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Antipredatory behaviour of Red-backed Shrike: the role of sign stimuli in a predator recognition
Součková, Tereza ; Fuchs, Roman (advisor) ; Hořák, David (referee)
This thesis summarizes findings on a recognition and categorization of different sorts of stimuli at birds, it deals with predator recognition in the Red-backed Shrike (Lanius collurio) in its practical part. The aim of my study was to examine if Red-backed Shrikes follow by sign stimuli or colour of stimulus during the predator recognition. I performed my research by means of experiments with dummies, I have observed antipredatory reactions of Red-backed Shrikes on various types of dummies which differ in the presence or absence of features of raptor or in the different coloration. I concluded according to Shrikes' reactions that during the predator recognition the information on sign stimuli playes the principal role, but only this information alone is not fully sufficient. Antipredatory behaviour of the Red-backed Shrike was also influenced by sex of bird apart from type of dummy, males were more active during the nest defence than females.
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Are body size and specific species colouration important cues for predator recognition by their potencial prey? Diplomová práce
Antonová, Kateřina ; Fuchs, Roman (advisor) ; Sedláček, Ondřej (referee)
I tested influence of a body size and overal colouration in feeders experiments on recognition of sparrowhawk (Accipiter nisus) by chosen species of passerine. Experiments were conducted in years 2015 ̶ 2018. I used a plush dummies which carried a specific featuress of raptor (hooked beak, claws) and specific features of genus Accipiter (yellow eyes, respectively yellow eyes and overal colouration). As a control, dummy of harmless pigeon was used. Smaller dummies (size of a great tit) were not recognized as a raptor regardless of colouration. Large dummies with colouration of great tit and pigeon were not recognized as a raptor as well. On a contrary, large dummy with colouration of robin was recognized as a raptor, respectively sparrowhawk. Most birds who were flying to the feeders, at first payed attention to global features (size, overal colouration). If these features belong to well-known harmless bird, then local features (particular) which characterize raptor or sparrowhawk had no effect. Birds did not pay attention to them. Therefore it depends on a context, in which potential local key features occure.
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Antipredatory behaviour of Red-backed Shrike: the role of sign stimuli in a predator recognition
Součková, Tereza ; Fuchs, Roman (advisor) ; Hořák, David (referee)
This thesis summarizes findings on a recognition and categorization of different sorts of stimuli at birds, it deals with predator recognition in the Red-backed Shrike (Lanius collurio) in its practical part. The aim of my study was to examine if Red-backed Shrikes follow by sign stimuli or colour of stimulus during the predator recognition. I performed my research by means of experiments with dummies, I have observed antipredatory reactions of Red-backed Shrikes on various types of dummies which differ in the presence or absence of features of raptor or in the different coloration. I concluded according to Shrikes' reactions that during the predator recognition the information on sign stimuli playes the principal role, but only this information alone is not fully sufficient. Antipredatory behaviour of the Red-backed Shrike was also influenced by sex of bird apart from type of dummy, males were more active during the nest defence than females.
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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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