In most species of song birds, males posses song repertoires of several different song types. Based on structural acoustic characteristics it is often possible to assign specific song types to distinct categories. These categories may be used differentiated in communication and serve different functions. For example, the production of special elements that constitute a song category might be costly and therefore, such song categories might be well suited to indicate the quality of the signaller. Playback experiments can verify whether song categories defined by acoustic similarity according to human scoring are indeed recognized as specific categories by birds, too. Nightingales have vocal repertoires of about 180 different song types per male and thus are amongst the most versatile song bird species. Some of these song types invite to be categorized according to acoustic characteristics. For example, whistle songs stick out and are hypothesised to be important to attract migrating females. Another potential category with specific communicative functions might be the so called ‘buzz song types’. Buzzes are syntactically and acoustically peculiar elements at the beginning of certain song types. These elements are produced by very fast repetitions of subunits in a narrow and rather low frequency range. We conducted playback experiments with different numbers of buzz songs to examine whether songs with buzz elements are indeed perceived as a song category by male and female nightingales. Playbacks conducted with free living spontaneous singing males did not reveal different responses to playbacks with different numbers of buzz songs. In contrast, high proportions of buzz songs did evoke stronger arousal responses in captured female nightingales. We will discuss these differences in male and female responses with regard to constraints in their production and their potential importance in close range communication.
Buzz songs as a category in communication in nightingales (Luscinia megarhynchos) [abstract]
(2012).
Buzz songs as a category in communication in nightingales (Luscinia megarhynchos) [abstract]. Bioacoustics,
Volume 21
(1):
60
-61
Abstract: