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Functions of a female song in passerines
Kubíková, Tereza ; Petrusková, Tereza (advisor) ; Mikula, Peter (referee)
Female song in passerines was overlooked for a long time because it was assumed that only males sang, even though the first records of female singing appeared at the end of the 19th century. The sporadic singing of females was usually explained by an increase in the level of sex hormone but in reality, females probably sing for the same reasons as males, i.e. to defend their territory, attract a mate, or prevent extra-pair copulation. These functions of female song were discovered when ornithologists began to focus more on tropical songbirds. In fact, in the tropics, many species show sexual dimorphism, making distinguishing females from males easier. Partners also make long-term partnerships and they usually defend year-round territories together so it is advantageous for them to be synchronized in their songs too. For this reason, females sometimes join their partners in singing to make duets. Today, the female song has been recorded in many temperate songbirds and the number of species is gradually increasing but it is probably still overlooked in many species because females can be mistaken for males or because they sing only for short periods of time so it can be more difficult to capture their song. Keywords: female song, birds, function of female song, temperate zone
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Cultural evolution of birdsong: Changes of Tree Pipit vocalization in year-to-decade temporal scales
Çetinkaya, Belfu ; Petrusková, Tereza (advisor) ; Musilová, Zuzana (referee)
Social learning gives rise to culture, which is defined as socially learned behaviors that are shared among members of a community and persist over generations. Song of the passerines is one of the most studied and well-known examples of culture, as young birds acquire their species-specific songs through social learning. In addition, the song or its structures, such as syllable types, can evolve through various mechanisms, such as learning biases or copying errors, during this transmission between and within generations and across populations. The aim of the study was to uncover the possible mechanisms behind the song evolution of Tree pipits. Altogether 207 males were recorded, and the study population was continuously monitored for 12 years-period. It was revealed that learning bias could be one of the possible mechanisms that play a role during song transmission of the studied population, since dominant syllable types were stable over the years and survived until 2022. Moreover, the function of dominant syllable types such as species-specific recognition could lead to this conservative pattern. Also, there were some syllable types other than the dominant ones that also survived over the years. The longer survival of these syllable types could be due to a preference for learning local syllable...
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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...
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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...
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Use of individual acoustic monitoring to study endangered species - case study on the Meadow Pipit
Helmbold, Lily Carolin ; Petrusková, Tereza (advisor) ; Beran, Václav (referee)
1 Abstract Monitoring is an essential part and prerequisite for successful conservation measures. Methods used for decades for bird monitoring provide information about species richness and partly use acoustic signals, an important communication tool not only for birds. Unique features of song allow idividual identification, but this knowledge has not yet been captured by traditional monitoring methods, but it is very important for a deeper understanding of the ecology of monitored animals. To identify individuals based on vocalisation, science is increasingly turning to a method called individual acoustic monitoring (IAM), based on unique differences in vocalisation. IAM has so far been used for simpler songs, but its applicability to complex vocalizations would be a valuable complement to traditional monitoring methods. In this paper I therefore address the question of the applicability of individual acoustic monitoring for on-site conservation measures. The study was conducted on a model species of songbird, the meadow pipit (Anthus pratensis), and individuality in song was assessed by subjective analysis of the syllable repertoires of singing males. This is an alternative approach that considers shape similarity instead of discrete syllable values. A total of 168 singing males of three European...
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Signals of escalating aggressive motivation in birdsong
Škvařilová, Anežka ; Petrusková, Tereza (advisor) ; Schneiderová, Irena (referee)
Singing plays a vital role not only in the communication of songbirds, but it also holds a variety of information about the singer. For example, singing can reveal a singer's age, physical ability, or individuality. At the same time, it can tell how willing the singer is to attack. For this purpose, males use signals of escalating aggression, which they apply primarily during territory defence, using them to inform each other of their motivation to fight. There are several characteristics in birdsong that are considered to be signals of escalating aggression. These include song type switching, song type matching, overlapping, song length, song rate and soft song. It appears that the nature of conflict signalling is highly variable across species. This bachelor thesis analyses these singing characteristics in depth and evaluates, according to established criteria, whether they can be considered as signals of conflict escalation in different songbird species. Keywords: signals of conflict escalation, aggressive behaviour, territorial interaction, playback, singing characteristics, attack
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Female choice based on colouration and song performance in passerines with sexual dichromatism
Kauzál, Ondřej ; Petrusková, Tereza (advisor) ; Svobodová, Jana (referee)
This thesis is about female mate choice and its influence on two most typical phenotype characteristics of sexually dimorphic passerines (Aves, Passeriformes): their colouration and song. This thesis reviews a range of scientific papers focused on this problematic. Results of these papers show that both colouration and song can serve as an honest signal and give information about health, condition and other characteristics of its bearer. Many papers also indicate that females put such male signals into account when choosing a mate. Special emphasis in this thesis is put on papers which dealt both with colouration and song. Although the number of such papers is very low, it is clear that the quite widely accepted opinion that brightly coloured birds do not sing quite melodic songs and vice versa is generally not quite correct. The biggest problem in the study of female mate choice is the lack of papers which dealt with more than one phenotype characteristics.
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Mechanisms enabling individual recognition of passerine birds
Caha, Ondřej ; Petrusková, Tereza (advisor) ; Vokurková, Jana (referee)
Vocalization allows birds to communicate over long distances or in environments, where can be difficult to detect visual signals. Vocalization can be divided into songs and calls. Song may inform a listener of signal about species, sex, male quality, aggressive motivation and also about singer's identity. Recognition of different individuals is very valuable ability that is commonly used during territorial interactions among males. Correct identification of males, that pose different threat, enable to respond adequately to the situation and save energy or to avoid injury in potential conflict. The ability of individual distinguishing based on song was demonstrated by using playback experiments for many passerines, but it was rarely revealed the way of such identification. This review deals with the issue of neighbour-stranger experiments that confirm the ability of passerines to discriminate between neighbours and strangers. Further, it focus on structures or characteristics of birdsong enabling individual recognition of passerines and their possibly use for individual acoustic monitoring.
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Functions of different song types and song structures in songbirds
Pišvejcová, Iveta ; Petrusková, Tereza (advisor) ; Linhart, Otomar (referee)
In this review I summarize information about different types of song and its structures in which has been well documented their context of use. I have tried to find out, if there are some generally valid rules. The work is aimed at Passerines (Passeriformes) males living in the temperate zone. They sing the most intensively after their arrival on breeding grounds in early spring. Depending on a species and moreover an individual, the song might differ in structure, time and frequency parameters. Some species use complex songs, and change the way of its production according to attending audience. In such cases, the length and versatility of the song (the number and variability of syllables) may reflect the quality of a male. On the other hand some species with a simple song use different criteria to assess the singer quality. The individuals then differ in the way of song production or just in use of particular structures. For example, wide frequency range and length are considered to be energy-demanding for production, and so it could be a suitable indicator for a male quality. Short syllables produced at a faster rate can be not only production-demanding but can also indicate aggression. In general, we can estimate the function of a produced song according to "mating status" (before and after pairing) and...
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