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Distribution and habitat preference of the Ortolan Bunting in the Czech Republic
Zeman, Vít ; Lučan, Radek (advisor) ; Šťastný, Karel (referee)
The Ortolan Bunting (Emberiza hortulana) is a farmland bird species, whose population size has declined very sharply in recent decades, especia ll y in Western and Central European countries. The aim of our study in 2015 was to record where the last populations of this critically endangered species in the Czech Republic are located and also what habitat the species associated with. We examined nine areas (925 km2 in total). Two main areas of occurrence (surface mines in northern Bohemia and farmland landscape of Silesia) and two small isolated populations in central Bohemia were registered for this species. In contrast, observations in some traditional areas of its occurence (České středohoří in northern Bohemia, Hovorany-Čejkovice region in southe r n Moravia and Javoricko region in Silesia) were negative. Altogether, we counted 75-79 singing males. Our estimation of the size of the Czech population in 2015 is 75-100 singing males, which indicates further population decline compared to the last mapping in 2001-2003. Furthermore, habitat associat io ns were investigated at two spatial scales and we made habitat compar is o n between farmland and post-mining landscape. Our research highlights a high degree of flexibility in habitat selection of Ortolan Bunting and also positive association with high...
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Niche Partitioning in Tropical Birds
Petruf, Miroslav ; Sedláček, Ondřej (advisor) ; Exnerová, Alice (referee)
in English Niche partitioning is a process that allows species to coexist by minimizing competition. Niches get narrow with growing habitat heterogeneity, which is evident in tightly packed tropical communities. Closely related species exhibit a high niche overlap, which intensifies competition for resources in their sympatry. Such birds avoid competitive exclusion by foraging using different methods or in different strata. Character displacement makes sympatric species diverge in foraging niches as well as in morphology, allowing specialized species to access private resources. Tropical birds in seasonal environments tend to occupy different niches in the wet and in the dry season, based on the availability of resources in their preferred habitats. Resource subdivision in sympatric members of an ecological guild usually depends on body-size- determined dominance. Territoriality may depend on the costs and benefits of defending resources, which may change seasonally. Dominance statuses vary within populations of the same species, too, promoting intra-specific niche partitioning. Within-species differences in foraging can also be the result of sexual dimorphism or differences in reproductive roles. Moreover, intra-specific differences in foraging may also explain the partial migration of some...
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Biotopové nároky synantropních ptáků (vrabec domácí, vrabec polní a hrdlička zahradní)
MACHOVÁ, Markéta
Aim of this study was to assess distribution and abundance of common synanthropic species of birds (House sparrow, Tree sparrow, Eurasian collared dove and Blackbird) in area of the city České Budějovice in the Czech Republic in autumn and winter. Habitat preferences of these species were analysed. Study also determined influence of the certain characteristics of urban vegetation on their occupation by both species of sparrows.
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Amphibian habitat preferences in selected localities after mining moldavites.
NĚMEC, Stanislav
This thesis pursues amphibian biotop preferences in locations where moldavites were quarried in the past. Field work took place in two localities near Trhové Sviny. The first one is situated near the village of Slavče where an illegal extraction still occures,.The second locality is found by the village of Dobrkovská Lhotka. This locality was partially recultivated in 2010. The aim of this work was to establish which factors do influence different amphibian species in the both studied locations. There were found five various species of amphibians near the village of Slavče: the Common frog (Rana temporaria), the Edible frog (Pelophylax kl. esculentus), the European fire-bellied toad (Bombina bombina), the European tree frog (Hyla arborea) and the Common toad (Bufo bufo). The results were statistically evaluated. Based on them it was established that the Common frog prefers the herb layer, the European Fire-bellied toad prefers semi shaded medium sized pools that do not dry up. The European tree frog and the Edible frog prefer large areas of pools and ponds. More over the edible frog demands ponds that are partially overgrown. The Common toad was represented only with one single individual. Therefore a statistical analasys could not be executed. The whole locality is negatively influenced by local inhabitants who gather here manure and organic waste from their gardens. On locality located near to Dobrkovská Lhotka was transformed from a mining landscape to a pond and three pools. All amphibian species that lived in the locality before reclamation were still present here. Occurrence of Common spadefoot (Pelobates fuscus) was confirmed by the unique finding of a tadpole. Statistical evaluation was not conducted due to the small number and variability of monitored sites.
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