|
|
Influence of urbanization patterns on the escape behaviour of birds
Dontová, Alena ; Mikula, Peter (advisor) ; Brlík, Vojtěch (referee)
Urbanization, i.e., the anthropogenic transformation of natural habitats into urban areas, has significant impact on the biodiversity. One of the key factors for successful animal survival in urban environments is the increase in their tolerance towards humans manifested by their decreased shyness. One of the field methods for assessing the level of the shyness across different individuals, populations, and species of animals is measuring their flight initiation distance. In this thesis, I focus primarily on birds, as their responses have been most extensively studied. Previous studies focused on differences in escape behaviour among birds mainly between urban and rural areas, and focused mainly on Europe and North America. However, human settlements vary in their history, size, population density, and other characteristics. Therefore, the observed patterns in bird behaviour may not always be universally applicable across all cities. In this thesis, through a literature review, I summarize how the escape behaviour of birds differs not only between urban and rural environments but also depending on the characteristics of human settlements, such as their size, history, degree of urbanization, the density of the local human population and the ecoregion. I found that the most important characteristics are the...
|
|
|
Vigilance and escape behaviour in ground squirrels (tribe Marmotini)
Milerová, Petra ; Vohralík, Vladimír (advisor) ; Matějů, Jan (referee)
In the ground squirrels, vigilant antipredator behaviour is frequently studied as a part of antipredator strategy. More vigilant animals have greater chances to avoid a predator attack. But it's also true, that animals allocating more time to vigilance, can allocate less time to foraging. There is obvious trade-off between vigilance and foraging. Ground squirrels, marmots and prairie dogs have to receive a lot of food to accumulate fat reserves for the hibernation period, and in case of juveniles also to ensure their growth. Therefore, they are forced to allocate time between aforementioned activities suitably. In view of the close relationship between vigilance and foraging, these two activities are often investigated together. The most important factors influencing aforementioned activities are number of simultaneously active individuals and presence of visual barriers. An affect has also age, sex and reproductive status of the individual or caloric content of the food. After the detection of a predator with the aid of vigilance, can be initiated escape response. Escape distance, escape velocity and escape behaviour in general are influenced especially by the type of predator, type of vegetation cover and individual distance from a burrow entrance. It is important that total energy costs of these...
|
|
|
Vigilance and escape behaviour in ground squirrels (tribe Marmotini)
Milerová, Petra ; Vohralík, Vladimír (advisor) ; Matějů, Jan (referee)
In the ground squirrels, vigilant antipredator behaviour is frequently studied as a part of antipredator strategy. More vigilant animals have greater chances to avoid a predator attack. But it's also true, that animals allocating more time to vigilance, can allocate less time to foraging. There is obvious trade-off between vigilance and foraging. Ground squirrels, marmots and prairie dogs have to receive a lot of food to accumulate fat reserves for the hibernation period, and in case of juveniles also to ensure their growth. Therefore, they are forced to allocate time between aforementioned activities suitably. In view of the close relationship between vigilance and foraging, these two activities are often investigated together. The most important factors influencing aforementioned activities are number of simultaneously active individuals and presence of visual barriers. An affect has also age, sex and reproductive status of the individual or caloric content of the food. After the detection of a predator with the aid of vigilance, can be initiated escape response. Escape distance, escape velocity and escape behaviour in general are influenced especially by the type of predator, type of vegetation cover and individual distance from a burrow entrance. It is important that total energy costs of these...
|
guest ::
