoulders than tawny and pygmy owls. The observed patterns of spatial arrangement might suggest developed coexistence mechanisms in these owl species; differences between studies may indicate complex interactions between intra- and interspecific associations and habitat quality and quantity, food availability and owl species involved in those interactions on a landscape scale.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89812670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The classic ornithological work by Félix de Azara “Apuntamientos para la historia natural de los páxaros del Paraguay y Rio de la Plata” was one of the first descriptive texts dealing with the avifauna of the Southern Cone of South America. Azarays No. 18 vGavilán mixto pintadow has long been misidentified as a juvenile great black hawk (Buteogallus urubitinga ((Gmelin, 1788)). However, there are clear inconsistencies in the description of the plumage coloration, shape and measurements which make that identification erroneous, and Azarays No. 18 can in fact be convincingly identified as the juvenile plumage of the Harrisys hawk (Parabuteo unicinctus (Temminck, 1824)). The description by Azara contains numerous diagnostic characteristics for that species, and the measurements provided by him are inconsistent with those of the great black hawk, yet remarkably similar to those provided by the same author for the description of the adult No. 19 vGavilán mixto obscuro y canelaw. No scientific names have apparently ever been based on Azara No. 18.
f lix de Azara的经典鸟类学著作《Apuntamientos para la historia natural de los páxaros del Paraguay y里约热内卢de la Plata》是最早描述南美洲南锥体鸟类的文献之一。Azarays No. 18 vGavilán mixto pintadow一直被误认为是幼年大黑鹰(Buteogallus urubitinga ((Gmelin, 1788))。然而，在羽毛颜色、形状和尺寸的描述中存在明显的不一致，这使得这种鉴定是错误的，事实上，Azarays No. 18可以令人信服地确定为Harrisys鹰的幼年羽毛(Parabuteo unicinctus (Temminck, 1824))。Azara的描述包含了该物种的许多诊断特征，他提供的测量值与大黑鹰的测量值不一致，但与同一作者提供的对成年No. 19 vGavilán mixto obscuro y canelaw的描述非常相似。显然没有任何科学名称是基于Azara 18号的。
{"title":"The identity of Azara’s description No. 18 “Gavilán mixto pintado” is a juvenile Harris’s hawk (Parabuteo unicinctus)","authors":"Paul A. Smith","doi":"10.2478/srj-2020-0001","DOIUrl":"https://doi.org/10.2478/srj-2020-0001","url":null,"abstract":"Abstract The classic ornithological work by Félix de Azara “Apuntamientos para la historia natural de los páxaros del Paraguay y Rio de la Plata” was one of the first descriptive texts dealing with the avifauna of the Southern Cone of South America. Azarays No. 18 vGavilán mixto pintadow has long been misidentified as a juvenile great black hawk (Buteogallus urubitinga ((Gmelin, 1788)). However, there are clear inconsistencies in the description of the plumage coloration, shape and measurements which make that identification erroneous, and Azarays No. 18 can in fact be convincingly identified as the juvenile plumage of the Harrisys hawk (Parabuteo unicinctus (Temminck, 1824)). The description by Azara contains numerous diagnostic characteristics for that species, and the measurements provided by him are inconsistent with those of the great black hawk, yet remarkably similar to those provided by the same author for the description of the adult No. 19 vGavilán mixto obscuro y canelaw. No scientific names have apparently ever been based on Azara No. 18.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75886676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Chavko, J. Obuch, J. Lipták, Roman Slobodník, M. Baláž
Abstract 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.
{"title":"Changes in nesting habitat of the saker falcon (Falco cherrug) influenced its diet composition and potentially threatened its population in Slovakia in the years 1976–2016","authors":"J. Chavko, J. Obuch, J. Lipták, Roman Slobodník, M. Baláž","doi":"10.2478/srj-2019-0009","DOIUrl":"https://doi.org/10.2478/srj-2019-0009","url":null,"abstract":"Abstract 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.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84875791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In winter 2013/2014 a roost of long-eared owls in Bojnice Spa (central Slovakia) was formed by two subgroups situated 12 meters apart from each other. The diets of both subgroups and the direction of the owls’ departure from the roost were studied at monthly intervals. Owls of the Pinus-subgroup left the roost in a significantly different direction compared with the owls in the Picea-subgroup. The common vole was the most hunted prey in both subgroups. However, comparing the alternative prey of the two subgroups, the wood mouse and other mammals were found significantly more often in pellets of the Picea-sub-group, whereas birds were more frequent in pellets of the Pinus-subgroup. Our results suggest that the different prey hunted by the two subgroups may be a consequence of diverging hunting areas with different availability of alternative prey species.
{"title":"Different alternative diets within two subgroups in a winter roost of long-eared owls","authors":"Filip Tulis, T. Veselovský, S. Birrer","doi":"10.2478/srj-2019-0002","DOIUrl":"https://doi.org/10.2478/srj-2019-0002","url":null,"abstract":"Abstract In winter 2013/2014 a roost of long-eared owls in Bojnice Spa (central Slovakia) was formed by two subgroups situated 12 meters apart from each other. The diets of both subgroups and the direction of the owls’ departure from the roost were studied at monthly intervals. Owls of the Pinus-subgroup left the roost in a significantly different direction compared with the owls in the Picea-subgroup. The common vole was the most hunted prey in both subgroups. However, comparing the alternative prey of the two subgroups, the wood mouse and other mammals were found significantly more often in pellets of the Picea-sub-group, whereas birds were more frequent in pellets of the Pinus-subgroup. Our results suggest that the different prey hunted by the two subgroups may be a consequence of diverging hunting areas with different availability of alternative prey species.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90318817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In 2015–2016, 6,429 km medium-voltage power lines with 76,430 pylons were checked for bird mortality in the Czech Republic. 1,326 bird victims of power lines were found, 156 of which died after collisions, and 1,170 birds were electrocuted. They belonged to 60 species from 12 orders, and birds of prey made up almost half of all victims. Steel pylons bearing several cross-arms including upper and crosswise jumpers were identified as most dangerous from the electrocution point of view. On the other hand, pylons in straight lines with Pařát cross-arms (triangular arrangement of conductors without any horizontal bar) were among the least dangerous, and when they had a simple perch fitted below the cross-arm, no mortality was recorded. But these pylons are new in practice and despite becoming widely used recently, they form less than one tenth of all pylons in the Czech Republic. On other pylons various types of mitigation measures have been installed. Commonly used plastic covers and plastic strips have proved to be especially effective, but only in cases when they are undamaged and correctly installed.
{"title":"Bird mortality on medium-voltage power lines in the Czech Republic","authors":"Vlasta Škorpíková, Václav Hlaváč, Milan Krapek","doi":"10.2478/srj-2019-0007","DOIUrl":"https://doi.org/10.2478/srj-2019-0007","url":null,"abstract":"Abstract In 2015–2016, 6,429 km medium-voltage power lines with 76,430 pylons were checked for bird mortality in the Czech Republic. 1,326 bird victims of power lines were found, 156 of which died after collisions, and 1,170 birds were electrocuted. They belonged to 60 species from 12 orders, and birds of prey made up almost half of all victims. Steel pylons bearing several cross-arms including upper and crosswise jumpers were identified as most dangerous from the electrocution point of view. On the other hand, pylons in straight lines with Pařát cross-arms (triangular arrangement of conductors without any horizontal bar) were among the least dangerous, and when they had a simple perch fitted below the cross-arm, no mortality was recorded. But these pylons are new in practice and despite becoming widely used recently, they form less than one tenth of all pylons in the Czech Republic. On other pylons various types of mitigation measures have been installed. Commonly used plastic covers and plastic strips have proved to be especially effective, but only in cases when they are undamaged and correctly installed.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73896043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gális, Ladislav Naďo, E. Hapl, J. Šmídt, L. Deutschová, J. Chavko
Abstract Collisions and electrocutions on power lines are known to kill large numbers of birds annually on a global scale. We conducted comprehensive research focused on bird mortality caused by 22 kV and 110 kV distribution power lines in 13 Special Protection Areas in Slovakia. In the period between December 2014 and February 2016, 6,235 km of power lines were inspected twice during two periods (12/2014–03/2015 and 04/2015–02/2016) of field survey. In addition an intensive study was conducted during the second field survey at one-month intervals on power lines identified as the most dangerous for birds to collide with. As a result, 4,353 bird carcasses and bird remains representing 84 bird species and 14 orders were identified. Electrocution was suspected for 76.72% and collision for 23.28% of fatalities. Raptors were associated with 40% of all identified victims of electrocution. Two peaks of incidence were recorded, the first in March with a high rate of electrocutions as well as collisions of swans, pheasants, common blackbirds, ducks and herons, and the second in September predominantly featuring electrocution of raptors, magpies and corvids. We were unable to quantify seasonal patterns of mortality due to the limited sample of repeated mortality surveys resulting from the large grid of inspected power lines. We conducted comprehensive statistical analysis of more than 100 configurations of pylons and calculated their potential risk towards birds. Strong spatial correlation was revealed in the data set. Metal branch pylons and corner pylons with exposed jumper wires passing over the supporting insulators above the cross arms were the most dangerous configuration, accounting for 34.72% of total recorded electrocution fatalities (0.13 carcass/pylon). Cases of electrocution were also recorded for two bird species of major conservation concern in Slovakia: saker falcon (Falco cherrug) and eastern imperial eagle (Aquila heliaca). The results of this study may substantially improve conservation management and policies needed to reduce bird mortality.
{"title":"Comprehensive analysis of bird mortality along power distribution lines in Slovakia","authors":"M. Gális, Ladislav Naďo, E. Hapl, J. Šmídt, L. Deutschová, J. Chavko","doi":"10.2478/srj-2019-0006","DOIUrl":"https://doi.org/10.2478/srj-2019-0006","url":null,"abstract":"Abstract Collisions and electrocutions on power lines are known to kill large numbers of birds annually on a global scale. We conducted comprehensive research focused on bird mortality caused by 22 kV and 110 kV distribution power lines in 13 Special Protection Areas in Slovakia. In the period between December 2014 and February 2016, 6,235 km of power lines were inspected twice during two periods (12/2014–03/2015 and 04/2015–02/2016) of field survey. In addition an intensive study was conducted during the second field survey at one-month intervals on power lines identified as the most dangerous for birds to collide with. As a result, 4,353 bird carcasses and bird remains representing 84 bird species and 14 orders were identified. Electrocution was suspected for 76.72% and collision for 23.28% of fatalities. Raptors were associated with 40% of all identified victims of electrocution. Two peaks of incidence were recorded, the first in March with a high rate of electrocutions as well as collisions of swans, pheasants, common blackbirds, ducks and herons, and the second in September predominantly featuring electrocution of raptors, magpies and corvids. We were unable to quantify seasonal patterns of mortality due to the limited sample of repeated mortality surveys resulting from the large grid of inspected power lines. We conducted comprehensive statistical analysis of more than 100 configurations of pylons and calculated their potential risk towards birds. Strong spatial correlation was revealed in the data set. Metal branch pylons and corner pylons with exposed jumper wires passing over the supporting insulators above the cross arms were the most dangerous configuration, accounting for 34.72% of total recorded electrocution fatalities (0.13 carcass/pylon). Cases of electrocution were also recorded for two bird species of major conservation concern in Slovakia: saker falcon (Falco cherrug) and eastern imperial eagle (Aquila heliaca). The results of this study may substantially improve conservation management and policies needed to reduce bird mortality.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80115694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Long-eared owls’ winter roosts located within forest, compared to their winter roosts in human settlements, often escape human attention. Only minimum information has been published about winter roosts located deep in the forest. During the years 2005 to 2016, we collected long-eared owl pellets at irregularly occupied forest winter roosts. Compared to the diet at winter roosts in human settlements, the long-eared owls roosting in the forest surprisingly significantly more frequently hunted the common vole. Moreover, we did not record higher consumption of forest mammal species in the diet of owls at forest winter roosts. Long-eared owls roosting in human settlements hunted significantly more birds. The results show that, despite the location of deep forest winter roosts, long-eared owls preferred hunting the common vole, i.e. hunting in open agricultural land. The study also points out the lack of knowledge about winter roosts located deep in the forest.
{"title":"Long-eared owls roosted in the forest, still hunted in open land","authors":"Filip Tulis, Michael C. Sevcik, J. Obuch","doi":"10.2478/srj-2019-0003","DOIUrl":"https://doi.org/10.2478/srj-2019-0003","url":null,"abstract":"Abstract Long-eared owls’ winter roosts located within forest, compared to their winter roosts in human settlements, often escape human attention. Only minimum information has been published about winter roosts located deep in the forest. During the years 2005 to 2016, we collected long-eared owl pellets at irregularly occupied forest winter roosts. Compared to the diet at winter roosts in human settlements, the long-eared owls roosting in the forest surprisingly significantly more frequently hunted the common vole. Moreover, we did not record higher consumption of forest mammal species in the diet of owls at forest winter roosts. Long-eared owls roosting in human settlements hunted significantly more birds. The results show that, despite the location of deep forest winter roosts, long-eared owls preferred hunting the common vole, i.e. hunting in open agricultural land. The study also points out the lack of knowledge about winter roosts located deep in the forest.","PeriodicalId":56343,"journal":{"name":"Slovak Raptor Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79258051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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