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Influence of the intensity of begging on the rate of predation in the common sandpiper and common cuckoo
ČAPEK, Jan
In this research, I examined whether the louder calls of the common cuckoo (Cuculus canorus), a nest parasite, would increase the rate of predation on the nest of the red-backed shrike (Lanius collurio), whose nestlings call at a lower volume. The experiment was conducted during both the nesting season of the red-backed shrike, primarily in June, and in the autumn of 2023. During the spring trials, nests were situated within bushes, whereas in the autumn trials, they were positioned on the ground. Each experiment involved three nests, each subjected to a distinct audio recording: one featuring the vocalizations of a young common cuckoo, another with those of nestlings of the red-backed shrike, and a third serving as a silent control. Predation rates were assessed across these nests to determine whether certain recordings elicited higher predation rates compared to others.
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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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Gastropods, trees, pH, subsoil and epiphytic lichens
Pelant, Filip ; Svoboda, David (advisor) ; Peksa, Ondřej (referee)
Epiphytic lichens are under considerable grazing pressure due to invertebrate lichenivores, mostly gastropods. Preferences of tree-climbing gastropods affect vertical distribution of lichens, their habitat preferences and whole area of distribution. Higher grazing pressure is expected on sites with basic subsoil and sufficient sources of calcium, where the abundance of gastropods is higher. Most of researches about the topic of grazing pressure were therefore conducted on such sites, although this hypothesis has never been formally tested. Epiphytic communities are also affected by pH and other properties specific to its photophyte. Nevertheless, it is not known, if the same applies for grazing gastropods and how is the grazing pressure affected by tree species. I have addressed these questions in my thesis. I set an 80-days-long field transplantation experiment in the mixed forest of Moravský kras (South Moravia, Czech Republic). Glass fiber meshes with lichen thalli were placed on sixty trunks of three tree species (Carpinus betulus - hornbeam, Abies alba - fir, Fagus sylvatica - common beech) on both calcareous (limestone) and acidic (granodiorite) sites. Abundance and diversity of gastropods were measured. Determined grazing pressure was higher than pressure detected by other authors and was...
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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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Is there any seasonal differences in terrestrial habitat use in dragonflies?
Hronková, Jana ; Harabiš, Filip (advisor) ; Aleš, Aleš (referee)
Dragonflies (Odonata) passing through several life stages during their life cycle. During metamorphosis between stages, they did not change only morphology, but also habitat preferences. Although they are associated to aquatic environment during larval stage, adults are much more mobile and can utilize the surrounding terrestrial habitats. Adult dragonflies are also involved in to terrestrial food chains. However the relationship, between the quality of terrestrial habitats and the diversity of dragonflies as well as seasonal changes in utilization of these habitats are still not known. This thesis aiming to analyze the influence of seasonality and distance from aquatic habitat on the abundance of dragonflies. Moreover, the differences in fish farming intensity were considered in the analyses. Fieldwork took place during 2015 from May to September. Data from 29 localities of Czech Republic were included. It is not surprising that I found significant influence of seasonality, on the abundance of all species, as well as a negative relationship between dragonfly abundance and distance from water reservoir. Interestingly, it was found, that dragonfly utilization of terrestrial areas around the extensively managed habitats was significantly higher than in habitats around intensively managed ponds. These findings demonstrate the importance of terrestrial habitats for dragonflies, especially those occurring around extensively managed water habitats.
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Evaluation of Great Cormorant predation activities (Phalacrocorax carbo sinensis) during the spring and autumn migration to ponds on School´s Piscicapture in Protivín between the years 2009-2011
KOTLÍN, Vít
Evaluation of Great Cormorant predation activities (Phalacrocorax carbo sinensis) during the spring and autumn migration to ponds on School´s Piscicapture in Protivín between the years 2009 - 2011 and compensation for damages in accordance to the law No. 115/2000 Coll. I compared the results of self-monitoring with the majority known information from many sources in the literature and confirmed the fact that predation pressure are frequently exposed those ponds which are providing food supply in the form of dense fish stock with an acceptable piece weighing 0.03 to 0.5 kg independently on the size of the pond. Confirmed facts are exposed to the conclusion on today's constantly evolving legislation allowing compensation for damages caused by Great cormorant - Act No. 115/2000 Coll. versus regulations No. 393/2012 Coll. and No. 432/2005 Coll.
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