|
|
Interspecific comparison of social learning of food aversions in tits
Mitlenerová, Barbora ; Exnerová, Alice (advisor) ; Sedláček, František (referee)
Social learning in animals is a frequently studied topic, including birds. Great tits belong to frequently tested passerine species in this context. For this experiment we have chosen another tit species as model birds - adult and juvenile blue tits (Cyanistes caeruleus) and coal tits (Periparus ater). We tested an effect of social information on discrimination learning between palatable and unpalatable prey. Red and green artificial prey items resembling shieldbugs with a mealworm glued underneath were offered to birds. One variant was palatable, the other was unpalatable, soaked in bitter substance. Experimental groups were allowed to observe a pretrained tutor of the same species choosing palatable prey variant and rejecting the unpalatable one. The birds were then subjected to an individual discrimination learning task with simultaneously offered palatable and unpalatable prey items. The control group was not allowed to observe tutor and learned only individually. On the following day, all birds participated in a memory test. We tested if social information has an influence on avoidance learning in juvenile and adult birds of both species. We found that both species of tits were similarly successful in discrimination learning and there was no difference in success in performance between adult...
|
|
|
Mice and Rats: Space, Smell and Methods of Detection
Kaftanová, Barbora ; Frynta, Daniel (advisor) ; Sedláček, František (referee) ; Špinka, Marek (referee)
The coexistence of humans and rodents lasts from the beginnings of the history of agriculture. Many rodent populations accepted to synanthropic way of life and as commensals accompany human societies until today. In the first study we wanted to find out, how the evolution of non-commensal rodent species, a Cypriot mouse (Mus cypriacus), was influenced by people. This endemic island species evolved on the Cyprus Island without presence of any mammalian competitors or predators. In last 10.000 years humans arrived on the island, bringing several mammalian species, which affected the environment markedly. A black rat (Rattus rattus) is now dominant species there and presumably it is an important competitor for the Cypriot mouse. We supposed that the mice should avoid its odour. Nevertheless the rats odour was preferred by the mouse, probably as an odour of phylogenetically related species. On the contraty, the odour of domestic cat (species, which is also widespread on the island), was avoided. In conclusion, the long-term isolation from mammalian predators did not affect the antipredatory reactions of the Cypriot mouse. Our next study was focuse on changes in behavioural strategies of different populations of mice: the main question was how the commensal way of life affects their exploratory...
|
|
|
Evaluation of hybridization effect on fitness of eyelid geckos (Eublepharis, Gekkota) by performance tests
Kohoutová, Tereza ; Frýdlová, Petra (advisor) ; Sedláček, František (referee)
An interspecies hybridization is usually viewed from two sides - either as mistakes in a reproduction resulting in decrease of a hybrids fitness (e. g. loss or decrease of viability and fertility) or as a mechanism helping animals adaptively respond to environmental changes resulting in higher fitness. Fitness is usually represented as a set of correlates. One of the correlates is an organism performance which is represented by a set of maximal values from measured physical activities. This thesis focuses on the evaluation of the endurance and the bite force for gecko species E. macularius and E. angramayniu, their interspecies hybrids and intraspecies hybrids to determine their performance. The results show differences in the bite force among each of the tested groups. E. macularius has the lowest bite force, while the highest bite force was measured in E. angramayniu. The bite force of interspecies hybrids is intermediate in comparison to the parent species. Nevertheless, intraspecies hybrids of large form and white form of E. macularius exceeds their parents in measured bite force. The variability in bite force suggests a positive effect of hybridization on fitness. The bite force differences between the large form and the white form of E. macularius support the hypothesis that there exist more...
|
|
|
Factors influencing effectiveness of aposematic signals against avian predators
Kuklová, Lucia ; Exnerová, Alice (advisor) ; Krištín, Anton (referee) ; Sedláček, František (referee)
This thesis focuses on various factors affecting effectiveness of aposematic signals against avian predators. Adult, wild-caught as well as hand-reared juvenile great tits (Parus major) were used as predators in the experiments. The thesis consists of the following four studies. In the first study, we compared the reactions of great tits from two geographically distant populations toward aposematic firebugs (Pyrrhocoris apterus) and their non-aposematic artificially made colour variant. The birds from the Bohemian population mostly avoided aposematic firebugs and attacked non-aposematic variant. Finnish birds, which lacked experience with firebugs from their natural environment, were less hesitant to attack both firebug colour forms. Although the Bohemian birds avoided the aposematic prey variant, they were not more neophobic than Finnish birds. We conclude that the geographic differences in reactions of the birds to aposematic prey can be explained by a different population-specific experience of the birds with local aposematic prey communities. In the second study, we compared effectiveness of two chemical defence strategies in leaf beetle larvae (Chrysomela lapponica) against great tits. The birds avoided larvae devoid of external secretions after the first attack, which indicates the presence...
|
|
|
Implication of snow leopard distribution, population dynamics and landscape genetics, and prey preference for its conservation in Nepal
Shrestha, Bikram ; Kindlmann, Pavel (advisor) ; Sedláček, František (referee) ; Červený, Jaroslav (referee)
This thesis deals with an endangered large mammal species - snow leopard, its distribution, population dynamics, landscape genetics and connectivity, trophic ecology and human-snow leopard conflicts in the Nepalese Himalaya (Sagarmatha National Park (SNP), Lower Mustang (LM) and Upper Manang (UM) in the Annapurna Conservation Area, during Wet and Dry seasons in 2014-2016. In the case of snow leopard study, we used data obtained from camera traps, scat's genetic analysis and monitoring of fresh pugmarks and scrapes while direct count method was used to study for its main prey, blue sheep and Himalayan tahr. In study 1, we assessed the determinants of habitat suitability of snow leopards using MaxEnt model and mapped the distribution of suitable habitat for snow leopards in Nepal. Altitude and Annual mean temperature are important common factors contributing to snow leopard habitat suitability within the area studied, which is indicated by both the percentage contribution of environmental variables and Jackknife test from MaxEnt model. Some other uncommon factors also seem to play a role, as they were important in at least one of the analyses. These were: distance from road, and precipitation of driest month but their importance has to be considered with caution. In study 2, we present our...
|
|
|
The effect of incubation temperature on cognition and brain cellular composition in geckos Paroedura picta
Polonyiová, Alexandra ; Němec, Pavel (advisor) ; Sedláček, František (referee)
The effect of incubation temperature on different morphological, physiological, cognitive and behavioral characteristics in reptiles is a well-studied topic, although the underlying mechanism leading to the differences between individuals incubated at different temperatures remains largely unknown. In this thesis I studied the effect of incubation temperature on cognitive abilities and the number of neurons and non-neuronal cells in the gecko Paroedura picta incubated at two different temperatures, 24řC and 30řC. The geckos were tested in two cognitive tasks with simulated predatory attack. 14-day-old hatchlings were tested in a Y-maze, while 6-months-old geckos were tested in an arena with shelters of different colors. After testing, the number of neurons and non- neuronal cells in several parts of the brain were estimated using the isotropic fractionator in selected individuals. Although incubation temperature did not affect the success in the cognitive task in hatchlings, it did affect the total time needed to find the shelter. This difference remained significant also in adult geckos. The number of neurons, which was used as a proxy for the information processing capacity of the brain, did not affect success in the cognitive tasks. However, absolute brain size correlated with success in the...
|
|
|
Interaction between hierarchy, personality traits and melanin-based colouration in pigeons (Columba livia domestica)
Vohralíková Houšková, Markéta ; Landová, Eva (advisor) ; Sedláček, František (referee)
An individual position in social hierarchy is the key mechanism, how an individual could gain a priority access to more quality food resources, find an attractive sexual partner to reproduce and find territory with low predation risk and maintain its fitness in total. Personality is supposed to be an important factor how an individuals keep their positions in social groups. The consistent individual variability in aggressive behaviour is closely related to the expression of melanin-based colouration and testosterone levels in blood. More explorative, aggressive, bolder and darker-coloured individuals are supposed to achieve higher dominance rank in social structures. But this prediction was barely tested. The main aims of this diploma thesis were: to find consistent individual variability in social and non-social context to confirm personality traits and to define connection between an individual variability in agonistic and explorative behaviour and melanin-based colouration in relation to social rank in experimental group of domestic pigeons (Columba liva f. domestica) under human care. Unfortunately, personality could not be defined and even more, there was no significant correlation between dominant position in social hierarchy and individual behavioural variability in social and non-social...
|
|
|
Category discrimination in avian predators: formation of natural categories of unpalatable prey
Zíková, Markéta ; Exnerová, Alice (advisor) ; Sedláček, František (referee)
Ability to categorize objects to classes and react to members of one class similarly is important for animals, for example to facilitate discrimination between palatable and unpalatable prey. Objects are typically categorized according to their common features. Birds mainly use visual perception and so their prey also signals its unpalatability visually, through aposematic coloration. We studied the ability of great tits (Parus major) to categorize prey into classes of palatable and unpalatable according to its appearance. Birds were divided to three experimental groups, each tested with different categories of prey. First group was trained to discriminate between aposematic species of true bugs (Heteroptera) and non-aposematic species from other insect taxa. Second group was trained to discriminate non-aposematic species of true bugs and species of other insect taxa and the third in discrimination of pseudocategories, consisting of randomly assigned stimuli from the first experimental group. Tested birds were wild-caught adults and naïve, hand-reared juveniles. Juveniles were tested only in first two experimental groups. All birds were first trained in discrimination between the two categories and then tested in a generalization test with new stimuli. Both adults and juveniles learned to...
|
|
|
Phylogenetic relationships and evolution of the genus Acomys (Rodentia: Muridae)
Palupčíková, Klára ; Frynta, Daniel (advisor) ; Sedláček, František (referee) ; Mazoch, Vladimír (referee)
The geographical distribution and phylogeny of the spiny mice of the genus Acomys Geoffroy I., 1838 remains a controversial and open topic. This doctoral thesis deals with the intraspecific structure and geographical distribution of the genus Acomys from the northern, eastern, central and southern parts of Africa, the Mediterranean islands of Cyprus and Crete, the Turkish coast, the Arabian and Sinai Peninsula and Iran, using molecular analyzes. Molecular analyzes were based on both the mitochondrial gene sequences of the D-loop genes (publication I.) and cytochrome b, as well as the nuclear sequences of the Intraretinal Binding Protein gene (IRBP) (publication IV) and recombinant activation gene 1 (RAG1) (publication II.). Furthermore, the data were subjected to phylogenetic analyzes using the Maximum Probability, Bayesian, Maximum Parsimony, and Minimum Evolution analysis. The results of mentioned analyses confirmed that the Afro-Mediterranean Acomys cahirinus and Asian Acomys dimidiatus are clearly separated. The large similarity between the haplotypes of continental Africa and the northern Mediterranean (A. cahirinus sensu stricto) supports the hypothesis that the ancestors of A. nesiotes, A. cilicicus and A. minous are very likely to spread as commensal populations, thereby challenging their...
|
|
|
Ontogeny of animal personality
Pšeničková, Eliška ; Landová, Eva (advisor) ; Sedláček, František (referee)
Personality, consistent differences among individuals in their behaviour across time and contexts is a popular topic that is being addressed in a large number of studies. However, there are not many studies describing the development of personality over a longer period of time. The most relevant factors for development are: mean-level consistency (also called normative consistency), differential consistency (also called repeatability), structural consistency, and individual stability. Personality is generally more plastic in juveniles, where behavior is often more intense, in the sense that they are bolder, more aggressive/active/explorative, and over time, as individuals mature, plasticity and intensity of behavior decreases. Adolescence is a period in which behavior is often restructured and thus is not stable and consistent at this life-stage. However, behavior does not necessarily change during ontogeny, it may remain unchanged, or the intensity of behavior may also increase with age. Selected models describing the ontogeny of the animal personality are not sufficient and new ones need to be formulated. These should include more variables, for example genetic or maternal factors. This work is a review of studies about ontogeny of animal personality. KEY WORDS: Personality, ontogeny,...
|
guest ::
RSS feed.