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Factors affecting predators' search for cryptic prey
Kuncová, Aneta ; Exnerová, Alice (advisor) ; Hotová Svádová, Kateřina (referee)
This thesis is focused on selected mechanisms, which affect predators' search for cryptic prey. The purpose was to compare information concerning existence, content, duration and circumstances related to formation of a visual search image and it's existence in relation to other sensual modalities. The search image research was carried on many animal species, both invertebrates and vertebrates, with most experiments being carried on birds, specifically blue jays (Cyanocitta cristata) and pidgeons (Columba livia). There are many alternative explanations for the results of those experiments, either negating the search image's existence or just adding to it. The majority of studies agrees upon the existence of search image, but the circumstances of it's formation, as well as its duration and content are specific both for different kinds of predators (depending on their foraging strategies) and different kinds of prey. The differences can also be found in the search image's duration, depending on 5 predator's foraging strategy and encounter frequency with target prey. A decrease in this frequency results in disappearance of search image for the given prey. The experiments also show that the information content concerning the searched target, an essential part of the search image, depends on the prey's...
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Effects of pattern, size and background contrast of prey on discrimination learning in avian predators
Kuncová, Aneta ; Exnerová, Alice (advisor) ; Komárek, Stanislav (referee)
The topic of this master thesis was the effects of pattern, size and background contrast of prey on discrimination learning of avian predators. The aim of this study was to investigate the influence of selected components of warning coloration on aversive discrimination learning of avian predators of different age and sex. The choosen model organism was the Great tit (Parus major). The comparision was done between hand-reared naïve birds and wild-caught adults of different age and sex. The experiment was taking place in the experimental cage with one way mirror. The experiment used a design of simultaneous task with two pray which differed in one component of the coloration (pattern, size and background kontrast). The differencies in the ability of discrimination learning was found just between hand-rared naïve birds and wild-caught adults. Better results were shown by the wild-caught adults. The ability of discrimination learning of wild-caught adults was not influenced by the age and sex. Pattern was the only significant component of the warning coloration due to which the birds were able to memorise the discrimination task. Key words: avoidance learning, unpalatable prey, pattern, size, background, contrast
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Effects of pattern, size and background contrast of prey on discrimination learning in avian predators
Kuncová, Aneta ; Exnerová, Alice (advisor) ; Komárek, Stanislav (referee)
The topic of this master thesis was the effects of pattern, size and background contrast of prey on discrimination learning of avian predators. The aim of this study was to investigate the influence of selected components of warning coloration on aversive discrimination learning of avian predators of different age and sex. The choosen model organism was the Great tit (Parus major). The comparision was done between hand-reared naïve birds and wild-caught adults of different age and sex. The experiment was taking place in the experimental cage with one way mirror. The experiment used a design of simultaneous task with two pray which differed in one component of the coloration (pattern, size and background kontrast). The differencies in the ability of discrimination learning was found just between hand-rared naïve birds and wild-caught adults. Better results were shown by the wild-caught adults. The ability of discrimination learning of wild-caught adults was not influenced by the age and sex. Pattern was the only significant component of the warning coloration due to which the birds were able to memorise the discrimination task. Key words: avoidance learning, unpalatable prey, pattern, size, background, contrast
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Factors affecting predators' search for cryptic prey
Kuncová, Aneta ; Exnerová, Alice (advisor) ; Hotová Svádová, Kateřina (referee)
This thesis is focused on selected mechanisms, which affect predators' search for cryptic prey. The purpose was to compare information concerning existence, content, duration and circumstances related to formation of a visual search image and it's existence in relation to other sensual modalities. The search image research was carried on many animal species, both invertebrates and vertebrates, with most experiments being carried on birds, specifically blue jays (Cyanocitta cristata) and pidgeons (Columba livia). There are many alternative explanations for the results of those experiments, either negating the search image's existence or just adding to it. The majority of studies agrees upon the existence of search image, but the circumstances of it's formation, as well as its duration and content are specific both for different kinds of predators (depending on their foraging strategies) and different kinds of prey. The differences can also be found in the search image's duration, depending on 5 predator's foraging strategy and encounter frequency with target prey. A decrease in this frequency results in disappearance of search image for the given prey. The experiments also show that the information content concerning the searched target, an essential part of the search image, depends on the prey's...
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