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Environment and avian song: case of South African birds
Mikula, Peter ; Albrecht, Tomáš (advisor) ; Linhart, Pavel (referee)
Relationship between animal signalization and environmental conditions, where these species are living, is one of crucial topics of ecology. Using two complementary statistical approaches (fourth-corner and RLQ analyzes) I investigated geographical variation in parameters of bird vocalization in South Africa (RSA) and Lesotho. Altogether, I used nine quantitative and five qualitative acoustic traits for 472 bird species and nine environmental variables which could significantly influence parameters of their vocalization. My results supported findings of previous studies about the important effect of body size on species-specific vocal characteristics. In passerines, analyzes corrected for body size showed that the number of elements and element types were increasing with variability of natural conditions and were highest in very arid and climatically unpredictable areas. Element and element type rate were positively associated with altitude. Minimal song frequency in passerines and frequency range of vocalization in other birds were negatively correlated with average temperature of warmest and coldest month of the year, respectively. Similarly, environmental variables significantly influenced distribution of several qualitative song traits in passerines. Passerines, where female song and...
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Effect of body-margin shape on detectability of cryptic prey
Machalková, Kateřina ; Exnerová, Alice (advisor) ; Hotová Svádová, Kateřina (referee)
5 Abstract Subject of many studies dealing with interactions of predator and prey is behaviour and reactions of those predators who distinguish their prey by visual signals. The aim of the study was to compare the detectability of prey with a simple or structured body-margin shape of cryptically coloured true bugs Dysodius crenulatus and Dysodius lunatus (Aradidae) using a different type of background (tree bark of Acer, Gleditschia and Tilia). Background photos were presented in black and white and colour. The test was performed on naive birds and on the wild-caught adults of the Great Tits (Parus major) and the Blue Tits (Cyanistes caeruleus). The experiment was performed in the experimental cage with one-sided mirror glass. The influence of the body-margin shape of the prey was evident for certain groups, but the effect was depending on the age and specie of the birds and the type of the background. Different times of the search for prey were encountered as it was more difficult for birds to search for structured body-margin shape and the birds found faster preys with simple ones. When searching on the colour background the Great Tits were faster than on black and white background. Naive birds of the Great Tits were in search of prey faster than adults and vice versa with the Blue Tits. A separate task...
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Environmental determinants of bird species richness and population densities in sub-Saharan Africa
Dubský, Marek ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
The research of factors influencing bird's species diversity and abundance will allow us to manage the landscape in the way to create suitable conditions for survival of species. For the purposes of this work, I divided bird assemblages into 3 groups on local level: forest birds, shrubland birds and grassland birds. The forest bird species were most influenced by height of canopy, its compactness and fragmentation of the forests. The size of the fragment, fragment matrix, isolation of the fragment and birds sensitivity to edge effect were deciding factors of number of species and individuals in each fragment. The shrubland birds were most influenced by vegetation structure in meaning of presence of shrubs, trees and grassland. They were also influenced by vegetation species composition, frequency and form of disturbances (fire, grazing), they reacted positively to transformation of landscape into agroecosystems and they reacted negatively to shrub encroachement. Grassland birds reacted to various height of grass, they reacted negatively to presence of trees and shrubs and also to disturbances caused by human. It is the least studied group of birds in Africa. As fot the elevation gradient, the lowland assemblages of birds changed to mountains assemblages at attitude of about 1250 above the sea...
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Tool use in birds
Skoumalová, Žaneta ; Exnerová, Alice (advisor) ; Nekovářová, Tereza (referee)
Tool use has been observed in many bird taxa, mostly in parrots and songbirds. Tools are primarily used for a purpose of food acquisition and food preparation and physical maintenance. Spontaneous tool manufacture or tool use has been observed in species, which do not use tools in the wild. Tool using is actively performed only by those birds, whose natural environment has a reduced food availability, food is difficult to extract and handle. Tool manufacturing and tool using requires a considerable degree of cognitive abilities, which are experimentally tested in tasks involving use of tools. Differences between species that use tools in the wild, and those that do not are manifested not only in solving experimental tasks, but also in how birds acquire the ability to use tools. While tool users often solve tasks successfully by using causal reasoning, non-tool users are not always capable of solving complex tasks and understanding of the physical properties of the situation. Negative results of these species do not necessarily imply a lack of understanding, but they can also be caused by morphological or environmental constrains, which make tool use more difficult. Tool users also have inherited behavioral patterns, which are further strengthened by individual learning and can be influenced by...
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Bird and Mammal Taxidermy
Tuzová, Lucie ; Řezníček, Jan (advisor) ; Štěpán, Jiří (referee)
This thesis deals with the preparation of dermoplastic materials of birds and mammals. They are described in detail specific methods of preparation from the collection of material to its final treatment. The first section summarizes the theoretical knowledge concerning preparation of dermoplastic models and osteological material. The second part is dedicated to knowledge survey of high school and primary school students concerning recognition of birds and mammals dermoplastic models. The results are processed by descriptive statistics. Keywords: taxidermy, dermoplastic models and osteological material, skulls, teeth, birds, mammals.
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Ecological and phylogenetic effects determining variation of growth patterns in amniotes
Stanková, Veronika ; Frýdlová, Petra (advisor) ; Vohralík, Vladimír (referee)
Growth is a process during which organs or the whole body enlarges. It can be modeled by using growth models and curves. The work is mainly focused on the explanation of two types of growth - the determinate growth, which is finished after the reaching of the sexual maturity, and the indeterminate growth which on the other side continues even after the reproduction or after the reaching of the sexual maturity. In the literature there is generally stated that birds and mammals are characterized by the determinate growth, amphibians and reptiles have the indeterminate growth. The aim of this work was to analyze the current available literature relevant to the growth and to evaluate the above mentioned statements about the growth of the vertebrates. The ecological and the phylogenetic effects influencing the growth, the physiological regulation and the mechanism of the growth are summarized in this work. Powered by TCPDF (www.tcpdf.org)
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Taxidermy of the birds and mammals
Ouřadová, Petra ; Řezníček, Jan (advisor) ; Mazalová, Jana (referee)
The main subject of this thesis is the taxidermy. The taxidermal mounts will be used as a teaching tools in teaching practice. The thesis is a comprehensive guide for creation of the taxidermal mounts of birds and mammals. There are described both old and modern methods of taxidermy in this thesis. Thesis is enriched with news from contemporary foreign literature. The result of thesis is 8 mounts (6 birds, 2 mammals) which will use as teaching tools during teaching of biology. Key words: taxidermy, preparation, bird, mammal, teaching tool
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Abundance-distribution relationship: the importance of ecological specialization
Farkač, Jan ; Hořák, David (advisor) ; Reif, Jiří (referee)
6 Abstract The relationship between local abundance and regional distribution is a widespread ecological pattern. It is frequently reported to be positive, however exceptions have been evidenced. But the explanation is not clear at all. There are many of mechanisms explaining this relationship, from those related to statistical issues, those explaining it by metapopulation dynamics, to rates of ecological specialization, which are the most frequently considered. But it is likely that certain mechanisms work together. One of the principal hypotheses is the resource breadth hypothesis, which claims that generalists tend to be more abundant and widespread whereas specialists occur in small range and less abundant. There are two ecological relationships linked to ecological specialization. It is a niche breadth-range size relationship and niche breadth-abundance relationship. While the former is well documented, the information about latter is rather scarce. This thesis sums up existing studies about distribution-abundance relationship with a special focus on importance of ecological specialization. Key words: geographical distribution, local density, niche breadth, ecological specialization
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Ecological links between morphology and habitat selection in passerines
Bovšková, Denisa ; Hořák, David (advisor) ; Klvaňa, Petr (referee)
The thesis is focused on relations between avian morphology and habitat selection. This is a summary of comparative studies, dealing this problematics in closely related groups of passerines. Generally, we can classify species to two main groups according to habitat preferences. Aerial species have longer wings probably as a result of adaptation on move in the air and open spaces. In contrast, ground species have generally longer legs as adaptation for running on the ground and pedal locomotion. Longer tarsi are also documented in ground species living in vegetation cover. Species which prefer tall vegetation have short leg probably for better move in branches. Less pronounced morphological differences further reflect habitat preferences at smaller spatial scales within habitat types mentioned above. In addition, some studies reveal that morphological variation reported frequently as reflecting adaptations to feeding preferences shows some links to environmental variation (substrate structure) independent of diet composition, such as bill morphology. Powered by TCPDF (www.tcpdf.org)
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Incubation behaviour of birds in polar regions
Hromádková, Tereza ; Pavel, Václav (advisor) ; Praus, Libor (referee)
The climate in the polar regions is so extreme that it has led to a big number of special adaptations in life and reproduction of local animals. However, the disadvantages are compensated by several important aspects like much lesser activity of preadtors, long sunny polar day and an abundance of nutriments during spring and summer. I tis no wonder that many species of birds have adapted their life cycle and migrate annualy thousands of kilometres to the polar regions in order to increase their chance of successfully leading out their offspring. Birds in these areas nest during the polar summer. Only one species of nesting begins already during the polar winter, i tis an Emperor Penguin (Aptenodytes forsteri) in Antarctica. The broods of birds nesting in polar regions are bigger in quantity in average and they also incubated longer then their conterparts in temperate and tropical. The main difference is the incubation rhythm adjusting mainly the extension of sessions associated with a reduction of recesses. The only exception are songbirds who leaves their nests frequently but only for a short periods of time. The information about the incubation behaviour of the most of the bird species of the polar regions are still very limited and incomplete. Therefore, bachelor thesis contains so far...
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