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Biology of three-toed woodpecker
Navrátil, Martin ; Fuchs, Roman (advisor) ; Reif, Jiří (referee)
In my thesis I have tried to find out how does forest management influence presence of the Three-toed woodpecker Picoides tridactylus.This species is considered a "flagship species" of an untouched primeval type of forest and therefore it requires our attention and protection. The thesis contains results of North-American studies focused on the species very similar to Picoides tridactylus. The main chapters are those aimed to provide information about how is the Picoides tridactylus affected by forest fragmentation, stand health condition and finally the impact of food supply on the occurence and behaviour of the species.
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Surviving of Northern Lapwing (Vanellus vanellus) chicks in agriculture landscape
Kubelka, Vojtěch ; Šálek, Miroslav (advisor) ; Cepák, Jaroslav (referee)
The variability of egg-size within a bird species reflects different reproductive investments and, besides the intrinsic constraints and particular female quality, it can be affected by environmental factors, too. Moreover, the egg-size predetermines the chick performance. The knowledge of factors influencing precocial chick survival is crucial for better understanding of life-history strategies as well as for endangered species conservation. The Northern Lapwing (Vanellus vanellus) represents a suitable model species for investigation of climate variables effects on egg-size and also to study factors influencing chick survival. Eggs in a total of 714 nests were measured during 13 breeding seasons over period 1988-2014 in South Bohemia and 293 lapwing chicks from 100 broods in 37 localities were monitored in 2013-2014. The mean egg-size through the whole season is positively affected by March precipitation, March clutches also negatively by minus temperatures in March. The higher intensity of rainfall there is during March, the bigger eggs are laid in March and the steeper is slope of decline in mean egg-size during season. This decline is more profound with lower rainfall in April. The effect of habitat is not significant. The body mass and condition of hatchlings is positively correlated with the...
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Geopolitics of Global Food Supply - An analysis of Nigeria, China, and the United States
Eeg-Henriksen, Olav Mikael ; Riegl, Martin (advisor) ; Doboš, Bohumil (referee)
This thesis examines the functioning and implications of the food supply chain on countries food security by investigating one low, one middle, and one high-income country, represented by the Federal Republic of Nigeria, People's Republic of China, and the United State of America. While it is well understood that a high-income country has a more secure food supply chain than a low-income country, the multitude of reasons affecting this difference, and the severity of the difference is less clearly framed in literature. The first part explores and lays out the factors influencing all the key aspects of the food supply chain, and the second part then analyzing the selected countries through those. The third part explores some geopolitical trends of importance to the food supply chain. Through the analysis, the differences between the countries becomes apparent, and the results show a strong difference in food security for low income countries, compared to middle and high-income. The difference between middle and high-income countries is not as prevalent, but still meaningful.
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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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Surviving of Northern Lapwing (Vanellus vanellus) chicks in agriculture landscape
Kubelka, Vojtěch ; Šálek, Miroslav (advisor) ; Cepák, Jaroslav (referee)
The variability of egg-size within a bird species reflects different reproductive investments and, besides the intrinsic constraints and particular female quality, it can be affected by environmental factors, too. Moreover, the egg-size predetermines the chick performance. The knowledge of factors influencing precocial chick survival is crucial for better understanding of life-history strategies as well as for endangered species conservation. The Northern Lapwing (Vanellus vanellus) represents a suitable model species for investigation of climate variables effects on egg-size and also to study factors influencing chick survival. Eggs in a total of 714 nests were measured during 13 breeding seasons over period 1988-2014 in South Bohemia and 293 lapwing chicks from 100 broods in 37 localities were monitored in 2013-2014. The mean egg-size through the whole season is positively affected by March precipitation, March clutches also negatively by minus temperatures in March. The higher intensity of rainfall there is during March, the bigger eggs are laid in March and the steeper is slope of decline in mean egg-size during season. This decline is more profound with lower rainfall in April. The effect of habitat is not significant. The body mass and condition of hatchlings is positively correlated with the...
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Biology of three-toed woodpecker
Navrátil, Martin ; Fuchs, Roman (advisor) ; Reif, Jiří (referee)
In my thesis I have tried to find out how does forest management influence presence of the Three-toed woodpecker Picoides tridactylus.This species is considered a "flagship species" of an untouched primeval type of forest and therefore it requires our attention and protection. The thesis contains results of North-American studies focused on the species very similar to Picoides tridactylus. The main chapters are those aimed to provide information about how is the Picoides tridactylus affected by forest fragmentation, stand health condition and finally the impact of food supply on the occurence and behaviour of the species.
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