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Habitat selection by dragonflies - effect of littoral and riparian vegetation
Bonková, Anita ; Černý, Martin (advisor) ; Waldhauser, Martin (referee)
Dragonflies form one of the important pillars of most aquatic ecosystems and play an important role in maintaining their balance. The main goal of this bachelor's thesis is to summarize current knowledge about the habitat preferences of members of the order Odonata, with a focus on the effect of littoral and riparian vegetation, which are critical components of aquatic biotopes and significantly influence the distribution, abundance and reproductive success of dragonflies. In my work, I focus on all developmental stages, from larvae to adults. These findings are important for the maintenance and revitalization of freshwater ecosystems, in which it is necessary to pay attention to the composition of littoral and riparian vegetation to support the diverse needs of this unique insect order. Key words: habitat preference, dragonflies, Odonata, riparian vegetation, littoral vegetation
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Dragonflies (Odonata) of selected localities around Benešov
ŘÍHOVÁ, Radka
This bachelor thesis aimed to map the presence of dragonflies (Odonata) in selected locations around the municipalities of Heřmaničky, Velké Heřmanice, and Mrákotice in Benešovsko. This Bachelor thesis is based on pre-conducted field research (dragonfly capture and observation). Another aim of this bachelor thesis was to investigate the natural conditions at eight pre-selected locations in Benešovsko, compare the sites with each other based on environmental characteristics, and find out the presence of dragonfly communities. It has made the suggestion even about didactic use in primary school teaching.
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Dragonflies (Odonata) of selected localities around Borovany, South Bohemia
VOTRUBOVÁ, Daniela
This bachelor thesis focuses on research of the occurrence of Odonata (dragonflies) in the surrounding area Borovany. The research was motivated by a lack of information on the occurrence of Odonata species in this area, which is part of mapping square 7153b. The detection of Odonata communities was carried out through field research. Larvae and imagos were collected at nine pre-selected sites. Larvae and imagos were collected from June to September in 2021, and in the winter months, individual samples were determined in a laboratory. Laboratory equipment and determination keys according to known literature were used to determine individual species of larvae and imagos. The Canoco program (DCA, CCA) and other summary statistical analysis were used to present the results. This work demonstrated the surprising occurrence of Aeshna affinis, Lestes dryas, Sympecma fusca, Coenagrion pulchellum, Coenagrion hastulatum and Gomphus vulgatissimus.
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Predation risk and habitat complexity modify intermediate predator feeding rates and energetic efficiencies in a tri-trophic system
KOLÁŘ, Vojtěch
Many species show behavioural and physiological responses to predation risk, with important implications for their individual growth and development, but these responses may be context dependent. The goal of this study was to measure feeding and metabolic rates of intermediate invertebrate predators under different levels of predation risk and abiotic conditions to understand how they might affect their energetic efficiency, i.e. the ability to utilize available resources for individual growth. We ran laboratory experiments with larvae of three odonate species representing intermediate predators exposed to three levels of predation risk (none, visual cues, and visual and chemical cues) and two levels of habitat complexity (present vs. absent artificial submerged vegetation). We show that the response of intermediate predators to predation risk and its consequences for energetic efficiency are species specific and likely determined by their foraging and defense traits and their habitat domains.
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Dragonflies (Odonata) of selected localities around České Budějovice, South Bohemia
SVYSTUNOVA, Valérie
SVYSTUNOVA, Valérie. Dragonflies (Odonata) of selected localities around České Budějovice, South Bohemia. Bachelor thesis. Faculty of education, University od South Bohemia in České Budějovice. Department od Biology, 42 pages. The bachelor's thesis deals with field research of selected localities around České Budějovice. This is a survey of dragonfly communities in six localities. The aim of the work is to obtain basic faunistic information about the order Odonata and about the natural conditions of the studied areas, to obtain an orientation overview of the character of odonatofauna in selected localities and their mutual comparison, but also with published results of other authors and a proposal for the possible didactic use of the rules in primary school teaching.
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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
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Variation in dragonfly wing venation with application of geometric morphometrics (Insecta: Odonata)
Přibylová, Petra ; Prokop, Jakub (advisor) ; Růžička, Jan (referee)
The pattern of wing venation in dragonflies (Odonata) bears a set of characters commonly used in systematics. The aim of this thesis is to identify the wing venation variability of dragonflies by various methods of geometric morphometric. The wing venation variability was examined on the level of suborder, family, species and also in respect to dimorphism through the principal component analysis (PCA), redundancy analysis (RDA) and centroid size. Data set consisting of images of 46 dragonfly species, belonging to 43 genera and 24 families was obtained from institutional entomological collections. The research carried out that Zygoptera have a large variety of wing contours. The wing venation variability of Epiprocta is shown primarily in the costa and node area. Between sexes there is no noticeable difference in shape or structure of the wing. The ratio between wing length and width and the pterostigma shape is dependent on dragonfly body size. Key words: Odonatoptera, Odonata, Epiprocta, Zygoptera, wing venation, variability, geometric morphometrics
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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...
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Odonata in the urban landscape
Fiala, Bohumil ; Černý, Martin (advisor) ; Harabiš, Filip (referee)
Urbanization is currently one of the main causes of landscape destruction, endangerment of species and homogenization of natural communities. Dragonflies are an important part of freshwater ecosystems. Due to their amphibious life cycle, they are influenced by environmental factors both in a water and on a dry land. Despite the negative impact of urbanization on the environment, the urban landscape has the potential to host a great diversity of organisms, including dragonflies and damselflies. The best way to support local diversity of Odonata is by appropriate management of freshwater habitats, including promoting diversity of aquatic, litoral and riparian vegetation, preserving the original bottom and banks of both lotic and lentic waters and improving water quality in cities. The connectivity of individual localities in the landscape and the reduction of ecological traps are also important ways to ensure the stability of urban populations. Small artificial water reservoirs and well-preserved secondary habitats have the highest conservation potential in most cities. Dragonflies can also play the role of umbrella species for the protection of freshwater communities (not only) in urban areas.
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Golden-ringed Dragonfly (Cordulegaster boltonii): Effect of individual male characteristics on their epigamic behavior
Rohlíková, Barbora ; Černý, Martin (advisor) ; Holuša, Otakar (referee)
My study researches the individual male characteristics of Cordulegaster boltonii in relation to their epigamic behavior. The first part of this study analyzes the relations of the measured characteristics (length and height of the wing, wings area, body weight, age), in the second part I assess their possible effect on the epigamic behavior of males of Cordulegaster boltonii, specifically how they affect the intensity of searching for females. Males of this species perform distinctive scanning flights over a stream to find an ovipositing female to mate with her. I used individually marked males to quantify their performance which can be interpreted as reproductive success because more active males are more likely to meet and mate females. My work includes 3 methods of evaluating activity. The first is based on the actual number of flights, the second on the average daily order of the males (based on the number of flights in days when the males have been seen). The third method combines the average daily order with number of days when the males could be seen. In the second part of the study I evaluate the effect of the above-mentioned individual characteristics on the flight activity of males. The outcome of the GLM indicates that the only characteristic with significant effect is the age of the...
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