National Repository of Grey Literature 31 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Reproductive behaviour of males of Golden-ringed Dragonfly (Cordulegaster boltonii)
Dubcová, Dominika ; Černý, Martin (advisor) ; Dolný, Aleš (referee)
Communication among animals often relies on visible signals and the ability to compatibly perceive them. Correct signal perception is especially important for animals with male sexual selection. In my master's thesis, I am addressing the issue of how does a male golden-ringed dragonfly (Cordulegaster boltonii) recognize a female of the same kind and therefore, what is the main trigger of copulation behavior. Dragonflies display a wide variety of colors and possess very big eyes. These characteristics already suggest that they are very liable on color vision (Futahashi, 2015). Their sight is perfectly developed within the insect class and plays the most important role in the imagines in comparison to other senses. The ability to orient themselves using sight is not just important for orientation in space, nonetheless it is important for reproduction. Since golden-ringed dragonflies do not demonstrate visible color dimorphism, previous as well as my research suggests that the key role for female reconnaissance is primarily their typical movement above water surface during oviposition. In my research, I presented variable types of lure - females to male golden-ringed dragonflies and I observed what is the foremost trigger of reproduction behavior in the males. Besides the above mentioned female...
Entomological survey of the locality Wetland meadows near Jetřichov
Mocek, Bohuslav ; Mikát, Miroslav
Zjištěny druhy zachovalých mokřadních a rašelinných lučním společenstev, např. modrásek Maculinea nausithous, perleťovec kopřivový Brenthis ino, můry Celaena leucostigma, Mythimna impura a Xestia sexstrigata. Lesní a arborikolní druhy např. píďalky Deileptenia ribeata a Puengeleria capreolaria, a lokální druhy brouků Rabocerus gabrieli a lesknáček Epuraea distincta. Xerofilní druhy, jako např. zaviječ Pempeliella ornatella, můra Calophasia lunula, okáč zední (Pararge megera) pronikají od suchých úhorů od železnice v s. části lokality.
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Spatial orientation in Odonata
Hupková, Lenka ; Černý, Martin (advisor) ; Sacherová, Veronika (referee)
The aim of this review is to evaluate and sum up an existing knowledge about spatial orientation of dragonflies, particularly at small and medium spatial scales. I deal mostly with orientation by horizontally polarized light, which belongs among the most explored field of orientation of Odonata; beside that I explore an orientation of dragonflies during the habitat selection and within their home ranges / territories. Regarding the latter, I pay an attention namely to the function of spatial landmarks, which has not been yet fully explored and offers a lot of opportunities for further research (like many other orientation topics of Odonata). I also briefly discuss an orientation of dragonflies during migrations. Besides the visual orientation I mention the orientation by olfactory sense, tough Odonata was concerned anosmic for a long time. Key words: spatial orientation, visual orientation, dragonflies, Odonata, landmarks
Local dispersal of Golden-ringed dragonfly Cordulegaster boltonii
Hančíková, Barbora ; Černý, Martin (advisor) ; Dolný, Aleš (referee)
We carried out a pilot study of local dispersion and patterns of movement of Golden- ringed dragonfly Cordulegaster boltonii (Odonata: Cordulegasteridae). Cordulegasteridae is a family with many primitive traits present and rather restricted geographical distribution ranges (at least among European species). Their migration seems to be limited despite the body size that predetermines them to high mobility over large spatial scale. Linear habitat (upper parts of narrow forest streams) specialisation along with behavioural ecology (peculiar premating habit of scanning streams for females) is a unique life history, which bring lot of questions. We collected mark-release-recapture data during two adult flight seasons in year 2010 and 2011. We were simultaneously capturing patrolling males along three separate streams (Dračice, Koštěnický and Struha) in total length of 9.9 km in, located in the Natural park Česká Kanada, in the Southern Czech Republic. We captured and marked 440 individuals and recorded 113 recapture events (26 % recapture rate) in year 2010 and 355 individuals were marked, 171 recapture events made (48 % recapture rate) in 2011. Our data suggested high level of stream fidelity (only 10 inter stream dispersal events, 2.8 % dispersal rate). What was as well reflected in a closeness of...
Factors affecting dragonfly species composition in newly created pools and assessment of invertebrate predation on pools zooplankton
Dobiáš, Jakub ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
To identify and quantify the influence of physico-chemical, biotic and geographic factors on the population of dragonflies (Odonata) is an essential tool for research of their ecology. The aim of this study was to 1) assess how these factors influence species richness, diversity and spatial distribution of dragonflies in 42 newly constructed or renewed pools located in the Kokořínsko Protected Landscape Area, which is characterized by two valleys of Liběchovka and Pšovka creeks, low human impact, and a great diversity of small water bodies and 2) use laboratory experiments in order to estimate the relationship between large predatory invertebrates of these pools (Aeshna cyanea, Coenagrion puella, Chaoborus crystallinus and Notonecta glauca) and their common prey (Daphnia curvirostris) in an artificial environment with or without aquatic macrophytes. The pools were monitored and sampled between years 2005 and 2006. In total, 23 dragonflies species were found inhabiting these lentic habitats, comprising 11 species belonging to the suborder Zygoptera and 12 species belonging to the suborder Anisoptera, including a rare species Sympetrum depressiusculum (larvae). Most variability in the dragonfly species richness was explained by the size of the water surface area, followed by the location of the pools (inside...
Population and spatial dynamics of Winter Damselflies (Odonata: Lestidae)
Jablonická, Zuzana ; Harabiš, Filip (advisor) ; Kadlec, Tomáš (referee)
The main subject of this study was Sympecma fusca, damselfly species representing life history with many specific adaptations. One of the unique adaptation is overwintering in adult life stage outside the water habitat. The aim of this thesis is to analyze distribution of this species in terrestrial environment, as well as changes in abundance during the season. Sympecma fusca is common winter damselfly in Czech Republic, occurring on variety of still freshwater habitats with rich vegetation. During overwintering this species actively searching for micro-habitats situated in terrestrial environment, providing shelter and reducing the mortality risks. Capture-Mark-Recapture Method was applied to describe the population dynamics of this species. The experimental part was divided into two periods: pre-reproductive (autumn) and reproductive (spring). Subsequent analysis provide estimation of total number of individuals in population during season. The results showed significant habitat preference of ecotones between forest and meadow over forest and open habitats. However, this preference was confirmed only during pre-reproductive period, the time when imagoes were looking for suitable shelter for the overwintering. These findings can be used to in understand the habitat preference of this species, but also general factors that can affect its abundance.
Conservation value of post-mining headwaters: drainage channels at a lignite spoil heap harbour threatened stream dragonflies
TICHÁNEK, Filip
In the work, we studied the biodiversity of dragonflies and damselflies (Odonata) at 53 sections (30 m) of an extraordinarily dense system of drainage ditches at a large lignite spoil heap in the Czech Republic. Using generalized linear models and canonical correspondence analyses we identified crucial factors affecting dragonfly communities and suggested implications for restoration ecology practise.
Biotic and abiotic factors affecting territorial and reproductive behaviour of dragonflies (Odonata)
KYBICOVÁ, Tereza
Habitat selection, territorial behaviour and reproductive behaviour of dragonflies (Odonata) are discussed and biotic and abiotic factors affecting their territorial and reproductive behaviour are reviewed. The most important biotic factors are predation risk affecting larval survival and the presence of aquatic vegetation, which provides spatial structure. The review is complemented by a field study of territorial and reproductive behavior of dragonflies at an experimental site, at which the quality of individual pools was manipulated by a combination of the presence or absence of artificial vegetation and the presence or absence of an introduced top predator (late-instar larvae of Anax and Aeshna).
How predation risk affects the growth and development of dragonfly larvae?
PEROUTKA, Miroslav
Predation and prey responses to predators in aquatic environment are reviewed with emphasis on non-lethal effect of predators on prey life history, antipredator behavior and related mechanisms. The review focuses on dragonfly larvae and other groups of prey with complex life histories, mainly anurans. The review is complemented by laboratory experiments examining the effects of varied food availability and predation risk on a selected species of dragonfly, Sympetrum vulgatum.

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