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How do bird species richness and abundance differ between military training areas and surrounding landscape? A case study from the Hradiště military area
Bušek, Ondřej ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....
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How do bird species richness and abundance differ between military training areas and surrounding landscape? A case study from the Hradiště military area
Bušek, Ondřej
Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....
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How do bird species richness and abundance differ between military training areas and surrounding landscape? A case study from the Hradiště military area
Bušek, Ondřej
Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....
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Effect of body-margin shape on detectability of cryptic prey
Machalková, Kateřina ; Exnerová, Alice (advisor) ; Hotová Svádová, Kateřina (referee)
5 Abstract Subject of many studies dealing with interactions of predator and prey is behaviour and reactions of those predators who distinguish their prey by visual signals. The aim of the study was to compare the detectability of prey with a simple or structured body-margin shape of cryptically coloured true bugs Dysodius crenulatus and Dysodius lunatus (Aradidae) using a different type of background (tree bark of Acer, Gleditschia and Tilia). Background photos were presented in black and white and colour. The test was performed on naive birds and on the wild-caught adults of the Great Tits (Parus major) and the Blue Tits (Cyanistes caeruleus). The experiment was performed in the experimental cage with one-sided mirror glass. The influence of the body-margin shape of the prey was evident for certain groups, but the effect was depending on the age and specie of the birds and the type of the background. Different times of the search for prey were encountered as it was more difficult for birds to search for structured body-margin shape and the birds found faster preys with simple ones. When searching on the colour background the Great Tits were faster than on black and white background. Naive birds of the Great Tits were in search of prey faster than adults and vice versa with the Blue Tits. A separate task...
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How do bird species richness and abundance differ between military training areas and surrounding landscape? A case study from the Hradiště military area
Bušek, Ondřej ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Since the beginning of the 20th century human land use changed drastically in Central Europe. These changes included: homogenization of the landscape mosaic, intensification of agriculture, urbanization and land abandonment. In turn, these changes affected bird species and perhaps most significantly manifested in population decline of open habitat birds. Therefore, it is important to investigate sites, which were not affected by the changes mentioned above, such as military training areas (MTAs) - places dedicated to training of armed forces. Previous studies have shown that MTAs seem to host remarkably high bird diversity and abundant populations of bird species of conservation concern. This may be caused by two major factors. First, closure of MTAs to all human activies besides military training spared them of the landscape changes mentioned above. Second, the military training itself produces a very heterogeneous habitat mosaic that allows coexistence of many species with different ecological requirements. To my knowledge, no study compared bird assemblages between MTAs and surrounding landscape directly. At the same time, such data are crucial to assess the value of MTAs for bird conservation reliably and, as a consequence, they enable to think more deeply about mechanism generating this value....
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Factors affecting prey detectability for visual predators
Machalková, Kateřina ; Exnerová, Alice (advisor) ; Javůrková, Veronika (referee)
The cryptic coloration is one of the main ways to protect prey before the visually directing predators. Most animals use two basic strategies of crypsis, background-matching and disruptive coloration. The aim of this thesis was to summarize and evaluate knowledge about different strategies of cryptic coloration. The study was mainly focused on the confrontation between insect prey and predator bird. Experimental studies are comparing the effectiveness of cryptic coloration of prey by a combination of background-matching and disruptive coloration with prey characteristics (inner pattern contrast, background contrast, shape and pattern distribution, symmetry) or background parameters (background complexity, multiple backgrounds, the distance between the prey and the predator) that affect detectability. The results of the study conclude that disruptive coloration pattern in cryptic prey has better effects than the strategy of background-matching. Prey characteristics can affect detectability, but the results of individual studies are not conclusive. Even the background parameters results were unambiguous, the highest efficiency for prey detection time was a combination of disruptive coloration and the background complexity. The issue of camouflage is so complex that the majority of studies do not have...
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