摘要:

Kerivoula pellucidais a small (4.5 g) vespertilionid bat, which forages in the understorey of tropical rainforests in Southeast Asia. Most echolocation signals are characteristic for the subfamily (very high-frequency, broadband FM calls (sweeping down from 178 kHz to 58 kHz) of low intensity and short duration (< 3.0 ms)), but this species also produces stereotypical calls of a markedly different structure. The arrangement of signal elements in these calls is unusual, and we present here a detailed analysis of calls from thirteen adult individuals (nine males and four females). These multiharmonic calls are of much lower frequency (fundamental peak frequency of 36 kHz), higher intensity and longer duration (12.0 ms) than the orientation calls, and are composites comprising a long quasi-constant frequency (QCF) syllable followed by an upward frequency modulated sweep (UFM). From considerations of signal design and preliminary field observations, we consider possible functions of these calls.

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753446

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

To test the mate attraction hypothesis and the territory defence (establishment) hypothesis in the WhitethroatSylvia communis, I studied the pattern of vocal activity in the different phases of the breeding cycle in 1995 and 1996. Furthermore the response of unmated and mated males to playback was studied in 1997. The low “perch song” activity and “flight song” activity of mated males compared to unmated males suggest that song was used in mate attraction. The perch and flight song activity in the morning tended to increase during the season but only significantly in 1996. The perch song was also used in territorial defence as suggested by unmated males responding to the playback with increased song activity. The diving song was apparently used in courtship of the female, since most diving songs were directed towards females. In mated males thedscharp-call was the most frequent vocal behaviour and mated males primarily used this call in response to playback. The more discreet vocal behaviour of mated males suggests that males use a silent strategy.

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753447

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Recordings of vocalizations in the presence of minke whalesBalaenoptera acutorostratawere made from a bottom-mounted hydrophone in the St. Lawrence Estuary, a feeding area for some members of the Northwest Atlantic population. Minke whale activity was observed from a hillside hut and notes were taken with regard to position and swimming direction throughout each recording. The vocalizations were correlated consistently with the occurrence of minkes and sequential sound levels were commensurate with the whale's relative proximity to the hydrophone. Minke calls were heard in 51% of the recordings examined in detail; calling rates were low (0.1 sounds/min—3.6 sounds/min with multiple individuals). The predominant call was a 0.4 sec downsweep in frequency, beginning at 100–200 Hz (median = 118 Hz) and ending below 90 Hz (median = 80 Hz). The change in frequency was variable, between 20 and 70 Hz (median = 42 Hz). Frequency and temporal characteristics of the vocalizations were similar to those recorded from Antarctic minkes by Schevill and Watkins (1972). Comparisons of the minke downsweeps with those from the closely related finback whaleB. physalus, which is also common in the area, indicated that minke whale calls had higher initial frequencies, greater changes in frequency, and shorter call durations.

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753448

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Some acoustic signals produced by small insects are very low in amplitude and attenuate rapidly with distance. To achieve high quality recordings with such signals, the use of specialised microphones or of sound insulation chambers is necessary. This paper presents a simple and efficient method for the recording of acoustic signals emitted by small sources. Its principle is based upon the use of two simultaneous digital recordings from two microphones: one records the ambient noise while the other records the ambient noise plus the signal to analyse. Both these recordings are converted into digital files and then a simple subtraction between the two isolates the signal with a good signal-to-noise ratio. With this method of background noise removal, the recording of low amplitude sounds in an uninsulated room with common microphones becomes possible. We have applied this method to the study of 12 complete courtships ofDrosophila melanogasterand particularly to the analysis of pulse sounds produced by the male in presence of a female. The study focuses mainly on the rhythm of production of pulse trains over the course of the courtship.

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753449

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753450

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Syrinx is a newly developed PC-based software package designed for interactive playback of animal vocalizations and for digital sound recording and analysis in the lab or in the field. Syrinx permits flexible modeling of complex vocal interactions in an interactive playback setting. Large numbers of sounds can be stored on disk as digital wave files for instant recall in the field. The playback trial timer and real-time scrolling spectrographs display of microphone input facilitate the tailoring of playback responses to subtle changes in the vocalizations of playback subjects. Based on our field test of this software in an interactive playback experiment with Black-capped ChickadeesPoecile atricapillus, we conclude that Syrinx is a versatile and user-friendly tool for performing interactive playback with a minimum of equipment.

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753451

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753452

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.2000.9753445

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor