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Hormonal control of male sexual behaviour in reptiles
Schořálková, Tereza ; Kratochvíl, Lukáš (advisor) ; Landová, Eva (referee)
The most important hormone affecting typical male sexual behavior in reptiles is testosterone, but also other steroid hormones such as dihydrotestosterone, estrogens or progestins may be involved in this regulation. According to the organizational-activational hypothesis testosterone acting during early ontogenic stage has an organizational effect on adult behavior and this behavior is triggered by influence of recent levels of hormones. Moreover, it was formulated the hypothesis on temporary organization of male sexual behvior that could change existing interpretations. Reptile reproductive strategies use to be classified according to gametogenesis and steroidogenesis as associated or dissociated reproductive strategies howerever, this division is rather artificial. This review summarizes existing knowledge of the hormonal influence of sexual behavior in reptiles, and comments the most common methods.
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Interaction between animal cognition and animal personality
Houšková, Markéta ; Landová, Eva (advisor) ; Šíchová, Klára (referee)
Personality is an important characteristic of individual variability which in some way restricts the full behavioural flexibility. Generally, it is not known, what is the relationship between environmental variability and variability in cognitive abilities of animals? More specifically, how this relationship impacts on the evolution of behavioural plasticity and the expression of animal personality. It is assumed that there is a correlation between the type of personalities and cognitive abilities but mutual causal relationship of this interaction is not yet fully understood. Proactive types of personalities in cognitive tests seem to be neophilic but slower in adapting to changes in the environment or in the analysing of signals with the changed meaning (reversal learning). On the contrary, reactive types of personalities are probably neophobic, they less risk and they are more flexible. However, it is questionable whether these behavioural types have an influence on cognitive abilities and how this influence manifests itself specifically to them. In this thesis, we will focus on whether and how different types of personalities are reflected in these cognitive abilities for each species and what is the methodology for testing these dependencies. Key words: animal personality, coping style,...
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Factors influencing worldwide zoo collections of lizards, snakes, turtles and crocodiles: effect of conservation status, body size and their attractiveness to humans
Janovcová, Markéta ; Landová, Eva (advisor) ; Komárek, Stanislav (referee)
There is a large number of species existing in the world; each year, however, the number of the endangered ones rapidly increases. Nowadays, captive breeding becomes an option for their survival in refugees. Sufficient population with satisfactory breeding management gives hope for survival to the endangered species (in mid-term) or even possible future reintroduction to their natural habitat. WAZA is currently the world's leading association of worldwide zoos and similar breeding facilities. Because these institutions operate as a network to facilitate the exchange of reared individuals, for conservation purposes, their captive populations may be seen as one large population characterized by its size, i.e., the total number of individuals. Such view is currently recognized by many conservationists as the so-called concept of Noah's Ark. The space on the Ark is limited, therefore it is needed to heed the characteristics of the species aboard to maximize the conservation potential. Many factors influence the presence of species in zoological gardens. Following previous studies we selected some factors that may be important, i.e., body lenght, taxonomy, and IUCN status. Analysis of these factors among the main reptile clades shall reveal the pattern of reptile composition in worldwide zoos. One of the factors...
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A test of "object permanence" in Paridae and effect of neophobia and individual explorative strategies on success in solving object permanence tasks
Marhounová, Lucie ; Landová, Eva (advisor) ; Sedláček, František (referee)
Object permanence (OP) is a cognitive ability that enables animals to mentally represent the existence of hidden objects even if they can not be perceived by senses. In humans, OP develops during six qualitative stages, in which the understanding of relationships between objects in space and time changes. Current research shows that primates, some carnivores and several species of birds also acquire various degrees of this ability depending on their social life and foraging strategies. Many studies of OP have focused on food-storing birds but yet only in the Corvidae family. Therefore we decided to test this ability in two species of the Paridae family, food-storing coal tit (Periparus ater, N=23) and non-storing great tit (Parus major, N=24) to find out which stage they can achieve and whether there is a difference between these species in relation to their caching ability. Our results suggest that food-storing coal tits search for completely hidden objects significantly better than great tits. Most of the great tits were not able to solve this task. However, the upper limit for both species is probably Stage 4 because coal tits probably solved OP tasks with more screens randomly or used alternative strategies rather than mental representation. Substantial interindividual variability in the...
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Animal phobia: fear or disgust?
Peléšková, Šárka ; Landová, Eva (advisor) ; Hocko Fajnerová, Iveta (referee)
Animal phobias are among the most common specific phobias. It is traditionally assumed that two basic emotions are involved - fear and anxiety, although recent studies suggest that disgust may also be important. Phobias and involved emotions are defined mostly by psychologists and psychiatrists. Their manifestations could be identified mainly on physiological level and are being researched using advanced medical methods (e.g. functional neuroimaging). The eliciting stimuli of arachnophobia, ophidiophobia etc. are specific animal, spiders or snakes. However the category of elicitors for disgust sensu lato is fairly extended. The etiology of these phenomena is explained from the perspective of evolutionary biology and presumes biologicaly significant selective pressures and common coevolution. The aim of this paper is to summarize information gathered so far, verify proposed evolutionary hypothesis about the involvement of disgust in the etiology of animal phobia and to evaluate biological relevancy of fear of animal stimuli.
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The influence of selected environmental and behavioral factors on the degree of sociality in the family Herpestidae
Poláková, Petra ; Landová, Eva (advisor) ; Mazoch, Vladimír (referee)
Sociality in mongooses (Heprestidae) is a frequently studied characteristic. It is not known which factors modulate the degree of sociality. There are hypotheses about influence of environmental factors (habitat openness, temperature, precipitation). In this thesis we tested the influence of these environmental factors, but we did not discover any relation. Yet we found a strong relation between versatility (ecological valence) and inhabited climate conditions. Sociality could be modified by reproductive parameters (adaptations in greater litter size, longer gestation period and longer lactation period). We discovered relations between sociality (number of individuals in a social group) and gestation period, sociality and lactation period and sociality and litter size. We used phylogenetical correlation and found that the relation between sociality and litter size is not significant. Greater litter size occurs in only one phylogenetical line; hence we consider greater litter size to be not a predisposition, but a result of transition to sociality. It is also not clear what is the ancestral state of sociality and used habitat on the base of the clade. Hypotheses say that the common ancestor of the mongooses was solitary and lived in a closed habitat, but based on our ancestral states reconstruction...
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Comparison of individual's performance in a discrimination tasks with respect to the hierarchy status
Kocourková, Zuzana ; Landová, Eva (advisor) ; Veselý, Petr (referee)
The ability to discriminate stimuli is the most tested cognitive task in pigeons (Columbia livia f. domestica) within up to now published experiments. Up to now, the influence of personality traits on discrimination has been poorly studied. This thesis looks into the differences in success between individuals and discrimination tasks, and analyzes factors including personality traits influencing the success rate. In this experiment, the total of 72 individual pigeons were tested in four linked tasks: 1) discrimination of black and white screen in the Skinner's box, 2) discrimination of black and white circle patch in the Skinner's box, 3) discrimination of black and white lid in a cage and 4) discrimination of reduced black and white stimuli, placed on a lid, in the cage. The criterium of success was set on 80%. In the Skinner's box, the task were passed by lower number of individuals (6% in first, 20% in second) in comparsion with the cage (48% in third and 50% in fourth). The tasks differed in environment and size of stimuli. It has been determined, that te tested subjecs were able to generalise in the Skinner's box, with an expception when the stimuli was reduced. While testing, all factors that might have influenced the success rate were observed. It has been proved, that the success rate was...
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Contribution of social dominance on performance in spatial cognitive tasks in pigeons
Janská, Iveta ; Landová, Eva (advisor) ; Sedláček, František (referee)
Diploma thesis generally compares individual success pigeons in spatial tasks of varying complexity (in a role that requires abstraction of visual stimuli representing spatial relationships on the touch screen using two different strategies and spatial search task the middle plate of a series of plates with different variants of location) with hierarchical status of males and group females. Specifically thesis compares individual success pigeons in spatial tasks of varying complexity. The hardest task requires a certain level of abstraction of visual stimuli representing spatial relationships using experimentally induced two strategies: mapping strategy or specific symbol association with a position in space. The role tests on the touch screen with the help of operant conditionings. Difficulty in various stages of growing, the last stage role does manage only some individuals. Conversely easier task in real space with a bird tasked with finding the midpoint between objects in different variants locations within the arena. The difficulty of the task is not growing, and it can solve some individuals who have not learned operant conditioning if the previous job. Performance in cognitive tasks could be affected by the hierarchical status of the animal in the group. Pigeons position in the hierarchy has...
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