• The Korean Journal of Zoology
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• v.38 no.4
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• pp.443-448
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• 1995

Playback experiments were performed to clarify the degree of song recognition using inter - and intra-populatlon songs of Bush Warbler at Cheongwon, Chungbuk area. Six territorial males were strongly responded to inter- as well as intrapopulation songs. Their responses to the inter- and Intra-population songs were not differed significantly in all measures of latency time, staying time, and closest distance. This result imply that Bush Warbiers in the region did not discriminate the difference between intra- and inter-population songs. It may be the reason that the regional males have little Interactions In song exchange with neighbors by keeping a long Individual distance. In order to investigate the signal value as species recognition releaser, playback of partial songs, prepared from tow distinct regional populations of the spedes were presented to males of the study area. The partial songs presented were made of two portions for each presentation, a whlsde portion only, and a complex syllable portion only. Territorial males responded stronger to the complex syllable portion than the whistle portion of the song. This result indicate that the complex syllable portion conveys more information on the species recognition. As 'releaser' hypothesis suggested formerly, a function of the complex syllable portion In Bush Warbler song is understood In which conveys most spedesIdentifying information. Thus, the result of this playback experiments supports the releaser hypothesis.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.282-291
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• 1996

The song of the bush warbler, Cettia diphone, consists of an introdudory whisde portion and a complex ending syllable portion. In bush warbiers, a song with two or fewer notes in the whistle portion is classified as an a song mode, while a song with three or more notes in the whistle portion as a $\beta$ song mode. Although some variations occur in mode seledion by individuals and populations, the proportion of a mode songs to total songs is 55% (range 51.6-58.7%) on average. The a mode has a higher dominant frequency in the whistle portion than does the $\beta$ mode, but the number of syllables m the complex ending syllable portion is fewer. Bush warbler mode sequences are defined as $\alpha$$\alpha$, $\alpha$$\beta$, $\beta$$\alpha$ and $\beta$$\beta$ mode sequences. In order to test the hypothesis that song modes and mode sequences play a role in the defence of territory in Jeju and Wando populations in the south-coastal geographic song variation group, playback experiments were executed. Mode sequences differed between naturally produced songs and songs produced in response to playback for two populations. In particular, for birds in the Wando populations our results indicate that the use of song modes may be affeded by habitat, singing site and type of territory, and further propose that particular mode sequences may play a more important role than song mode in vocal interadions.

• Animal cells and systems
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• v.3 no.2
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• pp.149-151
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• 1999

It has been suggested that the bush warbler (Cettia diphone borealis) uses different song types in various situations. We analyzed song features and conducted playback experiments in order to reveal the function of songs of the bush warbler. Two song types were identified. The short song type has a shorter song duration than that of normal song types and consists of only one or two syllables. Due to its short syllable and low amplitude of the whistle portion, we were able to discriminate the short song type (S song type). from the normal song type (N song Type). In the playback experiments, bush warblers sang high rates of short song type for the first three minutes after playback. After 6 minutes of playback, males changed to singing normal songs. These results suggest that the short song of the bush warbler may function to threaten or drive off intruding males.

• The Korean Journal of Ecology
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• v.19 no.2
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• pp.141-149
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• 1996

This study was to examine the occurrence of geographic song variation and its pattern of transitional direction among bush warbler populations distributed in Korea and Japan, Bush warbler songs (n=283) of 25 males from Cheongwon and Jeju, Korea, and from Chiba, Japan were analyzed. Chiba individuals had more song types and had the higher dominant frequency and longer duration of the introductory whistle portion than Cheongwon and Jeju individuals. In measure of eight song parameters, the parameters constantly showed a decreasing or increasing tendency. The constant tendency showed direction related with the geographic location from Chiba to Cheongwon. The difference in song parameters between Cheongwon and Chiba populations was the greatest in comparison to that of other sets of geographic populations. The degree of discrimination among the three populations was 92.00%. These results indicate that there is a geographic song variation between bush warblers of Japan and Korea, and that the song transition has been directed from Chiba (Japan) through Jeju to Cheongwon (Korea).