Abstract # 158:

Scheduled for Friday, June 22, 2007 05:00 PM-07:00 PM: Session 14 (South Main Hall) Poster Presentation

Preliminary analyses suggest that acoustic features of captive Garnett’s bushbaby (Otolemur garnettii) barks may be distinctive by individual and sex

S. E. Kessler1, L. T. Nash1, S. L. Watson2, K. Manning2 and D. Hanbury2
1Arizona State University, School of Human Evolution and Social Change , Box 872402, Tempe, AZ 85287-2402, USA, 2Psychology Department, University of Southern Mississippi
     Otolemur garnettii loud calls are a series of barks. Loud calls are the first contact between individuals who are too far apart for visual or olfactory cues and may have a crucial role in maintaining the species’ dispersed social networks. We recorded vocalizations from eight adults (four males and four females) housed at the University of Southern Mississippi using a Sennheiser ME66 short shotgun microphone and a Sony MZNH900 hi minidisc recorder. We created spectrograms with Raven 1.2.1 and measured the first harmonic and four formants. Each variable was tested within each individual for the effects of order within calling bout using Bonferroni adjusted t-tests and ANOVAs run in SYSTAT 11. Thirty-nine of forty tests were nonsignificant [individual-wide a=0.05]. We conducted Bonferroni adjusted nested ANOVAs on fifteen randomly selected barks from each individual and found that the effects of individual, nested within sex, were significant for all variables and that sex was significant for all but the second formant [test-wide a=0.05]. These results suggest that barks may have the acoustic potential to either allow the listener to discern the caller’s sex and identity or aid in such discrimination when in combination with other acoustic variables. Further analyses will be conducted using discriminant function statistics. Whether the bushbabies perceive these differences has not yet been tested.