|
|
Yellowhammer dialects and citizen science
Diblíková, Lucie ; Petrusková, Tereza (advisor) ; Linhart, Pavel (referee) ; Osiejuk, Tomasz S. (referee)
Bird dialects, the cultural phenomena that can be linked to migration, gene flow, speciation and cultural evolution, have been studied extensively. The yellowhammer Emberiza citrinella, a common European bird with a simple song and long singing season, has been a model species for studying dialects for decades. In this thesis, I collate several studies that benefited from citizen science approaches to push this field forward. First, we have compiled and unified information on yellowhammer dialect distribution scattered in numerous publications, and unified different dialect nomenclatures used in the past. We supplemented this with data available thanks to volunteers contributing to public databases and other online sources, and demonstrated that the continental distribution patterns of yellowhammer dialects do not support the existence of broad, geographically distinct macrodialect groups as previously believed. In 2011, as part of the Bird of the Year campaign of the Czech Society of Ornithology, we launched a year-long public awareness project "Dialects of Czech Yellowhammers". Its first year's results exceeded expectations in quality and quantity, so a one-year, conservation-focused citizen science project became a long-term, investigative one. In subsequent years, improvements to the web user...
|
|
|
Use of individual acoustic monitoring to detect changes of Yellowhammer song in time
Kouřil, Jan ; Petrusková, Tereza (advisor) ; Rubáčová, Lucia (referee)
Birdsong transmitted through populations and generations via social learning is one of the most famous and well-studied examples of culture in animal kingdom. Over time song may change as part of so-called cultural evolution which can be monitored in many ways. However, the most effective way to reveal the mechanisms driving the change of song over time is individual monitoring. In case of songbirds ringing and other invasive methods are the most usual methods for it. But these have issues like the need to capture the bird or difficulty of reading the rings in some environments. But if the vocalizations of a bird species are individually specific and stable over time, it is possible to monitor individuals of that species using only recordings of their vocalizations by individual acoustic monitoring (IAM). However, this non-invasive, fast and effective monitoring method is still very rarely used in birds. The aim of this study was to confirm that the repertoire of the initial phrases of the Yellowhammer (Emberiza citrinella) is individually specific and stable between years, making it a suitable species for individual acoustic monitoring. I confirmed this by visually analyzing spectrograms of recordings of 107 males detected over three years. I also verified my visual identification using two...
|
|
|
Yellowhammer as a model species for studies on passerine dialects
Diblíková, Lucie ; Petrusková, Tereza (advisor) ; Procházka, Petr (referee)
Even though birdsongs and bird dialects have been subject to considerably intense scientific research, the domain of bird dialects is still worth attention of scientists. There is a large number of hypotheses about the emergence of bird dialects which separately or combined explain their origin. Dialects can be classified on the basis of the structure of a birdsong which they are related to or according to a geographical scale (micro and macrodialects). Research on bird dialects belongs to such type of studies that require great amount of data and thus large amount of time and finance is needed. Nonetheless, this obstacle can be avoided by involving general public into the research, however choosing a suitable model species is necessary. Yellowhammer (Emberiza citrinella), which was chosen in this study, is undoubtedly a convenient species for its common occurrence and distinguishable birdsong. Yellowhammer males sing during a large part of the season and their dialects can be easily recognized. Moreover, some scientists differentiate between macrodialects, that should be divided across western and eastern Europe, and could be used to make the research more attractive for general public. Till now yellowhammer dialects have been thoroughly explored in Denmark and in some parts of Germany, but in other...
|
|
|
Effect of a dummy on behaviour of Yellowhammer and Chiffchaff males in playback experiments
Kubátová, Hana ; Petrusková, Tereza (advisor) ; Veselý, Petr (referee)
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...
|
|
|
Signaling function of plumage coloration in Yellowhammer males
Kauzál, Ondřej ; Petrusková, Tereza (advisor) ; Šálek, Miroslav (referee)
Sexual selection theory tries to explain evolution of apparently useless traits which mainly developed in males of numerous species. One such trait is also rich and vibrant coloration, typical for many of the bird species. These traits are difficult to be falsified, and therefore they honestly signal quality of the individual. Carotenoid coloration reflects the health condition and melanin coloration the social status, even though this traditional division might not be as strict according to the latest studies. Apart from these ways of maintaining honesty, recent studies are focusing more also on the effect of hormones, mainly two steroids: male sexual hormone - testosterone -, and the "stress" hormone - corticosterone. Both hormones could positively influence male's sexual traits such as ornamental coloration. On the other hand, elevated levels of these hormones possess risk to the organism (higher energetic expenditure, chronic stress), therefore also might potentially become costly. Using photographs of birds in standardized conditions as well as spectrophotometry I analyzed the plumage coloration of males of the Yellowhammer (Emberiza citrinella). Concentrations of testosterone and corticosterone deposited in feathers were analyzed using the LC-MS/MS. Also, for males in breeding season 2015,...
|
|
|
Among-population variability in yellowhammer songs: causes and consequences
Bílková, Jana ; Petrusková, Tereza (advisor) ; Reif, Jiří (referee)
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...
|
|
|
Yellowhammer as a model species for studies on passerine dialects
Diblíková, Lucie ; Petrusková, Tereza (advisor) ; Procházka, Petr (referee)
Even though birdsongs and bird dialects have been subject to considerably intense scientific research, the domain of bird dialects is still worth attention of scientists. There is a large number of hypotheses about the emergence of bird dialects which separately or combined explain their origin. Dialects can be classified on the basis of the structure of a birdsong which they are related to or according to a geographical scale (micro and macrodialects). Research on bird dialects belongs to such type of studies that require great amount of data and thus large amount of time and finance is needed. Nonetheless, this obstacle can be avoided by involving general public into the research, however choosing a suitable model species is necessary. Yellowhammer (Emberiza citrinella), which was chosen in this study, is undoubtedly a convenient species for its common occurrence and distinguishable birdsong. Yellowhammer males sing during a large part of the season and their dialects can be easily recognized. Moreover, some scientists differentiate between macrodialects, that should be divided across western and eastern Europe, and could be used to make the research more attractive for general public. Till now yellowhammer dialects have been thoroughly explored in Denmark and in some parts of Germany, but in other...
|
guest ::
