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Long-term population trends in urban birds in Europe and Czechia
Grünwald, Jan ; Reif, Jiří (advisor) ; Sedláček, Ondřej (referee)
Urbanization ranks among the most important processes induced by the human civilization that affects ecological communities at the same time. Birds are the most frequently studied organisms in relation to urbanization. Different birds' species show different abilities to adapt to urban areas, so urbanization works as an environmental filter. As urban environment undergoes extraordinarily high rate of change, the characteristics of the environmental filter are changing rapidly, too. This could influence populations of urban bird species. We can expect that the population change of the species will be related to the time since urbanization; specifically, the early urban colonizers will decline due to alteration of urban environment, while the recent urban colonizers will increase. I obtained data on population trends from 2000 to 2016 for 95 common urban bird species in 16 European countries. Thanks to the cooperation with local expert ornithologists, I collected the data about the time since urbanization of these species in respective countries and I related these two variables filtering out the influence of 9 other species-specific ecological characteristics. Bird population trends had a statistically significant relation to the time since urbanization: the species that became urbanized earlier...
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The effect of urbanization on life-history strategies in birds
Houšková, Karolína ; Sedláček, Ondřej (advisor) ; Poláková, Simona (referee)
Urbanisation process is recently a wide-spread process that causes high-impact environmental transformation. Habitats affected by urbanization tend to change substantially and ongoing changes influence organisms living in this environment. Urban environment modifies many abiotic conditions (e.g. temperature, artificial light and noise) and biotic factors (e.g. food supply, parasite prevalence, predation pressure) in comparison to natural habitats. In this manner, especially urban bird populations have recently gained broad attention by an increasing number of ecologists. Urban avoiders - typically sensitive and specialized bird species often vanish from urbanized landscapes. However, many bird species were able to colonize urban environment and coexist successfully with man. Populations of birds living in such a new type of environment show many characteristics different from populations living in original habitats. The objective of this work is to review current studies about changes of life strategies in urban bird populations such as modifications of acoustic signals, differences in reproductive and food ecology and physiological or behavioural responses.
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The effect of urbanization on life-history strategies in birds
Houšková, Karolína ; Sedláček, Ondřej (advisor) ; Poláková, Simona (referee)
Urbanisation process is recently a wide-spread process that causes high-impact environmental transformation. Habitats affected by urbanization tend to change substantially and ongoing changes influence organisms living in this environment. Urban environment modifies many abiotic conditions (e.g. temperature, artificial light and noise) and biotic factors (e.g. food supply, parasite prevalence, predation pressure) in comparison to natural habitats. In this manner, especially urban bird populations have recently gained broad attention by an increasing number of ecologists. Urban avoiders - typically sensitive and specialized bird species often vanish from urbanized landscapes. However, many bird species were able to colonize urban environment and coexist successfully with man. Populations of birds living in such a new type of environment show many characteristics different from populations living in original habitats. The objective of this work is to review current studies about changes of life strategies in urban bird populations such as modifications of acoustic signals, differences in reproductive and food ecology and physiological or behavioural responses.
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Has .i.Tilia x euchlora./i. a detrimental effect on soil annelids in urban greens?
Schlaghamerský, J. ; Khodabocus, J.B. ; Pižl, Václav
The potential effect of the exotic linden .i.Tilia x euchlora./i., widely planted in urban greens, on soil-dwelling annelids (Lumbricidae, Enchytraeidae) was investigated in two parks in the city of Brno, Czech Republic. Linden trees are the source of honeydew that might affect soil biota and remains an important input of these trees into the soil compartment even if litter is being removed as part of the park management. There have also been discussions about the alleged toxicity of .i.T. x euchlora./i. nectar to pollinators. The native .i.T. platyphyllos./i. was used as a control. Within two days in November 2006 annelids were sampled at three different distances (1 m, 3 m, 6 m) along transects from the trees to well developed lawns. Earthworms were extracted by the electrical-octet method, enchytraeids by wet funnel extraction from soil cores taken down to 12 cm.
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