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Mortality of size groups of \kur{Atta sexdens} ants in breeding
WÁGNEROVÁ, Nikola
The aim of the experiment was to determine the mortality rates of different size groups of leaf-cutter ants Atta sexdens kept at the Hluboká nad Vltavou Zoo. The literature review focuses on biology, biogeography, ethology, and ecology, which are crucial for understanding this species. Several chapters are dedicated to the environmental requirements, food, and rearing methods of ants. The practical part examines the differences in head width of deceased ants between two waste piles, in relation to rearing conditions (decrease in cultivated fungus, visitor presence, and temperature in the exhibit) during different seasons of the year. The results successfully demonstrated a polymorphic division of labor associated with the size variability of worker ants. In the area where vegetation was provided as food, ants had a large head width (1,93 mm; 55-2,37 mm) compared to ants from areas without food provision (1,54 mm; 1,16-2,09 mm) (median; lower - upper quartile). Mortality varied throughout the year. As ant mortality inreased, the proportion of individuals with narrower head width increased in both waste piles.
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Vliv změn v lesních porostech na stav a vývoj populace mravence \kur{Formica aquilonia} na hoře Kleť
NĚMEC, Josef
This thesis reviews the role of red wood ants (Formica s. str.) in forest ecosystems and the impact of changes in forest environment on their population. In the practical part, it investigates the impact wind-throw Kyrill and salvage logging on large nest complex of protected Formica aquilonia ants on the Kleť mountain. This is done by combining and evaluating historical data with currently collected data of the nests distribution and their characteristics. We showed that the wind throw and subsequential salvage logging decreased the number of nests only temporarily and the impacted clear-cuts were well recolonized by F. aquilonia after twelve years. Nevertheless, the nests were smaller and their future success is questionable due to still changing environmental conditions. Interestingly, a threatened xenobiont ant Formicoxenus nitidulus was found in 23 % of the F. aquilonia nest in 2019.
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Ant food preferences (Formica genus) on the seeds with elaiosomes
ENGLICKÝ, Tomáš
The topic of the presented bachelor thesis is the determination of the ants g. Formica preference for specific seeds with elaiosomes. The ant dispersion of the seeds with elaiosomes is called myrmecochory. The theoretical part of this thesis describes the myrmecochory phenomenon in the context of the seed dispersal. The conclusion of the theoretical part evaluates considerable benefit of myrmecochory for ants and plants despite its disadvantages. The practical part of this thesis describes the experiment held with the intention to determine the preferences of the ants. The seeds with elaiosomes from five experimental plants were presented to the ants from two experimental anthills. Obtained data were processed into tables and graphs and subsequently evaluated. The results show that the ants prefer certain types of seeds. The cause for this preference is discussed.
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Host specificity of Large Blue (Phengaris arion) on Myrmica ants and its relation to habitat management in Valachia, east Czech Republic
REJMAN, Adam
Large Blue butterfly (Phengaris arion) is one of the critically endangered species in Czech Republic and Europe. Its larvae spend only a short part of the life feeding on flower buds, the rest of the stage it live inside ant nests and feeds on ant broods. I studied preferences of the solely host ant genus Myrmica in Wallachia (eastern Czech Republic), where the butterfly is still abundant. At this sites I explored nests the ants in the time of full grown larvae and pupae (unfortunately I did not find any butterfly stadium), recorded environmental characteristics of the nest vicinity and sampled workers of the ants for further determination. Except some marginal effects I did not find a clear differences in the niche of individual ant species.
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