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Sunbird foraging behaviour on flowers of Impatiens sakeriana
Sejfová, Zuzana ; Janeček, Štěpán (advisor) ; Fuchs, Roman (referee)
Although the Old World sunbirds are generally considered to be an ecological analogy of the New World hummingbirds, until recently it was believed that in contrast to hummingbirds, sunbirds perch while feeding. This opinion was largely supported by several studies, mostly from South Africa, describing adaptations of plants facilitating this behaviour. However, recent studies have shown that the Old World nectarivores hover while feeding in front of flowers more frequently than previously thought. We focused on a specialised West African pollination system of Impatiens sakeriana and the foraging behaviour of its two major pollinators, the Northern Double-collared Sunbird (Cinnyris reichenowi) and the Cameroon Sunbird (Cyanomitra oritis). Based on continuous monitoring in their natural habitat via camera systems, we evaluated factors influencing bird foraging behaviour on a flower, i.e. bird's decision whether to perch or to hover. Our results indicate that sunbird foraging behaviour choice depends on plant architecture, namely on the length of peduncles and pedicels. Surprisingly, weather affects pollinator's behaviour just slightly. The data also indicate that feeding and moving among flowers require less time if the bird hovers and therefore this behaviour is associated with higher flower...
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Faces recognition as a distinctive cognitive process
Fišer, Ondřej ; Fuchs, Roman (advisor) ; Pokorný, Šimon (referee)
Facial recognition has been a major scientific topic. What particular cognitive process is responsible for recognition was a great unknown. Now, scientists are most inclined to the theory of holistic facial perception that we perceive the face as a whole. For successful face recognition it is necessary to pay attention to individual components and their configuration. Thanks to this approach, a person is an expert on faces and can obtain many types of information from them in a short time. Behavioral and neurological evidence supported the theory of holistic facial perception. The main behavioral tasks that support holistic facial perception are three: part-whole task, face inversion task, and composite task. The first two showed that face recognition negatively affects both the manipulation of individual components and their configuration. The composite task then shows that we are not able to perceive individual parts of the face independently. Holistic perception in animals has not been unequivocally confirmed, but for animals the face is as important as for humans. Moreover, the possibility of applying holistic perception to objects other than faces is currently being pointed out. Holistic perception today appears to be a robust type of perception applicable to various stimuli that meet the...
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Individuality of a courtship in semi-feral horses (Equus caballus)
Boušková, Adéla ; Komárková, Martina (advisor) ; Fuchs, Roman (referee)
In most of the mammalian species the courtship is a very important event preceding the reproduction itself. In some species specific courtship strategies are well described, however, in horses they are not, although courtship may have a major impact on the reproductive success of the individual. In horses (Equus caballus), polygynous mammals with harem type of social organization, courtship naturally involved wide spectrum of behaviour, by contrast, under domestic conditions they almost do not occur. This diploma thesis addresses the courtship and reproduction in semi-feral and domestic horses, specifically Exmoor pony and Merens horse breed, and individual reactions of mares to the stallion in the breeding season. A total of 45 individuals were observed for 240 hours from February to June 2018. We assumed the similarity of courtship within particular couples, but the result of the statistical analysis was the opposite, a high variability in the behavioural pattern repeatability (ICC 0,235-0,832), which, however, did not correlate with individual mare characteristics, i.e. age (ρ=-0,194, p=0,472), parity (t=0,569, p=0,578) or postpartum estrus (t=-0,070, p=0,945). We also assumed that the mare, which would show aggressive behaviour to the stallion during the courtship, would end the courtship by leaving or...
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Social cognition in birds Testing under laboratory conditions
Vondráčková, Nikola ; Nekovářová, Tereza (advisor) ; Fuchs, Roman (referee)
The thesis focuses on avian social cognition and its experimental methods in laboratory environment. Social cognition is the ability to know each other based on individual experience. Perception, attention, reasoning, memory and communication are the necessary cognitive competence of social cognition. Some cognitive domains are exclusively in social cognition - for example communication, theory of mind etc. Species of birds living in social groups constitute the social environment in which individuals respond to each other. Research subject of this thesis consists of these social interactions. Emphasis is placed mainly on parrots and corvids. The aim of this study is to review methods which have been used in order to test social cognition as well as critical evaluation of these methods. Key words: social cognition, cooperation, competition, laboratory tests
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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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Evolutionary consequences of species specific learning strategies: importance of processes resulting in food aversion and special case of social transmission
Landová, Eva ; Fuchs, Roman (advisor) ; Komárek, Stanislav (referee) ; Sedláček, František (referee)
t t Summary This PhD. thesis contributesto the investigationof aposematism- the phenomenonexplaining occuÍTenceof warning coloration in nature. Aposematismis anantipredatorystrategyousuallybasedonpredatorlearning to avoid a noxious prey with a conspicuoussignal. However, not only particularaspectsof aposematicprey signalling (waming colour pattern, conspicuousness,unpalatability),but also predator'spsychologyleadingto avoidancebehaviouris animportantfactorin theevolutionof aposematism. The differentialspecies-specificresponseof nine speciesof our conrmon passerine birds to living aposematicprey (the ťrebug) and correspondingunderlyingvariationin predator'secolory requirements has beenstartingpointof thisPhD.thesis. The next partsof the presentthesishavebeenfocusedmainly on determinationof thesespeciesthat respondspositively (throughoutinnate biases,betterlearningor memoryetc.)to the warningsignalof aposematic prey. The diversity of psychological processes leading to avoidance behaviourin thesespecieshas beenassessed.Firstly, we investigateif the avoidancebehaviouris acquiredby learningor ifthe preyis avoidedon the basisof innatebiasesin severalspeciesof family Paridae. Thenwe focused onmodeof avoidanceleaminganddurabilityof acquiredbehaviourin model species(greattits).The changesin memoryfor...
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