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The influence of pasture on biodiversity of invertebrates in sub-mountain localities - coprophagous beetles
SVOBODA, Lukáš
The effect of the pasture management on dung beetle communities was studied on three sites in Šumava Mts. (South and West Bohemia). The intensity of pasturing was different: 78 cattle on the first, 106 on the second and 162 on the third pasture. The beetles were collected using pitfall traps baited by 1.5 litres of fresh cattle dung. The traps were located on each pasture. Altogether 3 traps were used per each pasture. The pitfall traps were exposed in the pasture for 7 days in monthly repetitions from April to October 2008. Totally 8725 specimen and 33 species of beetles were collected. These species belong to families Scarabaeidae,Geotrupidae and Hydrophilidae. The number of species and individuals was evaluated for each pasture, as well as seasonal dynamics and biomass distribution. The results indicate that the more intensive pasturing has the positive effect on the activity of some groups of coprophagous beetles.Other effects of the different pasture management on the beetles were not documented.
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The influence of management on biodiversity of vertebrates model groups {--} small mammals.
KOUTNÍKOVÁ, Lenka
This thesis creates a part of more extensive scientific study, which evaluates effects of different agricultural management on ecological functions and on landscapes´s water regime in source water areas of Bohemian Forest. A one of examined characteristic of catchment is biodiversity of plant and animal communities. The aim of my thesis is a comparsion of diversity of small terrestrial mammals in three catchments with similar nature conditions, but different management. Small terrestrial mammals is a group of vertebrates often used for study of enviromental state, because of their high reprodctive potential, good invasive ability and ability to indicate the changes in environmental quality. The master thesis is a follow-up to a previous bachelor thesis and extends it significantly. A teoretical part involves literary review of small mammals´s occurrence in Bohemian Forest, their micro-habitat preferences and the effect of management on the biodiversity of their communities. Practical part of the thesis contains evaluation of the results of capture-mark-release trapping, which took place from June to September of the years 2007 and 2009. In those two years 52 individuals were captured. From this amount, 7 individuals were captured twice. Captured small mammals were included into 5 species, whose occurrence in studied localities was expected. There were yellow-necked mouse (Apodemus flavicollis - 22 individuals), field vole (Microtus agrestis - 6 individuals), common vole (Mircotus arvalis - 10 individuals), bank vole (Clethrionomys glareolus {--} 2 individuals) and common shrew (Sorex araneus - 5 individuals). In the Bukový potok catchment 20 individuals were captured in 2007 and only 2 individuals in 2009. They belong to species: Apodemus flavicollis, Clethrionomys glareolus and Sorex araneus. In catchment of Mlýnský potok no individual was captured in 2007 and 10 individuals of only one species (Mircotus arvalis) were captured in 2009. In Horský potok catchment 5 individuals were captured in 2007 and 8 individuals in 2009. Three species were found: Apodemus flavicollis, Microtus agrestis, Clethrionomys glareolus a Sorex araneus. The largest positive change of abundance between 2007 and 2009 was found in the Mlýnský potok catchment. The largest fall of abundanace was in the catchment of Bukový potok. Only in catchment of Horský potok the relatively stable abundance was noticed. The thesis was supported by projects: MSM 6007665806, NAZV-QH82106 a NPV2-2B08006.
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Does butterfly mating behaviour change with phenological condition of populations?
VLAŠÁNEK, Petr
The optimization theory assumes that males of insects with separate adult generations should preferentially invest into the mating if there are the most fresh females; in other times they should save energy and focus on maintenance activities. Based on this assumption, butterfly behaviour should change with season, population density (mainly the sex ratio) and day time. To explore these assumptions, we used mark recapture data obtained from several mark-recapture studies, which contained records of behaviour of each handled individual. In total, we analysed data on 14 species, 24 ``butterfly-seasons{\crqq}, 21 737 individuals (14 228 males, 7 509 females). We subjected the behavioural data to ordination analyses controlled for weather effects. For daily patterns, morning and afternoon activities comprise mainly of maintenance activities, while mating seems to occur in middays. Regarding seasonal patterns, males of most of the species switched from mating behaviour to maintenance behaviour. No prevailing trend applied to females, in which we found both transitions from mating behaviour to maintenance activities and opposite patterns. Density predictors (sex ration, daily population size) revealed changes in mating behaviour of one sex with changing the abundance of the other sex. In conclusion, exploring mark-recapture data for behavioural patterns proved to be fruitful, but cannot fully replace studying behaviour via more traditional ethological methods.
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Individual marking of small insects and its usage in describing societies and migration of semiaquatic bugs (Heteroptera: Gerromorpha) in lentic and lotic habitats of Novohradské Mountains.
VOJÍŘOVÁ, Eva
Experiments based on the method of mark-recapture can be used for estimation of the abundance of natural populations, for monitoring dispersion of groups or individual specimens within a population using group or individual marking. Semiaquatic bugs (Heteroptera: Gerromorpha) were marked and recaptured many times in the field during research, individual marking was much less used since marking of small insects is difficult. The aim of this work is to develop a method of individual marking of semiaquatic bugs so that it would meet conditions such as durability, legibility and non affecting health of the marked specimen. Semiaquatic bugs of Aquarius paludum, Gerris lacustris, Limnoporus rufoscutellatus (Gerridae) and Velia caprai (Veliidae) species were selected as experimental organisms. Partial aims of this thesis were to try using this method to describe the abundance of the monitored population and to monitor dispersion of the selected species, both at lotic (V. caprai) and lentic habitats (water striders, family Gerridae). A new method of individual marking of semiaquatic bugs was developed on the basis of modifications of the commonly used methods. After a series of tests and in-field research, this method proved to be suitable as it met the essential conditions for marking insects. The abundance of the monitored population was estimated and dispersion of the selected species (V. caprai) in running water was described by using this method. The partial aims of this thesis were met, too. It was confirmed that individuals of the V. caprai species move between the monitored areas along the water course. This inclination to move is greater than tendency to remain in the place of release. The gained data also show conclusively higher rate of movement of V. caprai specimens in the upstream direction, compared to the downstream. The tendency of V. caprai to travel larger distance upstream than downstream, is significant too. No statistically relevant difference in either direction of the water course (up or down) in the surpassed altitude difference was confirmed. The differences in the monitored phenomena between the sexes and generations were compared as well. The differences, however, were not significant. A movement of the adults of the water cricket Velia caprai thus can be characterized as an upstream migration, common in insects of lotic habtitats. A part of the study taking place in still waters showed, that G. lacustris specimens move on the surface of the pond, but not to a larger degree than they remain in place. On the other hand, A. paludum specimens were proved to move away from the place of release rather than remaining in that place. These also overcome greater distance than G. lacustris specimens.
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Comparison of efficiency of box traps and floating rafts as monitors and trap sites for mink (Musela vison) and polecat (Putorius putorius) for population control.
BARTÁKOVÁ, Daniela
The aim of my thesis was to evaluate two methods of monitoring of the American mink and polecat, monitoring with live traps and by floating rafts. While the first method is commonly used in our country, where the second method is the pilot project here, but it has been used in the UK successfully. Observation was from August to November in 2008 and from April to November in 2009. Observation took place in the area near PP Černíč near Dačice, where were chosen 4 different habitats. All detected tracks of Mustelids found on rafts were from the American mink. It corresponds with captures, where were captured also only minks and no polecat. Occupation of rafts was higher in 2008 than in 2009 because of the eradication of mink in November 2008. In both years the highest occupancy rate in rafts was in September and the lowest in October. There were differences between habitats and number of captured minks and tracks. In compare between rafts and traps, rafts were more successful method.
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Impact of american mink on stone crayfish populations
PAVLUVČÍK, Petr
1. Impact of introduced American mink (Mustela vison) predation on endangered stone crayfish (Austropotamobius torrentium) was examined in western Bohemian middle-sized streams for two years. Mink diet selectivity and its impact on its prey abundance were been investigating as the main target of this study. 2. The mink diet was described from excrements which were found on the target areas. The importance of different types of prey was specified by their relative numeric contribution to diet. The number of hunted crayfish was elicited from the number of crayfish remains which were collected during two years. The crayfish abundance was determined by capture {--} recapture method. 3. The crayfish was most frequently observed component of mink diet. The rate of mink predation on crayfish was dependent on density of crayfish population. This observed rate was lower during winters than during summers. The mink preferred significantly longer crayfish than was the mean of this value in population. 4. Although the crayfish was important part of mink diet the trend of impact of mink on crayfish is still inexplicit. It would be important to continue in this research to determine correlation between these two species.
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Food preferences of small terrestrial mammals and their influence on biodiversity of plant communities in wet orchid meadows
CUDLÍN, Ondřej
Food preference of small rodents to consume the roots of wild plants with the emphasize on their impact to bulbs of orchid Dactylorhiza majalis has been studied on three localities during years 2002 - 2007. There were selected ten couples of plants in each plots, one individual of couple plants was protected by tin triangle. Indicated plants have been measured in the beginning (high, length and wide of the leaves and flower number) and at the end of growing period (number of capsules). Small mammals were snaptrapped for three nights in the autumn. On each locality four rows of 25 snap traps were situated, two rows through orchid plots and two without orchids. In years 2004 {--} 2007 the food preference was ascertained on studied sites. Roots of Daucus carota (as a control in year 2004) and roots of Selinum carvifolia (as control in years 2005 - 2007) and roots of tested plant were put into one rectangle "bait" of size 15 x 6 centimeters from gauze. These 50 "baits" were placed among 100 traps on each locality, every other trap, during snaptrapped of small mammals. Browsing was classified by six number scale. During years 2005 - 2007 food preference of Microtus arvalis under laboratory conditions of Science Faculty of South Bohemia University was achieved with the roots of the same species as we used during food preference on plots. During years 2006 -2007 bulbs of Dactylorhiza majalis from laboratory condition and a few idividuals from endengered meadows by revitalization of pond were added. During yeas 2006 and 2007 the contain of stomach from Microtus arvalis and Microtus agrestis, catched during autumn, was studied. Bulb destruction by small rodents during years 2002 - 2007 was not confirmed. But Microtus arvalis preferred bulbs of Dactylorhiza majalis under laboratory conditions and roots of Selinium carvifolium and Lysimachia vulgaris boths in laboratory and wet meadows. Destruction of orchid bulbs and more preferred roots of wild plants by small rodents could occur probably only in outbreaks of their population cycle. I did not observe this on studied plots. In mount of stomach from Microtus arvalis only 3% underground supply organs of plants; rest of stomach contain was consisted of aboveground green part of plants. This result was expexted, because small rodents prefere during vegetation period green part of plants.
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Spatial distribution of water bugs (Heteroptera: Nepomorpha) in fishponds: estimation and comparison based on results reached by classic method (netting) and method of light traps.
ČELOUDOVÁ, Monika
The aim of this methodically oriented thesis was to find spatial distribution of water bugs in fishpond by parallelly used two different sampling methods - classic method (netting) and light traps as well as to find, if sampling method can influence a result of ecological study by substantial way. Study was realized in the one locality - fishpond Polepšil (region: Vysočina: Moravskobudějovicko) in years 2007 and 2008. Spaces {--} transects for sampling were difined. Efficiency of water bug sampling by nett is conspicuously less than sampling by light traps. More species and individuals (in total sum of samples and in samples from individual transects too) were sampled by light traps under comparable conditions. Chemical yelow-green light of light traps was more attractive for water bugs than the pink one. Spatial preferences of some corixid species and their developmental stages were noted by application of light trap method of sampling. Light trap method of samplings brings more complete and valuable data for ecological studies of water bug communities.
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