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Effect of social learning on avoidance of aposematic prey in avian predators
Bělová, Magdalena ; Exnerová, Alice (advisor) ; Sedláček, František (referee)
Social learning is a topic of many studies. We tested the effect of social learning on the acquisition of avoidance against aposematic prey. We have chosen wild-caught adult and naive hand-reared juvenile great tits (Parus major) as a model predator species, because their individual avoidance learnig of aposematic prey is well-studied. We used red and green paper dummies of bugs with a mealworm (Tenebrio molitor) stuck underneath as an artificial prey. Mealworms were soaked in water or in bitter-tasting solution of quinine. We used two types of conspecific demonstrators - naive birds that showed aversive reactions while tasting an unpalatable prey and experienced birds that were trained not to handle the unpalatable pray at all. We compared effects of both demonstrators on discrimination learning and we tested whether these effects differ in adult and juvenile birds. Observing an experienced demonstrator had an effect on the performance of observers at the beginning of learning process. The observers did not reject the unpalatable prey completely, but the number of trials in which they correctly chose the palatable prey was higher in comparison with birds that observed naive demonstrators and birds from the control group with no demonstrator. Latencies to handle the unpalatable prey in the first...
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Research on cognitive abilities in untrained birds
NÁCAROVÁ, Jana
This study investigates the cues used for predator recognition by wild-living untrained birds great tits (Parus major). The experimental approach is used to test the reaction to the variously modified dummies of sparrowhawk (Accipiter nisus) and pigeon (Columba livia f. domestica) under laboratory conditions. The role of key features (yellow eye, hooked beak and talons), colour and size is tested. The results imply that the presence of raptor-specific features is mostly necessary but not sufficient to recognize predator in the presented dummies. Following research revealed that the part of the variability in response of great tits can be taken on the account of personality.
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Effect of stimulus size in discrimination and categorization processes in birds
NÁCAROVÁ, Jana
The mechanism of predator categorization has not been understood well yet. I examined how coloration pattern and predator size influence categorization by a prey under laboratory conditions. I tested the reaction of great tit (Parus major) to the plush dummies of sparrowhawk (Accipiter nisus), coloured as sparrowhawk, pigeon, robin and great tit. The same color variations were made in the sizes of a sparrowhawk and great tit. My results indicate that the coloration plays the main role in the recognition. The size is not important in the dummies coloured as the predator and the conspecific but it plays a role in recognition of other tested dummies (coloured as the pigeon and robin).
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The great tit (\kur{Parus major}) as a model species in spatialy cognitive tasks
NÁCAR, David
In this thesis the spatial cognitive experiment with great tits (Parus major) as a model species is described. In this experiment tits learnt to respond to one of four response keys according the presented stimuli. Two types of stimuli were used: one of them contained configural information about response keys, but the other didn´t. The experiment tested the difference of using these two types of spatial information in great tits in two experimental designs. In the first design stimuli were presented in computer screen, in the other they were presented in the floor of experimental chamber. The thesis then discusses the performance of tits in two types of stimuli and two versions of experimental design and compares these results with pigeons in similar experiment.
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Key features and prototypes in visual predator recognition - laboratory experiments with Great Tit (\kur{Parus major})
TUMOVÁ, Petra
Categorization of predators is fundamental for birds? life. However, the mechanism is not well explained yet. Two basic theories of categorization were tested in the laboratory conditions, where we have the possibility to focus on the behavior of each individuum. In the experiments we focused on the relevance of the key features and colour patterns. The responses of the Great Tit to variously modified dummies of Sparrowhawk were observed. The results confirm that the bird does not recognize the predator only on the basis of the key features and the colour patterns have a essential influence on the categorization. Categorization of the predator is a complex process and it cannot be explained only on the basis of one psychological theory. A combination of the key features and a prototype of a particular category learned throughout its life is probably used.
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Pigeon with sparrowhawk head: friend or enemy?
NÁCAROVÁ, Jana
The mechanism of predator recognition hasn´t been understood well yet. There are two main theoretic attitudes to this problem. Feature theory claims that animals use only some key features of the stimuli for categorization. The other opinion is that animals have a general concept how the predator should look like and local features aren't so important. We examined these theories under labor conditions. We tested the reaction of great tit (Parus major) on wooded dummies of the sparrowhawk (Accipiter nisus), pigeon (Columba livia f. domesticus) and chimeras between them that differed in the type of head. Our results show, that great tits probably use combination of both approaches to recognize the predator.
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