National Repository of Grey Literature 108 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Selected impacts of climate change on birds in European mountains: shifts in altitudinal distribution, population changes and changes in phenology
Mikulcová, Eliška ; Reif, Jiří (advisor) ; Hološková, Adriana (referee)
Many studies focused on the impact of the climate change on organisms including mountain birds. Mountain birds are particularly threatened by the impact of climatic change because they occur in an extreme environment. Climate change impacts mountain birds through increasing temperature, which affects their altitudinal shifts and abundances. These two variables depend also on species-specific traits, distribution area and habitat change. This thesis aims to sort knowledge about impacts of climate change on mountain birds and to explain the variability of altitudinal shifts of these species. Species occupying lower altitudes, open habitat species and short-lived species showed the biggest upward shifts. Downward shifts occurred when the impact of habitat change outweighed the impact of climate change. No significant shifts were recorded in species that respond to climate change by changes in phenology which likely compensate the adverse climate change impacts without the need of translocation. Population trends were usually negative with the steepest declines in high- alpine species, ecological specialists, long-distance migrants and short-lived species. In order to reduce decline in numbers, it is important to set up effective local vegetation management and globally stick to climate targets. Key...
Year-round specialists? Habitat niches of migratory birds on breeding and non-breeding grounds
Zálišová, Jaromíra ; Procházka, Petr (advisor) ; Reif, Jiří (referee)
Migratory birds undertake challenging journeys over vast distances each year to cope with seasonality in their environment and to exploit peaks in seasonal resources. The environments in which they are found in these geographically distinct regions over the course of the annual cycle vary considerably, forcing them to cope with a wide range of conditions. By examining whether migratory birds are year-round specialists that follow their niche or generalists that inhabit a broader range of habitats, we can better understand their ecology and the conservation implications associated with global change. However, our knowledge of habitat selection across seasons is still limited. This thesis aimed to explore and evaluate, through a literature review, existing knowledge on habitat selection by migratory bird species on breeding and wintering grounds. Emphasis was placed on the mechanisms influencing habitat selection, including geographical and anthropogenic influences, as well as to clarify the ecological requirements and potential specialization of migratory birds during their annual cycle. The current literature shows that migratory birds are most likely less opportunistic than previously thought, but a comprehensive analysis of data on habitat use by individual species is still missing and I would...
Pesticide impacts on farmland bird populations
Kutzendőrferová, Adéla ; Reif, Jiří (advisor) ; Grünwald, Jan (referee)
Pesticides are problematic chemicals that are found in a variety of environments. These substances tend to accumulate in living organisms, where they decomposite very slowly and can have a negative impact on bird populations. This is why some chemicals are still detected in these environments today, even years after their use has been banned, and may continue to affect organisms. The aim of my bachelor thesis was to conduct a literature search on the impact of pesticides on farmland bird populations. The first part of the thesis focuses on pesticides, their history, their division into different systems and their effects. The second part of the thesis then discusses the overall effects of pesticide use on farmland bird populations, particularly on breeding success and abundance. In this part, several studies have been collected that confirm the negative effect of pesticides on bird abundance, but not all of these studies are representative of real situations in the landscape. Finally, the paper assesses the overall role of pesticides in the observed bird declines and also presents suggestions to address the current negative trends. The thesis points to the need for expanded research studies that reflect actual conditions in agricultural landscapes to reveal the true extent of the effects of these...
Impacts of agri-environmental schemes on farmland birds in Central and Eastern Europe
Žid, Jeroným ; Reif, Jiří (advisor) ; Szarvas, Filip (referee)
Farmland birds have been decreasing for decades as a result of agricultural intensification. The EU tools for biodiversity protection are agri-environmental schemes (AES), the effectiveness of which has not been sufficiently studied in the countries of Central and Eastern Europe. To achieve high efficiency of AES and successfully protect farmland birds, it is necessary to collect the available information in this part of Europe. Among the most effective general measures are buffer strips of permanent vegetation (seed-rich strips, wildflower strips, hedgerows) but also the reduction of pesticides or fertilizers. Another type are targeted measures that are most appropriate for endangered species. When using an AES, it is necessary to consider both the territory of bird species and the impact of the given measure on individual species, as they often differ. Since the most used measures without targeting specific species have been effective, it would be appropriate to combine these measures to have the best possible effect on the birds. Newly, payments to farmers for applying AES are result-based, which is more efficient but it needs to be more attractive to farmers. To improve the Europe-wide farmland bird trend, it is important that many farmers get involved in the AES. Beside to the height of...
Dispersion and survival of Moorhen (Gallinula choloropus) in urban habitats
Vodičková, Barbora ; Musil, Petr (advisor) ; Reif, Jiří (referee)
Presence of Common Moorhen (Gallinula chloropus) in Prague is a long known fact. Mapping and data collecting of this species during winter is on a low level, so there is not many information about its winter behavior. Present climate change brings not only a change in climate, but in combination with rapid urbanization, also big changes in environment. Wintering locations are moving to the north due to higher temperatures, and also to the cities. This could be fatal for many individuals. Weather is unpredictable and during wintering season of 2016/2017 and 2017/2018 there were very unorthodox winter conditions, which had a significant impact on bird population in Prague. During winter 2016/2017 there were extermely low temperatures with median deep below zero degrees Celsius in combination with large snow coverage. Winter 2017/2018 was overall good for surviving. Reason for great decline in numbers was caused not only by climate and weather conditions, but also by wrongly chosen wintering location. Unique locality of Zoological garden of Prague in Troja district, offers safe shelter even during extreme weather conditions such as freezing cold temperatures. According to statistics , this location is best suited for survival. Keywords: wintering, Common Moorhen, weather, still waters, rivers,...
Population trends, threats and conservation of island endemic birds
Rohová, Kateřina ; Reif, Jiří (advisor) ; Sam, Kateřina (referee)
As endemics are considered plant and animal species including birds, which are in the focus of this thesis, that are found in a restricted geographic region and nowhere else in the world. Such endemics typically occur on the islands that are often recognized as important global biodiversity hotspots. However, many endemic species are very vulnerable due to numerous factors (mainly genetic and demographic) closely linked to the way of life on the islands. Huge effort is dedicated to their conservation, and it thus reasonable to ask whether such an effort made a significant contribution to prevent their loss. Here, I evaluate the overall success of island bird endemics conservation compared to continental conditions because such a global analysis has been lacking up to now. In addition, this thesis examines how three major threatening factors (namely habitat destruction, invasive species, and overexploitation) driven by anthropogenic activities affect population trends of continental and island bird species. Finally, I mapped and explained, using examples, which conservation tools are effective for supporting the populations of island endemic species. The results of statistical analyses, based on a global dataset containing almost 8000 avian species, showed that island endemic species are more...
Temporal changes in bird communities at the landscape level in Třeboň basin
Havelka, Jan ; Sedláček, Ondřej (advisor) ; Reif, Jiří (referee)
Population trends of birds are usually studied mainly on large national and continental scales or, on the contrary, quite locally. In an attempt to link these spatial scales, we repeated a quantitative survey of bird communities in the Třeboň Protected Area twenty years later (between 2001 and 2021). Bird counts were conducted during the breeding season on a fifty- kilometre transect (128 count points) intersecting a diverse range of habitats. We found declines in long-distance migrants and insectivorous birds compared to more stable or slightly increasing populations of resident species. Consistent with known trends, we also observed declines in populations of species tied to agricultural landscapes. Deviations from the well described trends by JPSP and PECBMS relate more to individual species characteristics. For example, we observed increases in populations of otherwise declining House Sparrow (Passer domesticus) and Field Sparrow (Passer montanus), or nationally stable Eurasian Siskin (Spinus spinus). Using detailed mapping of habitat and vegetation changes and other ecological characteristics of individual species, we have attempted to explain these general and site-specific changes in bird abundance and population trends. We were also interested in the manifestations of the generally...
Factors threatening European raptors and actions for their conservation
Žandová, Denisa ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Due to their visual appearance and general size, raptors are, among a general public, revered group of animals. This also, brings them more attention in sphere of animal conservation. Despite protection, which is given to them, raptors are among other birds severely endangered with their population decreasing in multiple places across Europe. The most frequent factors, which endenger raptors, are habitat loss, poaching, high-voltage powerlines, wind turbines and lead poisoning. This paper focuses on, describtion of methods of raptor protection, determination of efective protection measures, as well as determination of new useful solutions applicable for protection improvement. Studies has shown that in individual areas of Europe are endengering factors diferent than in others. Species with same ecological requirements and a way of life are endangered by same factors. The approach to these issues also changes depending on a country and some potential factors are not examined enough, yet. Thus it is of a great importance to spend more time on resolving these issues. Keywords: raptors, biodiversity conservation, risk factors, habitat loss, lead poisoning, poaching
Bird conservation status along a successional gradient in abandoned military areas
Bystřický, Václav ; Reif, Jiří (advisor) ; Hořák, David (referee)
Populations of open habitat bird species has significantly decreased in the Czech Republic during the last decades due to a number of negative factors, such as urbanization and intensification of agriculture. Due to the deterioration of the quality of these biotopes, a number of bird species (not only those of conservation importance) were forced to look for remaining fragments of favorable habitats, which are, for example, abandoned military training areas. The attractiveness of these territories lies primarily in their former closure for military purposes, which has protected these areas against these negative factors. In addition, army's activities created a heterogeneous landscape characterized by a mosaic of biotopes in different stages of vegetation succession - from bare ground, through grasslands, sparse scrubland, dense scrubland to the forest. However, the significance of abandoned military training areas for birds requires deeper investigation. The main goal of this thesis was to describe conservation importance of bird communities in individual biotopes along the successional gradient, for which a survey of 42 abandoned military training areas was used. The results of my work show that the most declining, endangered and protected species of birds sought out early successional habitats...
Long-term population trends in urban birds in Europe and Czechia
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Urbanization ranks among the most important processes induced by the human civilization that affects ecological communities at the same time. Birds are the most frequently studied organisms in relation to urbanization. Different birds' species show different abilities to adapt to urban areas, so urbanization works as an environmental filter. As urban environment undergoes extraordinarily high rate of change, the characteristics of the environmental filter are changing rapidly, too. This could influence populations of urban bird species. We can expect that the population change of the species will be related to the time since urbanization; specifically, the early urban colonizers will decline due to alteration of urban environment, while the recent urban colonizers will increase. I obtained data on population trends from 2000 to 2016 for 95 common urban bird species in 16 European countries. Thanks to the cooperation with local expert ornithologists, I collected the data about the time since urbanization of these species in respective countries and I related these two variables filtering out the influence of 9 other species-specific ecological characteristics. Bird population trends had a statistically significant relation to the time since urbanization: the species that became urbanized earlier...

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