|
|
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
|
|
|
Effect of a dummy on passerine behaviour in playback experiments
Kubátová, Hana ; Petrusková, Tereza (advisor) ; Linhart, Pavel (referee)
Playback experiment is a frequently used method for the scientific research of the bird song and its functions. A recording of vocalization is played in the territory of the tested male, and its responses are observed. Majority of the studies using playback recordings presents only the acoustic stimulus. Sometimes a dummy is also used to provide a visual stimulus. This review focuses on the effects of the dummy on the passerine behavior in the playback experiments. In the first part a comparison is made within the groups of experiments with the same field of interest. The main questions are: how often is a dummy used in these types of experiments, how do designs and results differ depending on its presence/absence and, if possible, how do researchers evaluate its use. Subsequently, I tried to compare experiments with and without dummy within same species, but because of the differences of the experimental designs and the differences in forms of presentation the results, which were often not comparable, it was difficult to make clear conclusions. Next part analyses the few available studies where both trials with and without a dummy were performed on the same individuals. The review shows that the dummy allows tested males to express additional behavioural patterns, which can be noted by the...
|
guest ::
