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Towards the understanding of agricultural intensification impacts on farmland birds: the effects of changes in invertebrate food supply
Hološková, Adriana ; Reif, Jiří (advisor) ; Lučan, Radek (referee)
Populations of insectivorous farmland birds recently underwent dramatic declines. Agricultural intensification is the main cause of these population changes, but involves numerous different mechanisms. Changes in food supply are thought to be one of the key factors. Homogenization of diet supplied to insectivorous chicks reduces their growth rate resulting in their smaller size as adults; decreased abundance of prey affects both survival and fitness of chicks and the overall breeding success. The accessibility of food is one of the most important factors limiting the use of food-rich habitats. However, the impact of all these factors on population trends has been shown in a single species - grey partridge. While the effect of changes in food supply on the breeding success has been confirmed in many other species, there is a lack of information on subsequent links to the survival of fledglings and the major causes of mortality outside the breeding period remain unclear. In general, there is insufficient information on population consequences of the changes in food supply for farmland birds, particularly in Central and Eastern Europe - the region with different characteristics from those we find in regions in which most of the findings were collected. Without this information, it is difficult to...
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Impact of Climate Change on Czech Bird Populations
Telenský, Tomáš ; Reif, Jiří (advisor) ; Morelli, Federico (referee) ; Gamero, Anna (referee)
Charles University, Faculty of Science Institute for Environmental Studies Doctoral study programme: Environmental Sciences Summary of the Doctoral thesis Impact of Climate Change on Czech Bird Populations Vliv klimatické změny na ptačí populace v České Republice Mgr. Tomáš Telenský Supervisor: doc. Mgr. Jiří Reif, Ph.D. Prague, 2018 Abstract Climate change is one of the most important drivers of biodiversity. If it proceeds at current pace, it will lead to homogenization and pose a serious threat to biodiversity. Birds, as one of the most researched taxonomic groups, are successfully used as indicators of biodiversity of the whole ecosystems, and thus offer an excellent opportunity to study the overall impact of climate change. We use data from repeated annual monitoring programmes in Czech Republic, Breeding Bird Monitoring Programe, based on point counts, and Constant Effort Sites mist- netting ringing programme, capture-mark-recapture schema. We found that: 1. Population growth of 6 out of 37 resident species responded negatively to seasons with lower winter temperatures. The response was stronger in species feeding on animals. 2. Long-distance (LD) migrants' breeding productivity responds negatively to higher spring temperatures and advanced spring as indicated by earlier leaf unfolding of three tree...
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Bird population trends in Eastern Europe
Fesenko, Valeriia ; Reif, Jiří (advisor) ; Šálek, Miroslav (referee)
Recently there are many studies that show differences in the development of the bird populations all over the Europe. Most of these findings are based on the data from the western countries in which is only a smaller portion of the population of the examined species. Eastern European countries are considered to be the centre of the European biodiversity, birds included. The objective of the thesis is to, using the form of recherche, describe the development of bird populations in the Eastern Europe and to compare it with the states in the Western Europe. It was found out that the trends of the numbers of birds, agricultural and forest landscapes in the Eastern Europe were less negative than it the Western Europe. At wetlands and water birds the differences in various regions and also more stable trends were observed in the Eastern Europe compared to the countries in the Western Europe.
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Ecological traits as a correlates of spatial variation in abundances of a Czech birds
Farkač, Jan ; Hořák, David (advisor) ; Reif, Jiří (referee)
Jan Farkač, Diplomová práce 2018 Abstract Bird species differ in their local densities, which seems to be related to their geographical distribution and species-specific traits. Investigating such a relationship can help us to understand better how the birds inhabit the space. The aims are as follow (i) to take an alternative approach to densities by counting them just in species preferred habitats and (ii) to explain the abundance characteristics such as an absolute density, variation in local densities or occupancy by species-specific traits. The relationship between abundance characteristics (local densities and their coefficient of variation in space) and avian traits such as a habitat specialisation, diet specialisation, PCA of morphological traits, PCA of reproduction traits - as an estimate of slow-fast continuum and a range size were tested using GLM. There are two abundance characteristics significantly related to species specialisation index. I have used the data from the Common Bird Monitoring Program run in the Czech Republic by the Czech Society of Ornithology. Due to the highest amount of records I have selected data from the year 2009 and subsequently species occupying more than 50 transects (out of 129), which resulted in inclusion of 47 species into analyses. This thesis contains...
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The impact of invasive plants on bird communities
Neubergová, Kristýna ; Reif, Jiří (advisor) ; Hanzelka, Jan (referee)
Invasive plants are among the major factors participating on the threat to biodiverzity. Birds are one of the Gross of organism endangered by this factor. However, birds provide a variety of ecological services and are often used as indicators of the state of enviroment in broker scale of landscape. Several researches assessing impal of invasive plants on ecosystem biodiverzity have been done, but none of them targeted bird communities specifically. Objective of this paper will be to anter free question regarding: (i) comparison of impacts of invasive woody plants and plants; (ii) comparison of impacts by type of enviroment in which the inavasive plant expanded (forest, grasses, island, wetlands); (iii) geographical area sof invasion. (i) The results indicie that from the perspective of bird communities, the negative impact of woody plants and plants was basically identical (76% for woody plants, 74% for plants). (ii) Comparison of impacts by type of enviroment in which the invasive plant expanded proved that the most severe negative impal of invasive plants was in islands biomes (100%), wetlands (91%), grassy biomes (87%). The lest severe impal was in forest biomes (63%). The results for island biomes was quite expected, as this biome is the most susceptible to disbalance of ecosystem. (iii)...
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Effectivennes of wader conservation
Mantičová, Mária ; Reif, Jiří (advisor) ; Kubelka, Vojtěch (referee)
The decline of many wader species (Charadrii) is globally significant, more than a quarter of species are at a certain level of threat. The decline in their populations is also a bioindicator of global problems, such as the water loss in the land. Waders are globally threatened by many factors, the most important are: habitat loss, changes in agriculture and higher predation pressure. The aim of my bachelor thesis was to create a background research on the effectiveness of protection of waders and to evaluate the impact of conservation actions on selected species. In most cases, they were agro-environmental schemes (AES), artificial creation and restoration of habitats, and active nest protection. The results of expert studies indicate that waders often occur at created or managed sites in higher numbers, but for overall recovery and increase of productivity of wader populations this is not sufficient in many cases. In the future, it would be necessary to extend globally those management measures that were essentially successful at particular locations and, in addition, to introduce further measures that are supposed to be successful despite the complexity of their implementation. Key words: waders, conservation, management measures, AES, threat
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Extinction risk and population size
Váňová, Lenka ; Storch, David (advisor) ; Reif, Jiří (referee)
There is generally accepted assumption that the probability of extinction risk increases with decreasing population size. But it's not sure at all, to what extent does this relation really work in real populations. The amount of studies dealing with this topic is on the increase, but still it's necessary to carry on researching. Previous results indicate that inspected connection is indeed true in many populations, in other words, preferential extinction of less abundant populations functions properly. Yet the dependence isn't as unambiguous and strong as expected. Many exceptions are known as well, which demonstrate that low number of individuals doesn't always have to be a disadvantage in terms of survival chance. Such deviations can be found both in paleontological papers and among current populations. For example, mass extinctions represent that kind of a special exception because each of them was probably driven by a different mechanism, so in one case the abundance could be an advantageous trait, whereas in another it was rather disadvantage. In my work, I briefly mention themes referring to extinction in general and subsequently I try to summarize findings about the phenomenon of population size and its connection to extinction risk. On the basis of explorers' ideas and by means of...
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Habitat as a determinant of abundance and distribution of birds in space and time
Reif, Jiří ; Storch, David (advisor) ; Fuchs, Roman (referee) ; Konvička, Martin (referee)
of the thesis The thesis focuses on various aspects of bird-habitat relationships. We found that the positive correlation between local abundance and regional distribution of birds is not a universal pattern. Its strength and direction depends on the similarity of habitat cover at the locality where the species abundances are measured and habitat cover of the wider region where the species distribution is assessed. In the case of the Cameroon Mountains, many locally abundant species had relatively small ranges in subsaharan Africa. They were probably well-adapted to specific conditions of montane environment, and such tight habitat association precluded their occurrence in regions covered by savannah or humid lowland forest. At the same time, isolation and unusual environmental conditions of the montane forest in the Cameroon Mountains reduced possibilities of their colonization by species widespread within Africa. Such species were confined to deforested areas in the Cameroon Mountains. The strongest gradient in bird community structure was between birds of montane forest and birds of non-forest habitats, and this gradient is probably one of the most important bird-habitat gradients worldwide. Endemic species and species confined to afrotropical mountains had the highest association with montane...
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