24 research outputs found

    Význam predace pro hnízdní ekologii a ochranu bahňáků

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    Predace je nejčastější příčinou reprodukčního neúspěchu a silně ovlivňuje hnízdní produktivitu a celkovou populační dynamiku ptáků. Zároveň významně ovlivňuje evoluci jejich životních strategií. Výzkum faktorů ovlivňujících míru predace a kvantifikace následků predace jsou velmi významné z pohledu evoluční ekologie i druhové ochrany, zejména v současně se rychle měnícím světě. V této dizertační práci řeším vztahy mezi: mírou predace hnízd nebo kuřat, environmentálními faktory a životními strategiemi, vše společně s následky pro populační dynamiku a ochranu přírody. Skupina bahňáků představuje vhodný modelový systém ze třech důvodů: 1) bahňáci jsou rozšířeni celosvětově; 2) hnízdí převážně na zemi a jejich hnízda mají mezidruhově velmi podobný vzhled pro potenciální predátory; 3) hnízdní predace u bahňáků je dostatečně prostudována napříč celým světem. V rámci dvou částí této dizertační práce, Predace v zemědělské krajině a Mezidruhové interakce a anti-predační strategie, podporujeme termoregulační hypotézu velikosti hnízdní výstelky, nikoliv však anti-predační adaptaci (Kapitola 2). Dále z predační perspektivy diskutujeme dvojitou výhodu kuřat vylíhnutých z větších vajec na začátku hnízdní sezóny s větším množstvím dostupné potravy (Kapitola 3). Představujme vhodné řešení, jak efektivně značit...Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold...Katedra ekologieDepartment of EcologyPřírodovědecká fakultaFaculty of Scienc

    Význam predace pro hnízdní ekologii a ochranu bahňáků

    Get PDF
    Predace je nejčastější příčinou reprodukčního neúspěchu a silně ovlivňuje hnízdní produktivitu a celkovou populační dynamiku ptáků. Zároveň významně ovlivňuje evoluci jejich životních strategií. Výzkum faktorů ovlivňujících míru predace a kvantifikace následků predace jsou velmi významné z pohledu evoluční ekologie i druhové ochrany, zejména v současně se rychle měnícím světě. V této dizertační práci řeším vztahy mezi: mírou predace hnízd nebo kuřat, environmentálními faktory a životními strategiemi, vše společně s následky pro populační dynamiku a ochranu přírody. Skupina bahňáků představuje vhodný modelový systém ze třech důvodů: 1) bahňáci jsou rozšířeni celosvětově; 2) hnízdí převážně na zemi a jejich hnízda mají mezidruhově velmi podobný vzhled pro potenciální predátory; 3) hnízdní predace u bahňáků je dostatečně prostudována napříč celým světem. V rámci dvou částí této dizertační práce, Predace v zemědělské krajině a Mezidruhové interakce a anti-predační strategie, podporujeme termoregulační hypotézu velikosti hnízdní výstelky, nikoliv však anti-predační adaptaci (Kapitola 2). Dále z predační perspektivy diskutujeme dvojitou výhodu kuřat vylíhnutých z větších vajec na začátku hnízdní sezóny s větším množstvím dostupné potravy (Kapitola 3). Představujme vhodné řešení, jak efektivně značit...Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold...Katedra ekologieDepartment of EcologyFaculty of SciencePřírodovědecká fakult

    Global pattern of nest predation is disrupted by climate change in shorebirds

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    Ongoing climate change is thought to disrupt trophic relationships, with consequences for complex interspecific interactions, yet the effects of climate change on species interactions are poorly understood, and such effects have not been documented at a global scale. Using a single database of 38,191 nests from 237 populations, we found that shorebirds have experienced a worldwide increase in nest predation over the past 70 years. Historically, there existed a latitudinal gradient in nest predation, with the highest rates in the tropics; however, this pattern has been recently reversed in the Northern Hemisphere, most notably in the Arctic. This increased nest predation is consistent with climate-induced shifts in predator-prey relationships

    Significance of predation for breeding ecology and conservation in shorebirds

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    Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold..

    Significance of predation for breeding ecology and conservation in shorebirds

    No full text
    Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold..

    Significance of predation for breeding ecology and conservation in shorebirds

    No full text
    Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold..

    Significance of predation for breeding ecology and conservation in shorebirds

    No full text
    Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold..

    The Northern Lapwing ( Vanellus vanellus) -- a model species for research of precocial problems in Shorebirds ( Charadrii)

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    Precociality has large energy demands on a freshly hatched chick which must start to feed itself and face environmental factors more than altricial nestlings. The Northern Lapwing (Vanellus vanellus) is a suitable model species for presenting the precocial problems of shorebirds (Charadrii), a typical precocial group of birds. A better understanding of the lapwing chick's problems in different habitats will deepen our knowledge about ecological constraints and adaptations of precocial shorebirds and, at the same time can be very helpful for determining the rules of effective conservation of endangered species. The chick size, growth, condition and survival are influenced by egg volume but also by the quality of the parents during the 35 day period that the chick needs to achieve fledging. A Lapwing chick's mortality is highest during the first 10 days of its life due to all of the further mentioned factors, which are even stronger in the critical and delicate period of the chick's life after hatching. Lapwing chicks forage non-selectively on the most abundant and available types of prey found on the soil surface, in soft mud or shallow water. Their diet consists of various types of invertebrates, particularly earthworms, beetles and other groups of insects. The proportion of particular food..

    Significance of predation for breeding ecology and conservation in shorebirds

    No full text
    Predation is the most common cause of reproduction failure and it strongly influences breeding performance in birds, impacting the whole species population dynamics as well as it represents a major force in the evolution of avian life-history strategies. Investigating the factors driving predation rates, or quantifying predation consequences, is highly relevant for evolutionary ecology as well as for species conservation, especially in a rapidly changing world. In this dissertation, I investigate links between nest and chick predation, environmental factors, life-history and anti-predatory strategies, together with consequences for population dynamics and conservation. I use shorebirds as a uniquely suitable model system for three reasons: i) they are globally distributed; ii) have predominant ground nesting strategy and high interspecific similarity in nest appearance to potential predators; iii) are sufficiently well- studied in terms of nest predation all over the world. In the two first sections of this dissertation, Predation in the agricultural landscape and Interspecific interactions and anti-predatory strategies, Chapter 2 supports the thermoregulatory hypothesis of nest lining size rather than anti-predatory adaptation. Chapter 3 discusses, from the perspective of predation, the twofold..
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