|
|
Programmes of monitoring of bird occurrence and abundance as a source of ecological data
Mourková, Jindra ; Fuchs, Roman (advisor) ; Reif, Jiří (referee) ; Bejček, Vladimír (referee)
5 regionálních atlasech (Flousek & Gramsz 1999, Hromádko et al. 2005), umožňuje lépe zachytit proměnlivost výskytu a početnosti ptáků, která je daná mozaikovitostí studovaného území. Kromě údajů o prokázanosti hnízdění v jednotlivých kvadrátech síťových map přináší také odhad početnosti v celém území CHKO, charakteristiku výskytu a prostředí využívaného druhem na daném území a údaje o hnízdních hustotách v různých typech prostředí. Kvantitativní mapy pro jednotlivé druhy nejsou bohužel dosud zpracovány. SUMMARY OF THE THESIS In the thesis, regional data on bird communities were studied in terms of species richness and occurrence of bird species in dependence on habitat and, in case of wintering birds, also on climatic conditions. The regional grid atlas of Prague (Fuchs et al. 2002), records from Wintering waterbird census in Central Bohemia, own data on the breeding population of the Mute Swan in the Třeboň region and data from individual marking of Mute Swans provided by the Bird Ringing Centre of the National Museum were used as the sources of data on the occurrence and abundance of bird species. The thesis also includes a part of the text of the prepared Atlas of breeding distribution of birds in the Třeboň region. The first contribution (Mourková J., Fuchs R., Sedláček O., Janovský Z., Exnerová A.,...
|
|
|
Marine magafauna of coastal waters in southern Ireland
Svobodová, Hana ; Petrusek, Adam (advisor) ; Reif, Jiří (referee)
Land-based observations may contribute to an overall understanding of behaviour of large marine vertebrates and may help us understand how these animals react to climate change. I observed marine megafauna (cetaceans, Basking shark, and Sunfish) from Cape Clear Island situated in the south-west of Ireland. The study took place during the summer months (June - August 2008) because the majority of Leatherback turtles, Sunfish and other megafauna species are sighted in Irish waters in this period. Additionally to sightings, basic weather characteristics were recorded (sea state, visibility, glare and cloud cover) every day of observation. Unfortunately, no Leatherbacks, my target species, were recorded during the study period (51 days) at Cape Clear. The reason for the turtle absence could be relatively cold and wet weather during the study period. Although no data was obtained on turtles, over 124 sightings of other megafauna were made, mostly cetaceans (five species) but also one individual Basking shark and several Sunfish. The species richness increased with time during the study period, and significantly higher number of individuals as well taxa was observed in the second month of the study when the sea surface temperature was higher. However, I did not detect a significant relationship of number...
|
|
|
The effect of climate change and land use change on the long-term population trends of birds in the Czech Republic
Koschová, Michaela ; Reif, Jiří (advisor) ; Voříšek, Petr (referee)
There are number of future projections of species' geographic ranges developed under conditions of ongoing climate change. However, only a few studies have assessed what are the characteristics of species explaining interspecific variability in the projected range shifts. Examination of such relationships is important for development of effective conservation strategies mitigating the effects of climatic changes. For this purpose, I calculated the predicted shifts of European ranges in Czech birds based on maps in A Climatic Atlas of European Breeding Birds and explored relationships between these predicted shifts and several ecological traits. We found significant effects of the type of European distribution and habitat requirements. Concerning the type of European distribution, the largest shift is predicted in the central species and the northern species compared to widespread and southern species. According to the habitat type, the largest shift showed forest birds in contrast to the urban species which will shift slightly. The former pattern is probably attributable to spatial constrains different among these specific groups (central species are less limited compared to widespread species). The latter pattern could be explained by higher sensitivity of forest species to climatic changes...
|
|
|
Trade-off between egg size and number at the level of bird families
Špaldoňová, Alexandra ; Hořák, David (advisor) ; Reif, Jiří (referee)
Trade-off between offspring size and number belongs to the most discussed concepts in the life history theory. The aim of this study was to elucidate the relationship between egg size, clutch size and female body mass at the family level in bird's and to examine whether there is the relationship between offspring size and number and life history traits specific for particular bird families. From published sources, I collected data about 5.073 species belong in 146 families. Most species of birds lay smaller clutches, on average three eggs. In 112 families from 130 tested eggs size was positively correlated with female body mass. There is evidence that egg size and clutch size are inversely related in 83 families from 130 tested but only for 34 families was significant. The relationship exists independently of female body mass across bird families and this suggests a trade-off between these traits. The relationship between the strength and shape of egg size-number correlations and life history characteristics of bird families was not frequent. According to results, the strength of correlation seems to be related to development mode and diet type. The negative egg size-number correlation is stronger when incubation period and fledging time is longer and in birds with longer lifespan. The...
|
|
| |
|
|
Industrial melanism in the context of ultraviolet reflectance
Stella, David ; Reif, Jiří (referee) ; Kleisner, Karel (advisor)
This work focuses on the topic known as industrial melanism. The main aim of this thesis is to summarize the knowledge published on this topic. The first mentions about industrial melanism appeared in England in the end of 19th century. Many different hypotheses emerged during the last one hundred years. The work starts with introduction of the fundamental theory of industrial melanism in the context of environmental change during last three hundred years. Furthermore, the historical development of ideas on industrial melanism is given and contemporary hypotheses are discussed. Significantly, work deals with the biological role of UV reflectance in the context of industrial melanism.
|
|
|
Factors influencing the ecological stability of the Novozamecky rybnik Reserve
Hanzelka, Jan ; Reif, Jiří (referee) ; Čihař, Martin (advisor)
Fishponds and their surroundings are affected by many factors disrupting their ecological stability. In this thesis, influences of selected factors are evaluated. Particularly it is discussed excessive overgrowing of shoreline by plants, pond siltation by allochthonous material from catchment area, eutrophication process and intensive fish farming. It is presented the impact of these factors on local avifauna in Novozámecký fishpond National Nature Reserve and Special Protection Area and compared with Třeboňsko Special Protection Area. Birds use the ponds especially as nesting habitat and food source. Therefore, it is necessary to describe the influences disrupting this habitat. The frugal interference with mentioned processes is needed in terms of dynamics of the ecological stability. Thereby the requested fishpond parameters and ecological and economic values will be maintained. Fisheries management and lack of historical management in the form of reasonably performing mowing and grazing in the vicinity of the ponds has the greatest impact on the habitat of birds upon Třeboň fishponds. Novozámecký pond also suffers from the lack of historical management, but the unsatisfactory state of the pond is rather due to the overall eutrophication of the environment.
|
|
| |
|
| |
|
| |
guest ::
