Figure 1.
Distance moved from original sound playbacks and from vocalization playbacks.
A) Distance moved (mean ± SEM) from playbacks of white noise controls (n = 13), Samburu voices (n = 14) and bee sounds (n = 15). B) Distance moved (mean ± SEM) from four vocalization playback stimuli (all n = 10). wn* = significantly different from white noise.
Table 1.
Behavioral responses to original sound playbacks.
Figure 2.
Behavioral response to original sound playbacks and to vocalization playbacks.
A) Vigilance (mean ± SEM) across phases of playback trials for white noise (n = 13), Samburu voices (n = 14) and bee sounds (n = 15). B) Vigilance (mean ± SEM) across phases of playback trials for four vocalization playbacks (all n = 10). C) Headshaking (mean ± SEM) across phases of playback trials for white noise (n = 13), Samburu voices (n = 14) and bee sounds (n = 15). D) Headshaking (mean ± SEM) across phases of playback trials for all four vocalization playbacks (all n = 10). Pre = pre-stimulus phase; Stm = stimulus phase; Pst = post-stimulus phase. *pre = significantly different from pre-stimulus phase.
Figure 3.
Call rate in response to original sound playbacks.
Call rate (mean ± SEM) across phases of playback trials for white noise (n = 13), Samburu voices (n = 14) and bee sounds (n = 15). Pre = pre-stimulus phase; Stm = stimulus phase; Pst = post-stimulus phase. *pre = significantly different from pre-stimulus phase.
Figure 4.
Acoustic structure of rumbles made in response to original sound playbacks.
Acoustic features (mean ± SEM) of rumbles produced during pre-stimulus control phases (n = 18), and in response to Samburu voices (n = 20) and bee sounds (n = 20). A) Mean fundamental frequency (F0). B) F0 range. C) The first formant (F1) location. D) F2 location. *con = significantly different from controls. *bee = significantly different from bee sounds.
Table 2.
Acoustic structure of rumbles produced during pre-stimulus phases (controls), and in response to Samburu voices and bee sounds.
Figure 5.
Spectrograms of elephant vocalization playback stimuli.
A) Samburu multi-call alarm: unmodified vocal response to Samburu voice playback, with rumbles (black arrows) and roars and trumpets (white arrows). Nonlinear phenomena include chaos in roars, and bifurcation in one rumble (R3) and the second roar which transitions to a rumble (R4). B) Samburu rumble alarm: same as (A) but with roars and trumpets removed. Rumbles overlapping with roars (R2 and second half of R3) were simultaneously removed. The remaining rumbles were doubled. First and second formant (F1, F2) locations are indicated. C) Modified Samburu rumble alarm: same as (B) but with F2 lowered to resemble control rumbles. See Materials and Methods for details. Spectrograms were created in Adobe Audition (version 2.0, 44.1 kHz sample rate, frequency resolution = 8192 bands, Gaussian window).
Table 3.
Behavioral responses to vocalization playback stimuli.
Table 4.
Acoustic features of control rumbles and 6 vocalization playback stimuli, and behavioral responses to playbacks.