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Ptačí budky a další způsoby zvyšování hnízdních možností ptáků

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... V minulosti bylo navrženo několik možných cest k zlepšení současného stavu a k omezení rizik, která s masivním vypouštěním uměle odchovaných jedinců souvisí. Někteří autoři (Zasadil 2001, Zbořil et al. 2007 ) navrhují jako alternativu k umělému chovu a vypouštění zvyšování hnízdních příležitostí stavbou hnízdních budek. Přestože hnízdní budky mohou do určité míry v případě kachny divoké nabídnout hnízdní možnosti, není jasné, do jaké míry je velikost její populace přímo limitovaná nedostatkem hnízdních příležitostí. ...
... Přestože hnízdní budky mohou do určité míry v případě kachny divoké nabídnout hnízdní možnosti, není jasné, do jaké míry je velikost její populace přímo limitovaná nedostatkem hnízdních příležitostí. Pokud by měla být tato cesta alespoň částečně efektivní, měla by jít ruku v ruce se zlepšováním kvality biotopů kachny divoké a dalších vodních ptáků, za jejichž ztrátou a degradací stojí meliorace, lidská zástavba a intenzifikace chovu ryb (Musil et al. 2001, Zasadil 2001, Musil & Cepák 2004, Baldassarre & Bolen 2006, Broyer & Curtet 2012). Navíc, navýšení početnosti hnízdní populace v rámci České republiky z odhadovaných 25 000 až 45 000 párů (Birdlife International 2004, Šťastný et al. 2006) tímto způsobem na úroveň, kdy by bylo možné, stejně jako v uplynulém desetiletí, udržitelně lovit ročně cca 250 až 300 tisíc kusů kachny divoké (ÚHÚL 2015), se jeví jako nerealistické. ...
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A decrease in the numbers of the Mallard (Anas platyrhynchos) has led to game-farming and the release of captive-bred Mallards for hunting purposes in many states, including the Czech Republic, frequently on a large scale. In this way, more than three million Mallards are released globally every year. Captive animals are affected by different selection pressures and evolutionary processes than those living in the wild, that may lead to genetic and phenotypic divergence between these populations. Although greater attention of the scientific research to the possible risk of hybridization and introgression of released individuals with wild populations has been mainly focused on supplementations of endangered species, there is a growing interest in the issue of restocking recreationally hunted species. Studies show that captive rearing has led to a loss of genetic diversity, as well as to morphological, physiological and behavioural differentiation in the farmed Mallard populations compared with wild populations. The divergence between these populations, despite the development in standardized conditions, suggests that these differences are genetically-determined. The observed phenotypic divergence is thus not only a result of the phenotypic plasticity of these traits. Therefore, restocking of Mallards poses a threat to the genetic identity and variability of wild populations and may potentially lead to phenotypic changes. This paper reviews the scientific literature dealing with this issue and discusses possible measures and the importance of monitoring of Mallard supplementations.
... Na druhé straně spektra je zejména amatérskými ornitology běžně prováděn monitoring hnízdní obsazenosti budek jednotlivými druhy ptáků (a dalších organismů; Veľký 2006, Svoboda & Švorc 2011), který je např. společně s pravidelným čištěním přirozenou součástí zažitého " protokolu " péče o budky (Obhlídal 1979, Zasadil 2001, ČSOP 2014). Budky jsou ovšem ptáky využívány i v mimohnízdním období, a to zejména k zimnímu nocování – i v tomto období je proto zajímavé monitorovat obsazenost budek. ...
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Nest boxes provide an opportunity to study bird life not only during the breeding season, but even in winter, when the birds use them as roost sites. Wintertime occupancy is usually detected by direct night checks of nest boxes, which are physically demanding and may disturb the roosting birds. Here we present an alternative way how to study the wintertime nest box occupancy based on the estimate of " droppings cover " from the photographs taken in late winter. We confronted the droppings cover with the occupancy revealed by direct night checks. The data were collected in the Království u Grygova floodplain forest, Olomouc District, Czech Republic, in 2007–2010. Nest box occupancy was clearly predictable from the droppings cover. We discuss the applicability of the model to predict nest box occupancy from the dr oppings cover, as well as factors that may affect the estimation of droppings cover from the photographs, such as the nest box size, length of the studied winter period, or the species of roosting birds.
... Na druhé straně spektra je zejména amatérskými ornitology běžně prováděn monitoring hnízdní obsazenosti budek jednotlivými druhy ptáků (a dalších organismů; Veľký 2006, Svoboda & Švorc 2011), který je např. společně s pravidelným čištěním přirozenou součástí zažitého " protokolu " péče o budky (Obhlídal 1979, Zasadil 2001, ČSOP 2014). Budky jsou ovšem ptáky využívány i v mimohnízdním období, a to zejména k zimnímu nocování – i v tomto období je proto zajímavé monitorovat obsazenost budek. ...
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Nest boxes provide an opportunity to study bird life not only during the breeding season, but even in winter, when the birds use them as roost sites. Wintertime occupancy is usually detected by direct night checks of nest boxes, which are physically demanding and may disturb the roosting birds. Here we present an alternative way how to study the wintertime nest box occupancy based on the estimate of “droppings cover” from the photographs taken in late winter. We confronted the droppings cover with the occupancy revealed by direct night checks. The data were collected in the Království u Grygova floodplain forest, Olomouc District, Czech Republic, in 2007–2010. Nest box occupancy was clearly predictable from the droppings cover. We discuss the applicability of the model to predict nest box occupancy from the dr oppings cover, as well as factors that may affect the estimation of droppings cover from the photographs, such as the nest box size, length of the studied winter period, or the species of roosting birds.
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