Fighting and flirting are the main evolutionary forces behind the development of bird song and bo... more Fighting and flirting are the main evolutionary forces behind the development of bird song and both contribute to different song characteristics. By comparison of vocalisations throughout bird taxa, we can help to reconstruct the evolutionary history of the song. In this study, we provide the first detailed analysis of song structure and song type variability in the Black-headed Bunting (Emberiza melanocephala). We quantify the fine structural characteristics of the song and describe the song and syllable repertoire size. Further, we describe intraindividual song variability over time and interindividual song variability over space, and we explore whether this species uses syntactic rules to create songs. Our analyses reveal that the Black-headed Bunting has a short yet rather complex song and that the syllable pool is extensive. Its song is constructed of three parts that differ in both complexity and rhythm, suggesting the use of syntactic rules in constructing a song. The male song is typically built of 9–13 syllables, with 7–12 that are non-repetitive. Each male sings only one stereotyped song, which remains identical throughout the male’s lifespan, providing evidence for age-limited song learning. Songs are individually distinct, suggesting the importance of song in individual recognition of males. Two spatial levels of song variation in the Black-headed Bunting are shown. On a microgeographical level, relatively small song neighbourhoods are formed with a handful of birds singing the same song type. On a macrogeographical level, dialects can be distinguished by the end part of a song. The most striking feature of the male Black-headed Bunting song is the immense variability of song types. Typically, only a small number of males shared the same song type, and males with unique song types occurred frequently as well. The high song complexity and single-song repertoire found in the Black-headed Bunting could reflect a high level of polygyny and a low level of parental care, therefore pointing to strong intersexual selection on the male song.
Proceeding of the 7th Conference of the European Ornithologists' Union
Although urbanization generally decreases biodiversity of an area, some urban areas may provide b... more Although urbanization generally decreases biodiversity of an area, some urban areas may provide beneficial conditions for existence of some species. Urban forests may provide better habitat conditions for woodpeckers than surrounding non-urban but managed forests if specific habitat and area requirements are satisfied. Very dense populations of middle spotted Dendrocopos medius (29 p/km2) and great spotted woodpecker Dendrocopos major (43 p/km2) exist in the Maksimir park of Zagreb (Croatia). Total area of park is 3 km2 with 1.5 km2 of compact old sessile oak-hornbeam forest which is in some parts older than 300 years. In order to test hypothesis that in such dense populations home ranges should be small, we radio-tracked 11 adult great spotted and 7 adult middle spotted woodpeckers to investigate their spacing behavior. The field work was carried out in breeding seasons of 2007 and 2008, from the second half of May to the end of June. Home-range sizes (95% MCP) in great spotted woo...
Museum skins of the Black-eared Wheatear Oenante hispanica from the eastern Adriatic coast were e... more Museum skins of the Black-eared Wheatear Oenante hispanica from the eastern Adriatic coast were examined in order to identify subspe-cies. All 91 examined skins belong to O. h. melanoleuca. Wing lengths (88-96 mm in adult males, 87-93.5 mm in 2 nd year males and 84-92 mm in females) are among the longest for this species. The proportion of the black-throated morph was 56.5% in males and 40.9% in females. Biomet-ric measures and variability in tail pattern are described.
In the fourth report of the Croatian Birds Rarities Committee, new accepted records of rare birds... more In the fourth report of the Croatian Birds Rarities Committee, new accepted records of rare birds that were submitted to the committee in the period 2012-2016 are reported. Ten species, of which one is treated as escape from captivity, and two subspecies have been observed in Croatia for the first time. The list of birds of Croatia now holds 396 species in categories A, B and C, and 5 species in category C E. Further 11 species are recorded in category E and one in category D, and these are not included in the list of birds of Croatia. Three species have been removed from the rare birds list due to the increasing number of their observations. The list of rare bird taxa now includes 72 species, of which 5 are included in category C E, and 4 subspecies. Additional eleven species are treated as escapees (category E) and one as probable escapee (category D).
From the north-eastern German breeding areas of the Great Cormorant (Mecklenburg-Western Pomerani... more From the north-eastern German breeding areas of the Great Cormorant (Mecklenburg-Western Pomerania, Brandenburg, Saxony, Saxony-Anhalt), ringing data are available for a period of more than 80 years. These data are unique for the Baltic Sea area. Cormorants were being ringed as early as during the 1930s, and ringing was re-started after World War II in 1957. These ringing efforts resulted in a total of 2.061 recoveries until October 31, 2014 (including both ring recoveries and re-sightings). This number includes 287 recoveries from the winter season (16 November – 15 February), being used for the present analyses. During the 1930s, three different migration routes could be distinguished: The south-eastern route, following the eastern coast of the Adriatic Sea down to Greece, in some cases even Turkey; the southern route, crossing Italy or Corsica/Sardinia to North Africa, and the western route to Western Europe. The proportion of birds using the south-eastern route started to decline during the 1980s. Currently, this migration route is abandoned. This development is related to the population increase and range expansion of the European breeding population since the beginning of the 1980s. Data from the Croatian Bird Ringing Centre shows, that winter recoveries in recent times mainly refer to birds from the northern and eastern Baltic, whereas recoveries from the south-western Baltic (Denmark, Schleswig-Holstein and Mecklenburg-Western Pomerania) are missing. For the southern migration route, a decline of the migration distance is obvious. The mean co-ordinate of recoveries currently lies 740 km north of the mean co-ordinate found during the 1930s. Recoveries from North Africa have become rather exceptional in recent times. Recoveries from the western migration route spread over the whole continent from the Mediterranean to the Atlantic coast. The birds may reach southern Spain, Portugal and even Morocco. There was no significant change in migration distance from 1932/33 until 2009/10; however, recently (2010/11 - 2013/14) the distance has increased significantly. Simultaneously, the proportion of birds using this migration route increased. Wintering in areas near to the region of origin has increased since the 1980s. Recoveries within a distance of <500 km from the reference point (i.e. the mean co-ordinate of the ringing sites) were rare until the 1980s, but after 1999/00 about one third of the Cormorants was recorded within this radius. Short distance migrants, however, usually do not remain in their regions of origin, but show a pronounced south-west migration. The trend of wintering in areas near to the region of origin corresponds temporally to the establishment of winter populations on the Baltic coast. Birds wintering on the Baltic Sea coast of Mecklenburg-Western Pomerania mainly originate from more northern or eastern Baltic areas (Denmark, Sweden, Finland, Estonia, Russia), and the proportion of East German birds recovered here during the winter season is low. Finally, another noticeable change is the use of inland sites for wintering. During the 1930s, the vast majority (94 %) of wintering Cormorants was found in coastal areas. Since the 1980s, the proportion of birds recorded at inland sites exceeds 50 %.
Average global temperatures in Earth have increased over the past 100 years and climate change im... more Average global temperatures in Earth have increased over the past 100 years and climate change impacts wildlife in countless ways. Numerous of the works demonstrated climatic impacts on bird phenology. We used 26 years of data from black redstart (Phoenicurus ochruros) in population from Mokrice village (northwestern Croatia), 1987-2012. Correlation between timing of arrivals and year was significant. Black redstart arrival dates have become 8.84 days earlier during the research period. The relationship between local mean spring temperatures and year was significant. The date trends in spring migration correspond with increasing mean spring air temperatures (March-April). This result suggests that black redstart respond to air spring temperatures by earlier arrival at breeding grounds. Our results are consistent with many other long-term studies of the timing of birds migration and suggest that air spring temperature change may be responsible for shifts in arrival dates.
Temperature and precipitation are known to have an effect on the onset of bird migration, but stu... more Temperature and precipitation are known to have an effect on the onset of bird migration, but studies were mostly taken on Passeriformes. Between 2001 and 2006 we studied the wintering numbers and dynamics of migration of a short-distance migrant, blackheaded gull, Chroicocephalus ridibundus, on Zagreb city rubbish dump, Jakuševec. Mean monthly numbers showed significant negative correlation with the local winter temperature, with higher numbers in the coldest months. Arrival of black-headed gulls correlated with North Atlantic Oscillation (NAO) index for the period from September to November. Precipitation didn’t have an effect on the timing of migration or maximum numbers. Our results indicate that arrival time for black-headed gull depended on the conditions in breeding areas, while departure time did not respond to NAO or local temperature.
The distribution and abundance of woodpecker species in the mountain forests of Croatian Karst re... more The distribution and abundance of woodpecker species in the mountain forests of Croatian Karst region were studied from 2004 to 2007. The aim was to establish the basis for monitoring populations of woodpeckers as part of an extensive Karst Ecosystems Conservation Project. Since woodpeckers are regarded as a key forest species, they were used as indicators of forest biodiversity and naturalness. The study was conducted in the highest part of the Croatian Dinaric Alps. Four mountain forest habitats types were covered: beech forests, fir-beech forests, beech-pine forest and spruce forests. Woodpeckers were counted on nine transects. Each transect contained 15 standpoints for census. Sound luring was used. Six species of woodpeckers were found in the research area: Lesser Spotted, Great Spotted, White-backed, Three-toed, Grey-headed and Black Woodpecker. The former four species were selected for future monitoring. Results of the census – that is, the distribution and the abundance of w...
Fighting and flirting are the main evolutionary forces behind the development of bird song and bo... more Fighting and flirting are the main evolutionary forces behind the development of bird song and both contribute to different song characteristics. By comparison of vocalisations throughout bird taxa, we can help to reconstruct the evolutionary history of the song. In this study, we provide the first detailed analysis of song structure and song type variability in the Black-headed Bunting (Emberiza melanocephala). We quantify the fine structural characteristics of the song and describe the song and syllable repertoire size. Further, we describe intraindividual song variability over time and interindividual song variability over space, and we explore whether this species uses syntactic rules to create songs. Our analyses reveal that the Black-headed Bunting has a short yet rather complex song and that the syllable pool is extensive. Its song is constructed of three parts that differ in both complexity and rhythm, suggesting the use of syntactic rules in constructing a song. The male song is typically built of 9–13 syllables, with 7–12 that are non-repetitive. Each male sings only one stereotyped song, which remains identical throughout the male’s lifespan, providing evidence for age-limited song learning. Songs are individually distinct, suggesting the importance of song in individual recognition of males. Two spatial levels of song variation in the Black-headed Bunting are shown. On a microgeographical level, relatively small song neighbourhoods are formed with a handful of birds singing the same song type. On a macrogeographical level, dialects can be distinguished by the end part of a song. The most striking feature of the male Black-headed Bunting song is the immense variability of song types. Typically, only a small number of males shared the same song type, and males with unique song types occurred frequently as well. The high song complexity and single-song repertoire found in the Black-headed Bunting could reflect a high level of polygyny and a low level of parental care, therefore pointing to strong intersexual selection on the male song.
Proceeding of the 7th Conference of the European Ornithologists' Union
Although urbanization generally decreases biodiversity of an area, some urban areas may provide b... more Although urbanization generally decreases biodiversity of an area, some urban areas may provide beneficial conditions for existence of some species. Urban forests may provide better habitat conditions for woodpeckers than surrounding non-urban but managed forests if specific habitat and area requirements are satisfied. Very dense populations of middle spotted Dendrocopos medius (29 p/km2) and great spotted woodpecker Dendrocopos major (43 p/km2) exist in the Maksimir park of Zagreb (Croatia). Total area of park is 3 km2 with 1.5 km2 of compact old sessile oak-hornbeam forest which is in some parts older than 300 years. In order to test hypothesis that in such dense populations home ranges should be small, we radio-tracked 11 adult great spotted and 7 adult middle spotted woodpeckers to investigate their spacing behavior. The field work was carried out in breeding seasons of 2007 and 2008, from the second half of May to the end of June. Home-range sizes (95% MCP) in great spotted woo...
Museum skins of the Black-eared Wheatear Oenante hispanica from the eastern Adriatic coast were e... more Museum skins of the Black-eared Wheatear Oenante hispanica from the eastern Adriatic coast were examined in order to identify subspe-cies. All 91 examined skins belong to O. h. melanoleuca. Wing lengths (88-96 mm in adult males, 87-93.5 mm in 2 nd year males and 84-92 mm in females) are among the longest for this species. The proportion of the black-throated morph was 56.5% in males and 40.9% in females. Biomet-ric measures and variability in tail pattern are described.
In the fourth report of the Croatian Birds Rarities Committee, new accepted records of rare birds... more In the fourth report of the Croatian Birds Rarities Committee, new accepted records of rare birds that were submitted to the committee in the period 2012-2016 are reported. Ten species, of which one is treated as escape from captivity, and two subspecies have been observed in Croatia for the first time. The list of birds of Croatia now holds 396 species in categories A, B and C, and 5 species in category C E. Further 11 species are recorded in category E and one in category D, and these are not included in the list of birds of Croatia. Three species have been removed from the rare birds list due to the increasing number of their observations. The list of rare bird taxa now includes 72 species, of which 5 are included in category C E, and 4 subspecies. Additional eleven species are treated as escapees (category E) and one as probable escapee (category D).
From the north-eastern German breeding areas of the Great Cormorant (Mecklenburg-Western Pomerani... more From the north-eastern German breeding areas of the Great Cormorant (Mecklenburg-Western Pomerania, Brandenburg, Saxony, Saxony-Anhalt), ringing data are available for a period of more than 80 years. These data are unique for the Baltic Sea area. Cormorants were being ringed as early as during the 1930s, and ringing was re-started after World War II in 1957. These ringing efforts resulted in a total of 2.061 recoveries until October 31, 2014 (including both ring recoveries and re-sightings). This number includes 287 recoveries from the winter season (16 November – 15 February), being used for the present analyses. During the 1930s, three different migration routes could be distinguished: The south-eastern route, following the eastern coast of the Adriatic Sea down to Greece, in some cases even Turkey; the southern route, crossing Italy or Corsica/Sardinia to North Africa, and the western route to Western Europe. The proportion of birds using the south-eastern route started to decline during the 1980s. Currently, this migration route is abandoned. This development is related to the population increase and range expansion of the European breeding population since the beginning of the 1980s. Data from the Croatian Bird Ringing Centre shows, that winter recoveries in recent times mainly refer to birds from the northern and eastern Baltic, whereas recoveries from the south-western Baltic (Denmark, Schleswig-Holstein and Mecklenburg-Western Pomerania) are missing. For the southern migration route, a decline of the migration distance is obvious. The mean co-ordinate of recoveries currently lies 740 km north of the mean co-ordinate found during the 1930s. Recoveries from North Africa have become rather exceptional in recent times. Recoveries from the western migration route spread over the whole continent from the Mediterranean to the Atlantic coast. The birds may reach southern Spain, Portugal and even Morocco. There was no significant change in migration distance from 1932/33 until 2009/10; however, recently (2010/11 - 2013/14) the distance has increased significantly. Simultaneously, the proportion of birds using this migration route increased. Wintering in areas near to the region of origin has increased since the 1980s. Recoveries within a distance of <500 km from the reference point (i.e. the mean co-ordinate of the ringing sites) were rare until the 1980s, but after 1999/00 about one third of the Cormorants was recorded within this radius. Short distance migrants, however, usually do not remain in their regions of origin, but show a pronounced south-west migration. The trend of wintering in areas near to the region of origin corresponds temporally to the establishment of winter populations on the Baltic coast. Birds wintering on the Baltic Sea coast of Mecklenburg-Western Pomerania mainly originate from more northern or eastern Baltic areas (Denmark, Sweden, Finland, Estonia, Russia), and the proportion of East German birds recovered here during the winter season is low. Finally, another noticeable change is the use of inland sites for wintering. During the 1930s, the vast majority (94 %) of wintering Cormorants was found in coastal areas. Since the 1980s, the proportion of birds recorded at inland sites exceeds 50 %.
Average global temperatures in Earth have increased over the past 100 years and climate change im... more Average global temperatures in Earth have increased over the past 100 years and climate change impacts wildlife in countless ways. Numerous of the works demonstrated climatic impacts on bird phenology. We used 26 years of data from black redstart (Phoenicurus ochruros) in population from Mokrice village (northwestern Croatia), 1987-2012. Correlation between timing of arrivals and year was significant. Black redstart arrival dates have become 8.84 days earlier during the research period. The relationship between local mean spring temperatures and year was significant. The date trends in spring migration correspond with increasing mean spring air temperatures (March-April). This result suggests that black redstart respond to air spring temperatures by earlier arrival at breeding grounds. Our results are consistent with many other long-term studies of the timing of birds migration and suggest that air spring temperature change may be responsible for shifts in arrival dates.
Temperature and precipitation are known to have an effect on the onset of bird migration, but stu... more Temperature and precipitation are known to have an effect on the onset of bird migration, but studies were mostly taken on Passeriformes. Between 2001 and 2006 we studied the wintering numbers and dynamics of migration of a short-distance migrant, blackheaded gull, Chroicocephalus ridibundus, on Zagreb city rubbish dump, Jakuševec. Mean monthly numbers showed significant negative correlation with the local winter temperature, with higher numbers in the coldest months. Arrival of black-headed gulls correlated with North Atlantic Oscillation (NAO) index for the period from September to November. Precipitation didn’t have an effect on the timing of migration or maximum numbers. Our results indicate that arrival time for black-headed gull depended on the conditions in breeding areas, while departure time did not respond to NAO or local temperature.
The distribution and abundance of woodpecker species in the mountain forests of Croatian Karst re... more The distribution and abundance of woodpecker species in the mountain forests of Croatian Karst region were studied from 2004 to 2007. The aim was to establish the basis for monitoring populations of woodpeckers as part of an extensive Karst Ecosystems Conservation Project. Since woodpeckers are regarded as a key forest species, they were used as indicators of forest biodiversity and naturalness. The study was conducted in the highest part of the Croatian Dinaric Alps. Four mountain forest habitats types were covered: beech forests, fir-beech forests, beech-pine forest and spruce forests. Woodpeckers were counted on nine transects. Each transect contained 15 standpoints for census. Sound luring was used. Six species of woodpeckers were found in the research area: Lesser Spotted, Great Spotted, White-backed, Three-toed, Grey-headed and Black Woodpecker. The former four species were selected for future monitoring. Results of the census – that is, the distribution and the abundance of w...
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During the 1930s, three different migration routes could be distinguished: The south-eastern route, following the eastern coast of the Adriatic Sea down to Greece, in some cases even Turkey; the southern route, crossing Italy or Corsica/Sardinia to North Africa, and the western route to Western Europe.
The proportion of birds using the south-eastern route started to decline during the 1980s. Currently, this migration route is abandoned. This development is related to the population increase and range expansion of the European breeding population since the beginning of the 1980s. Data from the Croatian Bird Ringing Centre shows, that winter recoveries in recent times mainly refer to birds from the northern and eastern Baltic, whereas recoveries from the south-western Baltic (Denmark, Schleswig-Holstein and Mecklenburg-Western Pomerania) are missing.
For the southern migration route, a decline of the migration distance is obvious. The mean co-ordinate of recoveries currently lies 740 km north of the mean co-ordinate found during the 1930s. Recoveries from North Africa have become rather exceptional in recent times.
Recoveries from the western migration route spread over the whole continent from the Mediterranean to the Atlantic coast. The birds may reach southern Spain, Portugal and even Morocco. There was no significant change in migration distance from 1932/33 until 2009/10; however, recently (2010/11 - 2013/14) the distance has increased significantly. Simultaneously, the proportion of birds using this migration route increased.
Wintering in areas near to the region of origin has increased since the 1980s. Recoveries within a distance of <500 km from the reference point (i.e. the mean co-ordinate of the ringing sites) were rare until the 1980s, but after 1999/00 about one third of the Cormorants was recorded within this radius. Short distance migrants, however, usually do not remain in their regions of origin, but show a pronounced south-west migration.
The trend of wintering in areas near to the region of origin corresponds temporally to the establishment of winter populations on the Baltic coast. Birds wintering on the Baltic Sea coast of Mecklenburg-Western Pomerania mainly originate from more northern or eastern Baltic areas (Denmark, Sweden, Finland, Estonia, Russia), and the proportion of East German birds recovered here during the winter season is low.
Finally, another noticeable change is the use of inland sites for wintering. During the 1930s, the vast majority (94 %) of wintering Cormorants was found in coastal areas. Since the 1980s, the proportion of birds recorded at inland sites exceeds 50 %.
During the 1930s, three different migration routes could be distinguished: The south-eastern route, following the eastern coast of the Adriatic Sea down to Greece, in some cases even Turkey; the southern route, crossing Italy or Corsica/Sardinia to North Africa, and the western route to Western Europe.
The proportion of birds using the south-eastern route started to decline during the 1980s. Currently, this migration route is abandoned. This development is related to the population increase and range expansion of the European breeding population since the beginning of the 1980s. Data from the Croatian Bird Ringing Centre shows, that winter recoveries in recent times mainly refer to birds from the northern and eastern Baltic, whereas recoveries from the south-western Baltic (Denmark, Schleswig-Holstein and Mecklenburg-Western Pomerania) are missing.
For the southern migration route, a decline of the migration distance is obvious. The mean co-ordinate of recoveries currently lies 740 km north of the mean co-ordinate found during the 1930s. Recoveries from North Africa have become rather exceptional in recent times.
Recoveries from the western migration route spread over the whole continent from the Mediterranean to the Atlantic coast. The birds may reach southern Spain, Portugal and even Morocco. There was no significant change in migration distance from 1932/33 until 2009/10; however, recently (2010/11 - 2013/14) the distance has increased significantly. Simultaneously, the proportion of birds using this migration route increased.
Wintering in areas near to the region of origin has increased since the 1980s. Recoveries within a distance of <500 km from the reference point (i.e. the mean co-ordinate of the ringing sites) were rare until the 1980s, but after 1999/00 about one third of the Cormorants was recorded within this radius. Short distance migrants, however, usually do not remain in their regions of origin, but show a pronounced south-west migration.
The trend of wintering in areas near to the region of origin corresponds temporally to the establishment of winter populations on the Baltic coast. Birds wintering on the Baltic Sea coast of Mecklenburg-Western Pomerania mainly originate from more northern or eastern Baltic areas (Denmark, Sweden, Finland, Estonia, Russia), and the proportion of East German birds recovered here during the winter season is low.
Finally, another noticeable change is the use of inland sites for wintering. During the 1930s, the vast majority (94 %) of wintering Cormorants was found in coastal areas. Since the 1980s, the proportion of birds recorded at inland sites exceeds 50 %.