Issues

Journal & Issues

Volume 15 (2021): Issue 1 (December 2021)

Volume 14 (2020): Issue 1 (December 2020)

Volume 13 (2019): Issue 1 (December 2019)

Volume 12 (2018): Issue 1 (December 2018)

Volume 11 (2017): Issue 1 (December 2017)

Volume 10 (2016): Issue 1 (December 2016)

Volume 9 (2015): Issue 1 (January 2015)
Special Issue Title: International Conference on the Conservation of the Lesser Spotted Eagle, Košická Belá, Slovakia, 2014

Volume 8 (2014): Issue 2014 (January 2014)
Proceedings from VII. International Conference on the Conservation of the Eastern Imperial Eagle, Bratislava, Slovakia, 2013

Volume 8 (2014): Issue 2 (December 2014)

Volume 7 (2013): Issue 2013 (January 2013)

Volume 6 (2012): Issue 2012 (January 2012)

Volume 5 (2011): Issue 2011 (January 2011)

Volume 4 (2010): Issue 2010 (January 2010)

Volume 3 (2009): Issue 2009 (January 2009)

Volume 2 (2008): Issue 2008 (January 2008)

Volume 1 (2007): Issue 2007 (January 2007)

Journal Details
Format
Journal
eISSN
2644-5247
First Published
09 Nov 2012
Publication timeframe
1 time per year
Languages
English

Search

Volume 14 (2020): Issue 1 (December 2020)

Journal Details
Format
Journal
eISSN
2644-5247
First Published
09 Nov 2012
Publication timeframe
1 time per year
Languages
English

Search

7 Articles
Open Access

Spatial distribution of four sympatric owl species in Carpathian montane forests

Published Online: 30 Apr 2021
Page range: 1 - 13

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.

Keywords

  • spatial arrangement
  • territoriality
  • habitat characteristics
  • point pattern analysis
Open Access

Diet of the lesser kestrel Falco naumanni at post-breeding roosts in southern Albania

Published Online: 30 Apr 2021
Page range: 15 - 22

Abstract

Abstract

The lesser kestrel is an insectivorous and migratory falcon species, frequently using communal roosts in the post-breeding period in southern Europe. Using pellet analysis from two post-breeding roosting sites in southern Albania collected in August 2017, we identified 1539 prey items belonging to approximately 58 prey species, 20 families and 7 orders in 110 pellets from two sites. Invertebrates made up the major part of the diet spectrum (PNI = 99.8 %, PFI = 100 %). Invertebrate prey body size varied between 8 and 62 mm (mean 28.1 mm). Bush-crickets (Tettigoniidae) and locusts (Acrididae) were the most abundant and frequent prey groups (PNI = 33 % resp. 48.6 % and PFI = 97 % resp. 94 %). Within the bush-cricket family we could identify the species of genera Tettigonia, Decticus, Platycleis, Isophya and Metrioptera. The species of genera Calliptamus, Stenobothrus and Locusta belonged among the locust species identified in the food. Birds and mammals were found in pellets only occasionally. The prey composition was rather similar at both studied sites, while locusts (Acrididae) were more abundant at the Jorgucat site and bush-crickets (Tettigonioidea) at the Mollas site in the same time. Prey groups Scarabeidae beetles and other beetles (Coleoptera other) were more abundant and frequent at Mollas than at Jorgucat, and spiders were more frequent at Jorgucat. These results suggest that the high abundance of orthopterans and beetles in the food supply in certain localities is the main reason for selection and stable occupancy of these massive communal roosting sites by lesser kestrels in Albania.

Keywords

  • lesser kestrel
  • foraging
  • insectivores
  • communal roosting
  • agriculture
Open Access

Comparison of orbital asymmetries among some raptor species: “when size does not matter”

Published Online: 30 Apr 2021
Page range: 23 - 27

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.

Keywords

  • Accipitriformes
  • directional asymmetry
  • fluctuating asymmetry
  • orbital shape
  • Strigiformes
  • vision
Open Access

Changes in the Eurasian eagle-owl (Bubo bubo) population in Czechia and their association with legal protection

Published Online: 30 Apr 2021
Page range: 29 - 44

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.

Keywords

  • owls
  • lure hunting
  • nature conservation
  • Central Europe
Open Access

Summary of raptor and owl ringing in Slovakia in the period from 2012 to 2019

Published Online: 30 Apr 2021
Page range: 45 - 72

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.

Keywords

  • birds of prey
  • owls
  • ringing data
  • recoveries
  • Slovakia
Open Access

Age of maturity and exceptionally distant natal dispersal of over 500 km by a male lesser spotted eagle Clanga pomarina

Published Online: 30 Apr 2021
Page range: 73 - 76

Abstract

Abstract

According to previous studies using colour rings, lesser spotted eagles Clanga pomarina have established breeding territories up to 249 km from their natal site. A colour-ringed lesser spotted eagle nestling from NE Poland settled 540 km further west in NE Germany. This male was discovered at the age of six and nested there for several years. This finding is all the more remarkable because the bird was a male, which in large eagles typically settle nearer to their natal sites than females. They apparently reproduce successfully for the first time later than females, normally at the age of five.

Keywords

  • age of maturity
  • distant settling
  • ringing
  • lesser spotted eagle
Open Access

The identity of Azara’s description No. 18 “Gavilán mixto pintado” is a juvenile Harris’s hawk (Parabuteo unicinctus)

Published Online: 30 Apr 2021
Page range: 77 - 80

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.

Keywords

  • Gavilán mixto
  • Great Black Hawk
  • Paraguay
7 Articles
Open Access

Spatial distribution of four sympatric owl species in Carpathian montane forests

Published Online: 30 Apr 2021
Page range: 1 - 13

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.

Keywords

  • spatial arrangement
  • territoriality
  • habitat characteristics
  • point pattern analysis
Open Access

Diet of the lesser kestrel Falco naumanni at post-breeding roosts in southern Albania

Published Online: 30 Apr 2021
Page range: 15 - 22

Abstract

Abstract

The lesser kestrel is an insectivorous and migratory falcon species, frequently using communal roosts in the post-breeding period in southern Europe. Using pellet analysis from two post-breeding roosting sites in southern Albania collected in August 2017, we identified 1539 prey items belonging to approximately 58 prey species, 20 families and 7 orders in 110 pellets from two sites. Invertebrates made up the major part of the diet spectrum (PNI = 99.8 %, PFI = 100 %). Invertebrate prey body size varied between 8 and 62 mm (mean 28.1 mm). Bush-crickets (Tettigoniidae) and locusts (Acrididae) were the most abundant and frequent prey groups (PNI = 33 % resp. 48.6 % and PFI = 97 % resp. 94 %). Within the bush-cricket family we could identify the species of genera Tettigonia, Decticus, Platycleis, Isophya and Metrioptera. The species of genera Calliptamus, Stenobothrus and Locusta belonged among the locust species identified in the food. Birds and mammals were found in pellets only occasionally. The prey composition was rather similar at both studied sites, while locusts (Acrididae) were more abundant at the Jorgucat site and bush-crickets (Tettigonioidea) at the Mollas site in the same time. Prey groups Scarabeidae beetles and other beetles (Coleoptera other) were more abundant and frequent at Mollas than at Jorgucat, and spiders were more frequent at Jorgucat. These results suggest that the high abundance of orthopterans and beetles in the food supply in certain localities is the main reason for selection and stable occupancy of these massive communal roosting sites by lesser kestrels in Albania.

Keywords

  • lesser kestrel
  • foraging
  • insectivores
  • communal roosting
  • agriculture
Open Access

Comparison of orbital asymmetries among some raptor species: “when size does not matter”

Published Online: 30 Apr 2021
Page range: 23 - 27

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.

Keywords

  • Accipitriformes
  • directional asymmetry
  • fluctuating asymmetry
  • orbital shape
  • Strigiformes
  • vision
Open Access

Changes in the Eurasian eagle-owl (Bubo bubo) population in Czechia and their association with legal protection

Published Online: 30 Apr 2021
Page range: 29 - 44

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.

Keywords

  • owls
  • lure hunting
  • nature conservation
  • Central Europe
Open Access

Summary of raptor and owl ringing in Slovakia in the period from 2012 to 2019

Published Online: 30 Apr 2021
Page range: 45 - 72

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.

Keywords

  • birds of prey
  • owls
  • ringing data
  • recoveries
  • Slovakia
Open Access

Age of maturity and exceptionally distant natal dispersal of over 500 km by a male lesser spotted eagle Clanga pomarina

Published Online: 30 Apr 2021
Page range: 73 - 76

Abstract

Abstract

According to previous studies using colour rings, lesser spotted eagles Clanga pomarina have established breeding territories up to 249 km from their natal site. A colour-ringed lesser spotted eagle nestling from NE Poland settled 540 km further west in NE Germany. This male was discovered at the age of six and nested there for several years. This finding is all the more remarkable because the bird was a male, which in large eagles typically settle nearer to their natal sites than females. They apparently reproduce successfully for the first time later than females, normally at the age of five.

Keywords

  • age of maturity
  • distant settling
  • ringing
  • lesser spotted eagle
Open Access

The identity of Azara’s description No. 18 “Gavilán mixto pintado” is a juvenile Harris’s hawk (Parabuteo unicinctus)

Published Online: 30 Apr 2021
Page range: 77 - 80

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.

Keywords

  • Gavilán mixto
  • Great Black Hawk
  • Paraguay

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