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Rozpoznávání predátora netrénovanými ptáky: obrana hnízda
URBANOVÁ, Nela
Despite object categorization being an important ability for the survival of wild animals, the principles behind this ability have been only scarcely studied using wild-ranging, untrained animals. Reiterating our previous study undertaken with wild-ranging titmice on winter feeders (Nováková et al. Behav Process 143:7-12, 2017), we aimed to test two hypotheses of object recognition proposed by animal psychology studies: the particulate feature theory and recognition by components in the methodological paradigm of nest defence. We tested whether the parents of the red-backed shrike (Lanius collurio) recognize the dummies of the common kestrel (Falco tinnunculus), which is a potential predator of large chicks or fledglings, as a threat in case when their body parts are scrambled. The kestrel dummy was presented with the head at the top, in the middle, and at the bottom of the body. We showed that the shrikes did not consider dummies of a kestrel with an inappropriately placed head as a threat to the nest and attacked it equally scarcely as the harmless control. These results support the theory of recognition by components, presuming that the mutual position of body parts is essential for appropriate recognition of the object. When the body parts were scrambled, most of shrikes were not able to identify the kestrel in such an object despite all local features (eye, beak, colouration, and claws) being present. Nevertheless, shrikes did not consider the scrambled dummies as completely harmless, because they fed their chicks in their presence significantly less often than in the presence of harmless control.
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Rozpoznávají sýkory kukačku obecnou (\kur{Cuculus canorus}) od krahujce obecného (\kur{Accipiter nisus})?
ROTOVÁ, Alžběta
The thesis includes a review of the topic of brood parasitism, with focus on the most common European brood parasite, the common cuckoo (Cuculus canorus). Experimental part of the thesis tests the responses of two titmice species (Parus major and Cyanistes caeruleus), which have virtually no experience with cuckoo brood parasitism, to presented dummy of cuckoo adult. The visual appearance of the common cuckoo importantly resembles the Eurasian sparrowhawk (Accipiter nisus), and it is supposed that this similarity protects cuckoo from attacks of adult host birds. Thus I tested the theory that titmice mistake the cuckoo for the sparrowhawk, which affects their nest defence behaviour.
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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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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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Role znaků a geonů v rozpoznávání predátorů netrénovanými ptáky: obrana hnízda
NOVÁKOVÁ, Nela
I examined two main hypotheses proposed for the object recognition: Particulate feature theory and recognition by components using methods of behavioural ecology, namely nest defence. We tested reactions of Red-backed shrike (Lanius collurio) to dummies of Common kestrel (Falco tinnunculus) with scrambled body parts (head above, in the middle and at the bottom). Our result suggested that birds don't recognize the kestrel in the dummies with inappropriately placed head. Therefore, our results support rather the theory recognition by components.
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How the red-backed shrike (Lanius collurio) recognizes enemies
NĚMEC, Michal
This study investigates two questions about anti-predator behaviour of the red-backed shrike. 1) Is the red-backed shrike able to assess the differing dangers represented by various types or species of predators? 2) How does the red-backed shrike recognize the predator? We found, that the red-backed shrike (Lanius collurio) adjusts its anti-predator behaviour by assessing the potential threat to themselves from different predator species and by assessing the chance of a successful attack. Further, we found that the presence of general raptor salient features is absolutely necessary for proper categorisation of the intruder as a predator, whereas the natural species-specific colouration in itself is an insufficient cue.
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Which information is included in the alarm call of Red-backed Shrike \kur{(Lanius collurio)}?
MINAŘÍK, Tomáš
The first complex study of the alarm vocalisation of the Red-backed Shrike (Lanius collurio) is presented. Following on from previous studies five stuffed dummies ? Eurasian Sparrowhawk (Accipiter nisus), Common Kestrel (Falco tinnunculus), Eurasian Jay (Garrulus glandarius), European Magpie (Pica pica), and Common Wood Pigeon (Columba palumbus) ? were used to elicit antipredation behaviour. Seven different types of alarm calls are described ? besides the commonly used ?chak?, five mobbing calls and one that possibly warns conspecifics.
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