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Body size in reptiles: proximate mechanisms and ecophysiological correlates
Starostová, Zuzana ; Frynta, Daniel (advisor) ; Gvoždík, Václav (referee) ; Sedláček, František (referee)
Body size is a fundamentaltrait determininga suite of morphological, physiological andecologicalcharacteristicsoforganisms.The thesisdealswith topicscloselyrelated to proximate mechanisms of body size change in lizards and with ecophysiological correlates of body size such as metabolic rate and influence of environmental temperature.The Ph.D. thesis contains a brief introductorychapterand four chapters representedby threepublished or acceptedpapersand one submittedmanuscript.All papers included in the thesis have in common that they take into the account phylogeneticrelationshipsamong studiedspeciesand usedifferent methodsto control the effect of phylogeny. The first chaptershows thatevenwithin closely relatedgroup of lizards from the family Eublepharidae(eyelid geckos),thered blood cell size differs considerably and is conelated with body size. The cell size supposedly played an importantrole in evolutionary changesin body size in this group. The secondchapter is focused on evolutionary changes in genome size in eyelid geckos and on the relationship between cell size and genome size. The changes in genome size correspond well with phylogenetic relationships among eublepharids, but are independent on evolutionary changes in cell size. At higher taxonomic levels a positive correlation between genome...
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Foraging and reproductive strategies of selected passerine birds
Kryštofková, Milena ; Exnerová, Alice (advisor) ; Sedláček, František (referee) ; Šálek, Miroslav (referee)
According to currently generally accepted model of evolutionary optimalization of parental investments, parental behavior should be balanced to bring the highest benefits (maximal expected value of progeny) with the lowest costs invested. This necessity establishes the pressure, which forces the organisms to balance their life-history strategies according to the changing environment. More than one solution frequently exists, and it may be crucial, which one is chosen in a given circumstances. This Ph.D. thesis deals with three passerine species and investigates their foraging, reproductive and antipredatory strategies, in the framework of "costs and benefits" theory of parental decisions and also in association with the phenomenon of synurbization. The paper by Kryštofková et al. (2006) "Parental foraging strategies and feeding of nestlings in Common Redstart Phoenicurus phoenicurus" inquires whether such factors as age of nestlings, their number, or sex of parents have influence on parental feeding frequency and foraging strategies (parameters of hunting in space and time); the literary data are controversial, even for one and the same passerine species. The male uses passive foraging mode more than female and as the nestlings grow older, the proportion of passive foraging mode is increasing, while...
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Structure and function of selected lipocalins and their role in chamical communication in mammals
Stopková, Romana ; Stopka, Pavel (advisor) ; Sedláček, František (referee) ; Žídek, Lukáš (referee)
Sunrulnv or Pu.D.rHnsrs Chemical communicationis facilitated by various substancesand occurs in all organismal forms from cellular to multicellular organisms. This system of communicationspecializedduring evolutionand incorporatedspecificmeansof transferanddetectionof signalsincludingolfactoryreceptorsanddiversificationof specifictransportersof thesemolecules.Amongtransporters,lipocalinsareproteins thatdueto theirspecificbetabanel formingtertiarysffucutrehavehighafinityto bind various volatile ligands for which they have importantrole in chemical communication. MajorUrinaryProteinsarea well knownexamplein miceaswell asOdorantbinding proteins.However,thereare otherlipocalinsin this proteinfamily of which the function is as yet understudied.In my Ph.D. disertation,I aimed at detailed understandingofthe variabilityin lipocalinfamilyandto suggestotherpotentialroles of theseleastknownproteins.I am presentinga reviewpublicationstemmingout of my bio-informaticanalysis,one paperon Major Urinary Proteinsin two speciesof mice and a paperthatis now submittedand which dealswith novel lipocalin (Obp) genes in Myodes glareolus similar to afrodisin - a protein that was previously describedonly in hamsters.This paperis basedon the sequencesthatwereanalyzed and submittedto GenBank.This last resultopenednew streamof...
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Ontogeny of personality or repeatability in behavioral and cognitive tests
Pšeničková, Eliška ; Landová, Eva (advisor) ; Sedláček, František (referee)
Individual stability is important for the development of personality, and above all two patterns of consistency - structural and differential. The main goal of this diploma thesis was to monitor changes in the repeatability of behavior over time (i.e., differential consistency) during ontogenesis and to compare the consistency of selected elements of behavior in behavioral tests and a selected cognitive test. Testing of a model species of squamate reptile, the common leopard gecko (Eublepharis macularius), in standard behavioral tests and in a selected cognitive test across ontogenesis over three life stages (juvenile, subadult and adult phase) showed, after statistical examination, high estimates of repeatability and significant influence of ontogenetic phase. Behavioral consistency between juveniles and adults could increase or decrease for certain behaviors or remain consistent in only one phase of life. In the subadult period, the behavior was generally inconsistent, except for vocalization in the reactivity test, where it was demonstrated by high estimates of repeatability. The aim of testing in the selected cognitive test was to determine the non-cognitive component of variability, which could be explained by different personalities. Yet, cognitive styles associated with personality have not...
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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...
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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...
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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...
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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...
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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...
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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...
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