The presented thesis exploits the introduction of the yellowhammer (Emberiza citrinella) to New Zealand to study the cultural evolution of birdsong dialects in exotic populations after 140 years of complete isolation from the original source populations in Great Britain. The data are interpreted with detailed knowledge of yellowhammer past in New Zealand and of the global (Europe) and regional (Czech Republic) distribution of yellowhammer dialects. Yellowhammer song is simple and males have very limited repertoire. Since the 19th cen- tury it is known that despite its simplicity the song exhibits fascinating geographical variation; the males share the terminal notes to create mosaic-like distribution of dialects. Although this phenomenon has been known for decades and thoroughly studied, many questions remain. One of them is a suspected border between "western" and "eastern" groups of dialects. By combining information about the dialect distributions obtained from works of previous researchers with recordings from online repositories and archives we demonstrate that these groups do not create macrogeographical patterns (Chapter 6). The citizen-science project "Dialects of the Czech Yellowhammers" involved Czech cit- izens in mapping the distribution of yellowhammer dialects in the Czech territory....

Widespread extinction is a critical threat to biodiversity and is largely caused by human overexploitation of habitat and populations. A widely used and hence well studied organism group for indication of biodiversity is birds. In Europe especially, farmland specialists have suffered from intensified agricultural practices such as increase of monoculture, use of pesticides, and heavy machinery. This has been shown to be partly caused by an EU legislation called the Common Agricultural Policy (CAP). A specific type of farmland, termed High Nature Value (HNV) farmland, seems to be particularly advantageous for farmland specialist birds and makes up an important conservation target. The current study was done in the Natura2000 reserve Târnava Mare, Romania, to find out which habitat types play an essential role for occurrence of farmland species. Farmlands in Târnava Mare are highly diverse in structure, characterizing a mosaic of grassland, meadows and fields, and low-intensity farming practices. With bird point count survey data from 2015 to 2019, I evaluated the effect of different habitat types on five species listed in the Farmland Bird Indicator (FBI) and as farmland specialists: red-backed shrike (Lanius collurio), yellowhammer (Emberiza citrinella), Eurasian skylark (Alauda arvensis), Eurasian tree sparrow (Passer montanus), and common whitethroat (Sylvia communis). I compared habitat proportion in presence and absence of the species for 2019’s data with Mann-Whitney tests. They all showed significant results for meadow proportion. All species except the common whitethroat showed significant results for crop proportion, while only two species (red-backed shrike and yellowhammer) showed significant results for scrub. Independent of which habitat type was tested (meadow, crop or scrub), all species with significant result – except for Eurasian skylark with a negative relationship in crop habitat - showed a positive response to a higher proportion of the tested habitat. The same species except Eurasian tree sparrow were modelled with the generalized N-mixture model of Dail and Madsen (2011) to evaluate what is influencing abundance, recruitment rates, survival probabilities and detectability over five years. The day of the season affected the detectability of almost all species. The effect of habitat on recruitment rate and survival probability, however, could only be shown for yellowhammer. For the latter, proportion of meadow affected recruitment and proportion of reed affected survival. In conclusion, the presence of species seems to be generally higher in habitats associated with low-intensity farming on the single season scale. Over time, however, a significant effect on population dynamic parameters for the same species could not be shown for most species. This could be a result of insufficient data for each year, too few years of data, or that the tested habitat types are not affecting these parameters over time.

The inter-population geographic song variability can be found in many bird species. One of the most interesting types are dialects, characterized by sharp boundaries between populations of individuals sharing the same particular song type. Despite many years of investigation there is no satisfactory answer to the question how these borders persist over the years at nearly same sites. Distinctions between dialects allow recognition of males from different populations and could influence the territorial behaviour. Various habitats, however, degrade the sound differently; it is therefore possible that specific habitats are preferred by individuals with specific dialects. Both social interactions and acoustic properties of the locality could also be only secondary factors and the dialect distribution could be the result of the habitat distribution either in present or in recent past. In this diploma thesis, several hypotheses were tested on the example of Yellowhammer (Emberiza citrinella) - a songbird abundant in open land with simple song and easily recognizable dialects. The thorough data concerning the habitats and dialect distribution were obtained at the dialect borders at two localities in Czech Republic. The reactions of territorial males to both foreign and their own dialects were also...

A playback experiment in which a recording of vocalization is played to the tested subject and its response is observed, is a widely used tool for examining bird song and its functions. Most often only acoustic stimulus is used, but sometimes a visual stimulus is also provided in the form of a dummy. Taxidermic mounts or models made from different materials are used as the dummy. It is discussed among researchers, whether it is or is not necessary to use a dummy in experiments and how does its presence affect behavior of the tested individuals. However, only few studies directly focus on this issue and test the effect of dummies. The best way to test the effects of a dummy on passerines in playback experiments is to test the same individuals in both situations (with a dummy and without a dummy) and compare the reactions. The aim of this theses was to perform such experiments on Chiffchaff (Phylloscopus collybita) and Yellowhammer (Emberiza citrinella) males and to find out whether they would behave similarly in both variants of the experiment, or if their reaction would be enhanced in the presence of a dummy. Chiffchaffs reacted significantly more aggressively in the dummy experiment. The biggest difference was time spent by attacking the dummy and staying close to it. In Yellowhammers, the dummy...