The yellowhammer (Emberiza citrinella) is a common bird of open areas whose song exhibits easily distinguishable dialects. The dialects are tied to the final part of its song. Some, especially older publications claim that yellowhammer's dialects can be divided into two broad groups with predominantly Eastern and Western European distribution, with a borderline intersecting Central Europe. Until recently, yellowhammer dialects have only been thoroughly researched in Denmark and in some parts of Germany. In the Czech Republic, a detailed study was carried on in connection with the"Bird of the Year"campaign, during which the general public was involved in collecting song recordings at various localities. Thanks toa project called "Czech Yellowhammers Dialect", more than 2600 recordings from throughout the Czech Republic were collected within three years. The recorded songs were then classified into one of the seven traditionally acknowledged groups; some new, not yet documented ones were also discovered. The distribution of the dialects generated a dialect mosaic with a clearly established borderline between individual dialects. Mixed singers were found along the borderlines. A borderline between two dialect groups, crosscutting Western Bohemia, was also found. It was proved once again that for a success of...

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....

6 ABSTRACT Bird song is a sexually selected trait that is crucial for mate choice and for maintenance of pre-mating reproductive barriers. Secondary contact of closely related and partially reproductively isolated song bird species may result in changes in their songs; these can either diverge and strengthen the reproductive barrier between the two species, or converge and contribute to mixing of their gene pools. The Thrush Nightingale (Luscinia luscinia) and its congener Common Nightingale (L. megarhynchos) may serve as model species suitable for studying these phenomena. In their secondary contact zone, an interspecific hybridization has been documented, as well as convergence of songs of Thrush Nightingales caused by copying of heterospecific songs. Such copying may be a result of erroneous learning of species- specific songs or by genetic introgression. We tested these hypotheses by simultaneous analyses of DNA and song recordings of both species from allopatry (Czech Republic and northeastern Poland) and sympatry (central Poland). Comparisons between our recordings and a catalogue of songs recorded in a Common Nightingale population from allopatry (Germany) confirmed that most of Thrush Nightingale males from the sympatric region were 'mixed singers' that use Common Nightingale phrases in their...

Birdsong is one of the most fascinating communication tools in the animal kingdom, whether it is used for attracting a mate or in territory defense. In my dissertation, I present evidence that we can successfully study the role of birdsong in territorial behaviour, its seasonal variability, and ultimately its role in evolutionary processes thanks to modern bioacoustic and ecoacoustic approaches. By combining the bioacoustic approach with molecular analyses, I demonstrate that in the model system of two closely related passerine species, the heterospecific song convergence in their secondary contact zone is based on cultural transmission, and not on interspecific hybridisation and/or gene introgression. My dissertation further extends into the tropical zone, which is generally characterized by less pronounced environmental seasonality compared to the temperate zone. The study of potential seasonality in singing activity and the proportion of vocalizing species in this zone therefore requires year-round monitoring, which is possible thanks to the quite recent development of automated recording units (ARU). First, we confirmed that using ARU provides very similar estimates of community composition, species richness, and abundance to traditional field methods (point counts) in the specific conditions...

Birdsong is one of the most astounding natural sounds which profoundly shaped our evolutionary thinking since the 19th century. Despite a strong interest in birdsong for over 100 years, our understanding of birdsong ecology and evolution over large spatial and phylogenetic scales is still very fragmentary. Answering many basic questions requires a global synthesis covering vast diversity of extant bird species and adoption of multidisciplinary approaches. In presented dissertation thesis, my co-workers and I have explored important patterns in macroecology and macroevolution of song in passerines (Order: Passeriformes), the most diverse and widespread bird order. We have focused on three key song phenomena: (1) song complexity, (2) song frequency and (3) the presence of song in female birds. We have exploited birdsong "big data" available on public citizen science databases and other open sources in order to fill several important gaps in the current knowledge. These data were analysed by a combination of phylogenetically-informed cross-species analyses and spatial macroecological approaches. Since the publication of Darwin's seminal work, elaborated songs are generally agreed to be the result of sexual selection. We developed a simple but reliable song complexity metric to explore a global diversity in...

Birdsong is one of the most astounding natural sounds which profoundly shaped our evolutionary thinking since the 19th century. Despite a strong interest in birdsong for over 100 years, our understanding of birdsong ecology and evolution over large spatial and phylogenetic scales is still very fragmentary. Answering many basic questions requires a global synthesis covering vast diversity of extant bird species and adoption of multidisciplinary approaches. In presented dissertation thesis, my co-workers and I have explored important patterns in macroecology and macroevolution of song in passerines (Order: Passeriformes), the most diverse and widespread bird order. We have focused on three key song phenomena: (1) song complexity, (2) song frequency and (3) the presence of song in female birds. We have exploited birdsong "big data" available on public citizen science databases and other open sources in order to fill several important gaps in the current knowledge. These data were analysed by a combination of phylogenetically-informed cross-species analyses and spatial macroecological approaches. Since the publication of Darwin's seminal work, elaborated songs are generally agreed to be the result of sexual selection. We developed a simple but reliable song complexity metric to explore a global diversity in...