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Boar vocalizations and their potential role in sexual selection
Roreitnerová, Daniela ; Linhart, Pavel (advisor) ; Schneiderová, Irena (referee)
The aim of this research was to gather existing knowledge about vocalizations of boars and their potential role in sexual selection. Few studies mainly from the 70s and 80s of the last century suggest that the so-called love song, emitted by males during courtship, could act as a stimulant that triggers mating. However, I did not find any evidence that boars significantly use calls in fights. Most studies deal with pig vocalization in a different context. For this reason, I tried to look at the studies of pig relatives - even-toed ungulates - to better evaluate the potential role of boar vocalizations in sexual selection. In their case, the influence of the calls on the sexual behavior of females and competing males was reported. It is possible to conclude that the role of boar vocalization is probably not that important as in red deers, for example, because boars use calls in short range communication. On the other hand, stimulatory effect on females was found in other species too. Further studies are needed to understand possible function of boar vocalizations that could be used for example in pig breeding to improve the effectiveness of artificial insemination of sows. Powered by TCPDF (www.tcpdf.org)
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Bird of the Year 2011: involving public in the analysis of regional variation of bird songs
Diblíková, Lucie ; Petrusková, Tereza (advisor) ; Reif, Jiří (referee)
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...
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Vocalization of two nightingale species in their hybrid zone
Vokurková, Jana ; Petrusek, Adam (advisor) ; Osiejuk, Tomasz S. (referee)
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...
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