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Can the capercaillie (Tetrao urogallus) reintroduction be successful?
Stelšovská, Lenka ; Křenová, Zdeňka (advisor) ; Reif, Jiří (referee)
The western capercaillie (Tetrao urogallus) used to be a common species in Europe but, during the last decades, the species declined rapidly in the western part of its range, i.e. in Central and Western Europe. Decreasing of the habitat quality, inappropriate forest management, climate changes, disturbing by humans (sport & tourisms) together with very only low adaptabity of this species were recognized to be the most important factors threatening Tetrao urogallus. Also predation is a very important stress factor. Numbers of reintroduction projects have been conducted in Europe to improve the situation. This study summarizes current knowledge about reintroduction projects and their effectivity. Most of the projects were not successful very much. Reintroduction projects were implemented also in the Czech Republic in 1998 - 2007 and capercaillies have been released in several regions (Šumava, Český les, Krkonoše, Jeseníky, Moravskoslezské Beskydy, and Brdy). No new populations were established. The reasons for the failure have been found in the insufficient quality of the biotopes, predation, the physiological and ethological deficiencies of the young birds and the ways of their rearing. It is possible to summarize, that the reintroduction projects seem to be low effective but they are not completely...
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The importance of woodlots for birds in farmland
Rajmonová, Lenka ; Reif, Jiří (advisor) ; Zasadil, Petr (referee)
One of the outcomes of agricultural intensification is landscape homogenization, particularly obvious in developed countries. Unproductive plots of woody vegetation may represent a refuge for many species within large blocks of open areas. Eventhough it is crucial to assess the importance of such plots for animals in farmland, surprisingly, no synthesis on this topic has been published up to now. Therefore, performance of such an assessment is the main task of this bachelor thesis which is focused on birds since they heavily suffer from agricultural intensification. It was found that marginal vegetation provides not only habitat for breeding and foraging but also ecological corridor for birds᾽ short-distance movement and stopover sites for long-distance migrants. The structure of avian community is affected by specific characteristics of vegetation itself considerably and also by characteristics of landscape in smaller measure. Both farmland and forest birds occur in marginal vegetation, each of these bird groups utilizes these plots in a different way based on its ecological needs, however. The understanding of these mechanisms will allow effective conservation of biodiversity and restoration of once devastated areas. The main goal of conservation should be to ensure heterogeneous landscape mosaic...
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The impact of climate and land-use changes on birds
Koschová, Michaela ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee) ; Musil, Petr (referee)
Climate changes associated with increasing global temperature affect bird species. As a result, breeding ranges of European bird species will probably shift in future. Although it is unclear whether these shifts will come true, we can already see patterns recent bird population trends consistent with the impact of the changing climate. The results of our first analysis based on large-scale monitoring data showed that species with more northern latitudinal distributions had more negative population trends in the Czech Republic. Climatically induced shifts of species' geographic ranges can also provide important information about the potential future assembly of ecological communities. For this purpose we calculated the potential shifts of breeding ranges of European birds and explored their relationships with ecological variables to detect which ecological groups of birds will be most likely forced to move their ranges. Breeding habitat type showed the strongest relationship with the potential range shifts. The magnitude of the shifts can be considered as a measure of the climate change pressure on species. From this perspective, it is interesting to ask how these shifts relate to current species' population trends. Therefore we related the potential shifts to the long-term population trends of...
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Bird communities in stands of non-native trees
Hanzelka, Jan ; Reif, Jiří (advisor) ; Hořák, David (referee) ; Šálek, Miroslav (referee)
6 Abstract This thesis deals with the effects of non-native tree stands on birds in the Czech Republic. Non-native plants, including trees, are known to adversely affect the biodiversity. At the same time, birds represent a widely used biodiversity indicator. The studies of bird communities in stands of non-native trees presented here show the extent to which the birds have been impacted by non-native tree stands. This knowledge can be used to evaluate the importance of non-native plants as a biodiversity threatening factor. As the representatives of widespread non-native trees, the broad-leaved black locust and coniferous black pine were selected. In these stands I investigated possible mechanisms affecting bird communities, arising from assumed differences in vegetation structure, bird species richness, bird community composition, food supplies, and nest predation pressure compared to the stands of native oak and native Scots pine. In general, the bird species richness positively correlates with the vegetation structure complexity. Despite the fact that the non-native stands proved to have a higher heterogeneity of vegetation structure than the native stands, bird species richness did not differ among the focal stands. The bird community composition was primarily affected by the birds' preference of...
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The role of high-altitude habitats for speciation of central European endemics from the genus Campanula
Folbrová, Magdaléna ; Šemberová, Kristýna (advisor) ; Reif, Jiří (referee)
Mountain environment plays an important role in plant's life. Extreme conditions lead to continuous speciation accompanied by a complex processes e.g. geographical isolation (variation) or polyploidization. These processes can be studied by using a suitable model plant, represented in this thesis by selected mountain endemic bellflowers species belonging to Campanula rotundifolia agg. These species appear to be morphologically very similar but they are supposed to be of different origin. Mountain ecosystem is considered to be one of the most diverse and the most valuable environment for nature conservation. It hosts many endangered plants as well as plants protected by law. From the model group, these plants are represented by Campanula bohemica Hruby, Campanula gelida Kovanda and Campanula rotundifolia subsp. sudetica (Hruby) Soó. This thesis aims to sum up the up the current knowledge about a high altitude environment and endemism and to give a description of speciation mechanisms leading to the variability of mountain Campanula species. Further descriptions of their endangerment level, conservation and origin are also given. The subsequent MSc Thesis, introduced in the last part of this thesis, aims to reveal the origin of Czech and Slovakian mountain Campanula endemics. It is mainly focused on...
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THE EFFECT OF AN INCREASING COVERAGE OF INVASIVE BLACK LOCUST ON BIRD COMMUNITIES IN FOREST STANDS
Kroftová, Magdalena ; Reif, Jiří (advisor) ; Ferenc, Michal (referee)
Biological invasions are one of the most important threats to global biodiversity and they were also found to negatively affect some bird species. Despite relatively large number of scientific studies dealing with the impacts of invasive plants on bird communities, their results are inconsistent, especially it is not clear how birds respond to increasing levels of expansion of invasive species in native species stands. Moreover, bird responses to plant invasions seem to depend on the ecological characteristics of individual bird species. This study contributes to elucidation of this problem; I investigated the impacts of black locust (Robinia pseudoacacia) invasion on bird communities in three types of forest stands with different levels of invasion: in stands containing solely the native oak (Quercus spp.), in partially invaded stands with different proportions of black locust and oak (mixed stands) and in pure black locust stands. Previous studies that examined birds in pure oak and pure black locust stands have found that they differ markedly in vegetation structure, but not in the total number of bird species. However, habitat specialists were associated with the oak stands, while generalists with the black locust stands. Therefore, I predicted that (1) the total species richness will be...
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Long-term population trends of birds in North America and Europe: a metaanalysis of existing studies
Říhová, Jana ; Reif, Jiří (advisor) ; Voříšek, Petr (referee)
Since the beginning of the last century there have been significant changes in the environment, farming and the landscape structure. Because birds are one of the longest- studied groups of organisms and are considered to be good indicators of environmental quality, it is advisable to relate environmental changes to changes in bird abundance. Understanding these relationships enables better and more accurate formulation of conservation plans and priorities, and therefore a large number of studies were dedicated to them. Although these studies achieved great progress in the knowledge of the most important factors that affect bird populations, their findings remained somewhat incomplete and fragmentary due to their limited temporal and/or spatial coverage. Therefore, it was not entirely clear which patterns are general and which are confined to some specific regional conditions. The fill this knowledge gap, I collected all studies on long-term trends in bird abundance in Europe and North America, which I was aware of, and made a meta-analysis of their results. Using linear mixed-effects models, I found a significant decrease in open-habitat species, probably as a result of agricultural intensification and abandonment of agricultural land. This pattern was consistent regardless of region or time period...
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Among-population variability in yellowhammer songs: causes and consequences
Bílková, Jana ; Petrusková, Tereza (advisor) ; Reif, Jiří (referee)
The inter-population geographic song variability can be found in many bird species. One of the most interesting types are dialects, characterized by sharp boundaries between populations of individuals sharing the same particular song type. Despite many years of investigation there is no satisfactory answer to the question how these borders persist over the years at nearly same sites. Distinctions between dialects allow recognition of males from different populations and could influence the territorial behaviour. Various habitats, however, degrade the sound differently; it is therefore possible that specific habitats are preferred by individuals with specific dialects. Both social interactions and acoustic properties of the locality could also be only secondary factors and the dialect distribution could be the result of the habitat distribution either in present or in recent past. In this diploma thesis, several hypotheses were tested on the example of Yellowhammer (Emberiza citrinella) - a songbird abundant in open land with simple song and easily recognizable dialects. The thorough data concerning the habitats and dialect distribution were obtained at the dialect borders at two localities in Czech Republic. The reactions of territorial males to both foreign and their own dialects were also...
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Predictors of global threat in bird sister species
Štěpánková, Klára ; Reif, Jiří (advisor) ; Storchová, Lenka (referee)
Despite the threat of extinction in many bird species, it still not sufficiently known what are the biological characteristics related to this threat. This thesis tries to answer this question by analyzing the database of sister species, when we compare the traits of the threatened and unthreatened species within each species pair. This pairwise comparison should benefit from factoring, out the effects of traits shared within a given pair of species. In my thesis I use a global threat level from the IUCN classification and I relate it to latitudinal position of species geographic ranges, migration strategy, body size, habitat type and diet. I always take into account the effect of geographic range size. The range size is, often considered during the classification of threat and can also influence and the effects of other traits. Results show, besides the trivial effect of range size, when species with smaller ranges have a higher degree of threat, that the migration strategy is the only trait significantly related to the degree of threat at the global scale. Species, migrating for longer distances were more threatened than species migrating for shorter distances, probably because the former face more frequently the risks encountering many different environments and regions.
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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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