National Repository of Grey Literature 64 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Species traits and ecological conditions linked to bird colonisation of cities
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Human settlements are a novel habitat type and species must respond to its ongoing expansion. For effective conservation of biodiversity, it is important to understand the mechanisms underlying these responses. This thesis focuses on urbanization in birds, from both the individual and community perspectives. The aim of this thesis is to find out if there are any "pre-adaptations" in some bird species to be successful city dwellers or if all birds can potentially exploit the urban environment when local conditions allow. According to the reviewed literature, I conclude that the urbanization in birds is not a universal pattern, but there are some specific traits shared by most of the urban birds. The successful urban species are mostly omnivorous or granivorous, they breed in trees or in cavities and, they are often ecological generalists. They are sometimes represented by non-native species occurring in the cities all over the world.
The importance of woodlots and their ecological characteristics for birds in an intensively managed agricultural landscape
Rajmonová, Lenka ; Reif, Jiří (advisor) ; Šálek, Martin (referee)
Various types of woody vegetation are a key biodiversity refugee in intensively managed agricultural landscapes. However, the role of woodlots, representing an important type of such a vegetation, remains overlooked so far. Whereas the previous studies focused on the effect of their area, shape and isolation, consequences of variation in their habitat quality for biodiversity were not assessed up to now. This thesis is thus one of the first studies focusing on woodlots as a specific habitat for birds in agricultural landscape. My goals were: (I) to find out what is the bird community composition of woodlots in a Czech landscape, (II) to find out, what are the key habitat predictors of bird species richness and abundance in woodlots, (III) to describe differences in habitat preferences among various guilds and (IV) to formulate recommendations for conservational practice. I surveyed birds in 82 woodlots in an intensively managed landscape in Central Bohemia, Czechia, and measured variables describing woodlots' habitat quality together with woodlots' area, shape, isolation and types of surrounding land-use. I recorded numerous forest and non-forest bird species (57 in total), including some endangered farmland birds. The habitat variables showing significant relationships to bird community...
Bird population changes from a historical perspective: a case study from the Czech Republic
Szarvas, Filip ; Reif, Jiří (advisor) ; Koleček, Jaroslav (referee)
Numerous studies focused on the changes in breeding bird populations in the Czech Republic exist, however, these studies are based on data from 1980s onwards. Such studies investigate the effects of environmental changes on various bird groups defined by their ecological traits. Although these studies provided important insights into bird population drivers, considering the start of 1980s as a baseline for comparisons with the current conditions is questionable since the underlying drivers most likely acted for longer time. To bridge this knowledge gap, the goal of my study is to create a comprehensive dataset covering changes in bird populations over three time periods: 1950s/60s, 1980s and recent time (2014-2018) based on the memories of ornithologists who witnessed these times. The next goal is to establish whether the decrease of some species dates from the last 40 years, or whether it predates this period. The results of my study show that certain groups of birds according to their ecological requirements disappear from the Czech landscape faster than other groups. In the groups of species classified by their environmental requirements, the most rapidly disappearing are species bonded to agricultural landscape and urban species. According to the food requirements, the fastest decreasing are...
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...
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...
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.
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...
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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