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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Sledování hnízdních parametrů rákosníka obecného \kur{(Acrocephalus scirpaceus)}na náhodně vybraných lokalitách v CHKO Třeboňsko. / Observation of nesting parameters of reed warbler \kur{(Acrocephalus scirpaceus)} at accidentally chosen localities in PLA Trebonsko.

ZÁRUBOVÁ, Marie January 2009 (has links)
The aim of this work was to realize some regular monitoring of nesting occurrence of Reed-warbler (Acrocephalus scirpaceus), measure all nesting parameters of each found nest {--} nesting placing in a vegetation, characteristic of vegetation, running of nesting {--} and explain which factors should play a role in a seizing of these localities {--} to explain a measure of nesting predation by way of artificial nests. Statistically analyze these parameters and find some dependence and relations which should influence running or success of nesting.
22

Akustická detekce potencionálního predátora u koně domácího (Equus caballus) / The acoustic detection of potential predator in domestic horse (Equus caballus)

Vidimská, Tereza January 2017 (has links)
Equidae belong to a group of large herbivores, which survival in natural environment depends beside others on their capability of fast predator recognition and detection. They can sensually recognise a possible threat in advance and react by immediate escape, which increases their survival. Also domestic horses still show very sensitive reaction to sudden (unexpected) stimuli. So we assume, that the ability to detect predator immediately is conserved despite of the long domestication process. The supportive indirect evidence is given by the successful breeding of the feral herds all over the world. However, studies showing the direct reaction of domestic horse toward the canids (as the most common predators), are still absent. Aim of the work was to find, if the horses (Equus caballus) could recognize acoustic sign of dogs like predators and if they could recognize the level of potential threat according to the number of predators, similarly as their wild ancestors. The recordings of barking of big dog breeds were obtained and modified. The final recording contained the set of barking coming from one individual or three different. The recording was played to the experimental horses, under controled conditions, together with white sound as a control. The reactions were recorded. Altogether 12 horses out of...
23

Akustická detekce potencionálního predátora u koně domácího (Equus caballus) / The acoustic detection of potential predator in domestic horse (Equus caballus)

Vidimská, Tereza January 2018 (has links)
Equidae belong to a group of large herbivores, which survival in natural environment depends beside others on their capability of fast predator recognition and detection. They can sensually recognise a possible threat in advance and react by immediate escape, which increases their survival. Also domestic horses still show very sensitive reaction to sudden (unexpected) stimuli. So we assume, that the ability to detect predator immediately is conserved despite of the long domestication process. The supportive indirect evidence is given by the successful breeding of the feral herds all over the world. However, studies showing the direct reaction of domestic horse toward the canids (as the most common predators), are still absent. Aim of the work was to find, if the horses (Equus caballus) could recognize acoustic sign of dogs like predators and if they could recognize the level of potential threat according to the number of predators, similarly as their wild ancestors. The recordings of barking of big dog breeds were obtained and modified. The final recording contained the set of barking coming from one individual or three different. The recording was played to the experimental horses, under controlled conditions, together with white sound as a control. The reactions were recorded. Altogether 12...
24

Interakce nepůvodních druhů korýšů ve vodách ČR: Lovec nebo kořist? / Interaction of non-native species of crustaceans in Czech waters: Predator or prey?

ŠVAGROVÁ, Kateřina January 2017 (has links)
This diploma thesis deals with non-native species of crustaceans, which are already present not only in Europe but also successfully inhabit the territory of the Czech Republic. The species that this work deals with is the signal crayfish (Pacifastacus leniusculus), marbled crayfish (Procambarus fallax f. virginalis) and the killer shrimp (Dikerogammarus villosus). The main goal of this study was to demonstrate the ability of killer shrimp to attack and prey on the crayfish eggs and hatchlings of above mentioned species, which were used not only for theuir presencein Czech Republic but also as model representatives of families Astacidae and Cambaridae. It was therefore the confirmation of high aggressiveness of killer shrimp and point out, that this species is capable of negatively influencing even the bigger invertebrates by direct predation on their early developmental stages. Another aim was to assess whether the killer shrimp can be a suitable prey for a crayfish. As the experiments have shown, killer shrimp is able to predate on crayfish eggs and hatchlings even directly on females abdomens wehre they are incubated and protected. The results confirmed the theory of killer shrimp hazards to aquatic ecosystems and its potential to directly influence the populations of larger organisms. At the same time, it has been found that killer shrimp may be a suitable prey for adult and subadult individuals of signal crayfish and adults of marbled crayfish.
25

Antipredační chování surikat (Suricata suricatta) ve skupině chované v ZOO Jihlava. / Antipredation behaviour of meercats (Suricata suricatta) in the group kept in ZOO Jihlava.

ZÍTKOVÁ, Jana January 2012 (has links)
Meerkat (Suricata suricatta) is a mongoose species from South Africa. Insects are the primary food sources of their diet. Meerkat lives in groups of 2?30 individuals with a developed social structure. The group consists of a dominant pair and a different number of helpers of both sexes, which are involved in various forms of cooperation, for example care for cubs, guard service and maintaince of burrow. Meerkats are at risk of predation by mammalian predators, avian predators and snakes. One meerkat always seems to be a sentry and stands guard to keep the gang safe. When the guard senses danger they give a warning bark and the other members run for cover into their burrow. This study was done from June to September 2011 in zoo in Jihlava on a group of meerkats, which consisted of 13 individuals. There was used the method of direct observation by a scanning behaviour (behaviour sampling). Observation was specialized on sentinel behaviour. The main aim of this work was evaluate the results of observation and then compare this results with behaviour in the wild. By monitoring was demonstrably found, that dominant individuals contributed to guarding more frequently and the longest time and the juveniles contributed at least. There wasn´t set order in guarding. The most often was individually guarding or guarding in a group of 2 or 3 individuals.
26

Ekologie lasicovitých šelem / Ecology of mustelids in the Central European landscape

ŠÁLEK, Martin January 2009 (has links)
Ph.D. thesis is focused on different aspects of ecology of several mustelid species in the Central European landscape. Particularly, nest predation, habitat and resting sites selection, predator-prey interactions as well as impact of fragmentation and urbanization on mustelids were described in 8 published papers or manuscripts.
27

Složení společenstva bakterioplanktonu v závislosti na kompozici fytoplanktonu v období jeho jarního vrcholu / Relating bacterioplankton composition to shifts in phytoplankton community dynamics during its spring bloom period

HAVLIŠOVÁ, Tereza January 2011 (has links)
Over the period of the spring phytoplankton bloom (March-May 2009), an intensive sampling program was conducted at 2 sampling depths (0.5 m and 1% PAR) located at lacustrine zone of the canyon-shaped, meso-eutrophic Římov reservoir (Czech Republic). Changes in the production and community dynamics of epilimnetic bacterioplankton, studied by means of group-specific rRNA-targeted oligonucleotide probes, were related to shifts in composition and activity of phytoplankton, and to remarkable changes in total protistan bacterivory. It was documented that particular groups of bacterioplankton responded differently to: (i) major shifts in phytoplankton composition and its activity and to (ii) changes in overall protozoan grazing pressure.
28

Inkubační chování rybáka dlouhoocasého Sterna paradisaea v extrémních klimatických podmínkách severské tundry / Incubation behavior of the arctic tern Sterna paradisaea in extreme conditions of northern tundra

Hromádková, Tereza January 2015 (has links)
Short breeding period and harsh climatic conditions are major limiting factors to which birds have to adapt in northern tundra regions. Despite this fact, dozen species of birds annually migrate into these regions to increase their chances to breed successfully. My diploma thesis focuses on incubation behaviour of the Arctic tern (Sterna paradisaea). The research for my thesis took place on the Norwegian archipelago Svalbard, in two particular locations: Adolfbukta and Longyearbyen. By using the method of continuous video recording, I described incubation behaviour of this specie in detail. Human activity is very different on each of Adolfbukta and Longyearbyen. On site Adolfbukta study was conducted during seasons 2012 and 2014, both with different predation pressure. Having known that, I could evaluate the impact of human activity as well as the impact of different predation pressure on incubation behaviour and breeding ecology of Arctic tern. The presence of human close to the colony had significant effect on incubation behaviour. Due to higher disturbances, incubating birds tended to leave their nests more often, attention paid to the nest was smaller and calm incubation (sleeping on the nest) was shorter by a half. Human activity had no effect on other displays such as average clutch size or...
29

Vliv biotických interakcí na populační biologii Sanguisorba officinalis / The influences of biotic interactions on population biology of Sanguisorba officinalis

Větvičková, Anna January 2021 (has links)
Plants can interact with many different organisms on many trophic levels in their life. In this thesis I investigated how three biotic inertactions, powdery mildew infection, caused by Podosphaera ferruginea, predispersal seed predation by Dusky Large Blue (Phengaris nausithous) and Scarce Large Blue (P. teleius) and deer grazing affect life cycle and population biology of the Great Burnet (Sanguisorba officinalis L.). I also analysed their preferences of environmental conditions. Most of studied plant populations growth rates (λ) were lower than 1 and population decreased, but quite surprisingly for more populations vegetative reproduction was more important than reproduction by seeds. All intraction mentioned above affects more generative reproduction, and thus their influence on Great Burnet population dynamics is low, even with modelled maximal possible effect. Environment conditions analysis showed that powdery mildew occurs on sites with more flowering individuals, where spreading is very easy, butterflies preferred high, well noticeable flower heads grown high above other vegetation and host ant presence. For host ants' presence model locality was only significant variable.
30

Ekologie lesního společenstva ptáků na Papui Nové Guinei

CHMEL, Kryštof January 2017 (has links)
The thesis addresses several aspects of ecology of lowland rainforest avifauna in Papua New Guinea. It describes spatial and temporal distributional patterns of abundance and diversity of bird community and different feeding guilds. More specifically, spatial patterns were explored in relation to topography, tree species composition, forest structure including vertical forest strata and inter-specific associations. The thesis also focuses on nest survival in continuous and fragmented forest, particularly in relation to nest predation.

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