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Supplementations of the Mallard and their impact on wild populations
Pechmanová, Hana ; Musil, Petr (advisor) ; Kreisinger, Jakub (referee)
The Mallard (Anas platyrhynchos) is quite a popular game bird species. In many states, particularly in Europe and North America, captive-rearing and releasing of mallards has become common practice in wildlife management. The aim of these supplementations is to boost the size of hunted populations. More than three million Mallards are released each year. This paper aims to summarize and assess the potential effects of captivity-reared Mallards on the wild populations. Supplementations of mallards pose a threat to the genetic identity and variability of wild populations and may potentially lead to morphological and behavioral changes. Breeding facilities can be source of many pathogens, so supplementations may lead to transmission of these pathogens into wild populations. All the factors mentioned above may thus affect the fitness and population dynamics of wild Mallards. This paper also briefly considers how the releases can affect other species and the environment. This issue is not well studied so more studies and appropriate monitoring are needed for an assessment of the rate of these processes.
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Význam chovu Indického běžce
Kalivodová, Monika
The main purpose of this bachelor thesis was find out the importance of breeding an Indian runner duck. In this thesis I deal with the breeding and utilization of the Indian runner duck, and also with his history and extension. I also focused on the ancestor of the domestic duck, the wild duck. I have dealt with its hisotry, expansion and way of life. In this bachelor thesis, I also described what breeds of wild duck exist and are recornized in the Czech Republic.
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Spatial variability in population structure of wintering Ducks
Prokešová, Erika ; Musil, Petr (advisor) ; Hořák, David (referee)
5 Abstract This thesis is aimed at spatial variability of population structure of our four most common and the most numerous species of ducks wintering in the Czech Republic. These analysed species are Mallard (Anas platyrhynchos), Tufted duck (Aythya fuligula), Common Merganser (Mergus merganser) and Northern Goldeneye (Bucephala clangula). The field data were collected by January International Waterbird Census in the Czech Republic between 2004 and 2013. Analysed habitat variables include: type of wetland, altitude, population size, level of urbanisation (size of settlement) and mean January air temperature in the investigated site. There was found no significant effect of type of wetland and local population density on population structure in any of these bird species. The next factor, altitude of sites was confirmed as significant only for Mallards, when increasing altitude decreased proportion of males in the population. Furthermore, effect of urbanization was found also in Mallard, when proportions of males increased with level of urbanization, i.e. in larger cities. Finally, , temperature of sites was confirmed to be significant factor affecting population size in the three analyzed species, i.e. in Mallard, Tufted Duck and Northern Goldeneye. Except Common Merganser, ratio of males grew with...
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Supplementations of the Mallard and their impact on wild populations
Pechmanová, Hana ; Musil, Petr (advisor) ; Kreisinger, Jakub (referee)
The Mallard (Anas platyrhynchos) is quite a popular game bird species. In many states, particularly in Europe and North America, captive-rearing and releasing of mallards has become common practice in wildlife management. The aim of these supplementations is to boost the size of hunted populations. More than three million Mallards are released each year. This paper aims to summarize and assess the potential effects of captivity-reared Mallards on the wild populations. Supplementations of mallards pose a threat to the genetic identity and variability of wild populations and may potentially lead to morphological and behavioral changes. Breeding facilities can be source of many pathogens, so supplementations may lead to transmission of these pathogens into wild populations. All the factors mentioned above may thus affect the fitness and population dynamics of wild Mallards. This paper also briefly considers how the releases can affect other species and the environment. This issue is not well studied so more studies and appropriate monitoring are needed for an assessment of the rate of these processes.
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Management of wild mallard (Anas platyrhynchos) in the hunting ground Uhlířská Lhota (Central Bohemia, Czech Republic)
Malíková, Lenka ; Červený, Jaroslav (advisor) ; Nováková, Petra (referee)
The mallard (Anas platyrhynchos) is our the most widespread duck which occurs almost every water area. Her hunting is an essential part of hunting management in Czech Republic, but also in the world. As the numbers of mallards falling down, it is necessary to hunting management mainly focus on the care of the population of mallards. The aim of this study is to evaluate and describe the care of mallard in hunting Uhlířská Lhota. Because even in this hunting, members of a hunting association care of mallards is trying to increase their population. Hunting management is describing in this study in hunting Uhlířská Lhota for the years 2014 and 2015 when was found that mallard population status would most likely increase with increasing nesting opportunities and regular feeding, but predation and food competition is very high in that small water tank. Since the results of the catch for 2014 shows that there has been an increase in the number of mallards, but in 2015 to drop again.
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Analysis of selected aspects of the breeding biology of Great Crested Grebe (\kur{Podiceps cristatus})
MARKOVÁ, Kateřina
The aim of the thesis was monitoring abundance and distribution of nests of Great Crested Grebe (Podiceps cristatus) during the season on the Naděje fishpond system. Further observation included factors that could affect nesting success of the Great Crested Grebe. Attention was concentrated on Wild Duck (Anas platyrhynchos) which is bred by man on the fishpond system and might negatively affect nesting success of Great Crested Grebe. Part of this study was the detailed observation of selected pairs during the nesting season by using camera traps. Temperature measurement in the nests was done by temperature data logger. The investigation was realized on the Naděje fishpond system near the village Frahelž. The research took place from the 14th of April to the 28th of October in 2015. In 2015 were found and investigated 37 nests on the Naděje fishpond system. On the fishpond Skutek were monitored 34 nest, on the fishpond Láska 2 nests and on the fishpond Rod only 1 nest. Majority nests (30) were found on a free surface and 7 nests were situated in the bushy vegetation. Parameters of 111 eggs were obtained altogether. On the fishpond Skutek were found 100 eggs, on fishpond Láska 8 eggs and in the only nest on fishpond Rod 3 eggs. Using the camera traps during the observation proved negative effect of wild duck on Great Crested Grebe nesting. The nest was destroyed group of wild duck. The maximum temperature in the nest reached 33,8 °C.
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The influence of geomagnetism on the behavior of wild ducks
CHODIL, Josef
This work consists in an influence of the earth?s magnetic field to the orientation of the landing of wild ducks on a water surface. Some of the animal species perceive the magnetic field and they can use it for their orientation (migratory birds, bats, underground rodents, turtles and newts) Another variant of perceiving the magnetic field are the natural reactions (move tendency of cattle and deer at the pasturage, the orientation of carp in vats). Landing of wild ducks to a water surface is an unwilled reaction of perceiving the magnetic field. The material for this work was gained by the direct observation in nature. Observation was realized during the different terms of day and during the weather changes. The following data were written down: arrival, landing preparation, whole landing, wind power and the direction, weather conditions, disturbing influences, the position of sun, the distance of the bank during the landing. The analysis of acquired information proved the wild ducks prefer the southeast direction during the landing on a water surface.
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