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Effect of climatic and environmental variables on changes in numbers and migratory behaviour of wintering and migrating waterbirds.
Adam, Matyáš ; Musil, Petr (advisor) ; Bejček, Vladimír (referee)
Waterbirds with their specific habitat and food requirements varying during their annual cycle (Riffell et al. 2003; Taft and Haig 2006) are able to indicate the wetland diversity and quality due to their rapid responses on changes in environment (Delany 1999; Fernández et al. 2005; Amat and Green 2010). Remarkable land cover changes and climate warming led to significant shifts in distribution and abundance of many waterbird species across Europe in recent decades (Delany et al. 2006; Fox et al. 2010; Lehikoinen et al. 2013; Pavón-Jordán et al. 2015). To understand the dynamic of migratory birds in space and time and to assess effects of global conditions as well as local conditions of individual sites during their annual cycle there is need of international monitoring and research. Since the start of International Waterbird Census in 1967 both increasing and decreasing trends have been recorded in nearly fifty percent of waterbird species in Western Palearctic (Delany et al. 2006, Wetlands International 2016) and they consequently have affected trends in particular countries, including the Czech Republic. Wetland sites in the Czech Republic are generally situated on the edge of wintering range of most waterbird species (Gilissen et al. 2002), however the prevailing increase in abundance of waterbird species has been recorded here in recent decades (Musil et al. 2011). Though, the considerable growth of winter temperatures has not been noticed in the Czech Republic (Klein Tank et al. 2002; Musilová et al. 2009; Dušek et al. 2013), and the accessibility of the wetland sites, due to their freezing, varies year to year. Hence, we can assume that waterbirds have likely began using the alternative habitats with available food resources, i.e. cold-weather refuges, probably regardless of their conservation status (Musilová et al. 2015). Special protection areas were implemented to Czech legislation in 2004 to protect migratory birds (Birds Directive 2009/147/EC). So far there has not been tested the effectivity and impact of legislative protection on wintering waterbird species. Moreover, some previous studies indicated that SPA network do not match the species distribution pattern (López-López et al. 2007; Briggs et al. 2012; Albuquerque et al. 2013), so this issue urgently calls for scientific research.
The second part of the thesis focused on Greylag Geese, whose abundance has rapidly grown across the Europe in recent decades (Madsen et al. 1999; Fox et al. 2010), and that have become ideal model species to observe their responses to habitats and climate changes as well as their reactions to human disturbance (Fox and Madsen 1997; Ramo et al. 2015). This requires appropriate knowledge of geese distribution, abundance and their behaviour. Since 1930s, when the geese started to be ringed in the Czech Republic, the ringing intensity have markedly varied and have been reflected in numbers of recoveries. In last ten years the intensity have increased (Podhrazský 2010). However, complex of the historical data until 2002 (Cepák et al. 2008) and recent data have not been analysed so far. In the light of recent shifts in wintering ranges and migration phenology of many goose populations these analyses require increased attention. Furthermore, the satellite monitoring of geese is coming to detect more detailed information about behaviour of individuals.
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