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Mimicry in hoverflies
Daňková, Klára ; Hadrava, Jiří (advisor) ; Raška, Jan (referee)
Batesian mimicry, the imitation of harmful species manifested by harmless ones, could bring a lower risk of predation to the mimetic species. Therefore, it occurs in many different taxa. Hoverflies (Diptera: Syrphidae) could stand for one of the most various mimics. This worldwide-distributed family is known for taking shape of many Aculeata species using plenty of different adaptation connected with colouration, morphology and even behaviour. The aim of this work is to review the diversity of mimicry in Syrphidae, highlight the main selection pressures and to put forward a potential field of future research. Hoverflies are being studied for the last two hundred years. However, just several study approaches are dominating the field. In order to open a new chapter of their research, I bring a wider synthesis of knowledge related to the ecological and evolutionary context of this phenomenon.
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Evolution and function of polymorphism in warningly coloured prey
Fárová, Monika ; Exnerová, Alice (advisor) ; Šulc, Michal (referee)
Polymorphism can be expected in warningly colored prey if the prey is protected from predation by nothing else but its coloration. On the contrary, in defended prey, polymorphism was only until recently considered a controversial phenomenon due to its longer and costly avoidance learning. Individual moprhs can vary in different components of warning coloration: color, pattern, melanization degree, and internal and external contrast of colour patterns. This makes it difficult for predators to learn and remember warning signals of defended prey and avoid it in the future. Predator selection pressures and mechanisms leading to polymorphism differ between defended and undefended prey. For undefended prey, it is a negative frequency-depended selection that supports rare morphs or the multiple models hypothesis for one mimetic species. For defended prey, the polymorphism can occur temporarily (i. e., be unstable) and it also can be allowed by spatial heterogeneity of morphs or, as for undefended prey, one species can mimic multiple models. Quasi-Batesian mimesis could also contribute to the existence of the polymorphism, due to mechanisms similar to those in unprotected prey. Apart from selection by predators, there are other factors, that contribute to the existence of polymorhism in prey warning...
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Evolution and function of polymorphism in warningly coloured prey
Fárová, Monika ; Exnerová, Alice (advisor) ; Šulc, Michal (referee)
Polymorphism can be expected in warningly colored prey if the prey is protected from predation by nothing else but its coloration. On the contrary, in defended prey, polymorphism was only until recently considered a controversial phenomenon due to its longer and costly avoidance learning. Individual moprhs can vary in different components of warning coloration: color, pattern, melanization degree, and internal and external contrast of colour patterns. This makes it difficult for predators to learn and remember warning signals of defended prey and avoid it in the future. Predator selection pressures and mechanisms leading to polymorphism differ between defended and undefended prey. For undefended prey, it is a negative frequency-depended selection that supports rare morphs or the multiple models hypothesis for one mimetic species. For defended prey, the polymorphism can occur temporarily (i. e., be unstable) and it also can be allowed by spatial heterogeneity of morphs or, as for undefended prey, one species can mimic multiple models. Quasi-Batesian mimesis could also contribute to the existence of the polymorphism, due to mechanisms similar to those in unprotected prey. Apart from selection by predators, there are other factors, that contribute to the existence of polymorhism in prey warning...
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Mimicry in hoverflies
Daňková, Klára ; Hadrava, Jiří (advisor) ; Raška, Jan (referee)
Batesian mimicry, the imitation of harmful species manifested by harmless ones, could bring a lower risk of predation to the mimetic species. Therefore, it occurs in many different taxa. Hoverflies (Diptera: Syrphidae) could stand for one of the most various mimics. This worldwide-distributed family is known for taking shape of many Aculeata species using plenty of different adaptation connected with colouration, morphology and even behaviour. The aim of this work is to review the diversity of mimicry in Syrphidae, highlight the main selection pressures and to put forward a potential field of future research. Hoverflies are being studied for the last two hundred years. However, just several study approaches are dominating the field. In order to open a new chapter of their research, I bring a wider synthesis of knowledge related to the ecological and evolutionary context of this phenomenon.
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Experimental studies of Müllerian mimetic complexes
Jůnová, Lenka ; Exnerová, Alice (advisor) ; Hotová Svádová, Kateřina (referee)
Mimicry is one of strategies which provides protection for the prey from predator attack. There are several kinds of mimetic relationships, one of them is Müllerian mimicry, i.e. mutualistic relationship between two unpalatable prey species. If there are more animal species in this relationship, it is called Müllerian mimetic complex. Relationships in mimetic complexes are affected by many factors like defence level and aposematic signals resemblance of particular species, their different frequencies, alternative prey, prey community structure or predator species and their experience level. These factors determine whether the relationship of the species involved is mutualistic or parasitic. They also affect predators behaviour and their learning rate, memory and generalisation between mimetic species. Powered by TCPDF (www.tcpdf.org)
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