Table 1 Descriptive statistics of parameters related to the spectral structure and temporal patterns of squeaks. The mean is calculated over the individual mean values except for those variables with a preceding “total” (calculated over total sample size)
From: A novel theory of Asian elephant high-frequency squeak production
Nsubject | Ncalls | Ncalls/subject | Minimum | Maximum | Range individual means | Mean (±SD) | |
|---|---|---|---|---|---|---|---|
General spectral structure | |||||||
Mean F0 frequency (Hz) | 10 | 224 | 10–29 | 291.84 | 2001.72 | 471.84–1536.76 | 813.07 ± 318.72 |
Dominant frequency (Hz) | 10 | 238 | 9–34 | 421.90 | 3079.20 | 565.74–1609.93 | 978.27 ± 378.31 |
Percent calls per subject with DFR on 2. harmonic (%) | 10 | 230 | 9–29 | 0.00 | 91.00 | – | 18.00 ± 3.00 |
HNR (dB) | 7 | 107 | 7–24 | 1.01 | 26.86 | 3.93–14.91 | 11.00 ± 3.55 |
Percent of calls per subject with at least one NLP (%) | 10 | 213 | 2–41 | 73.68 | 100 | – | 97.12 ± 8.27 |
2.-1. Spectral peak (dB) | 10 | 209 | 4–24 | −31.00 | 16.50 | −15.42 - 8.47 | −5.52 ± 6.55 |
3.-2. Spectral peak (dB) | 7 | 78 | 4–16 | −4.20 | 26.60 | −14.77 - 7.52 | −3.99 ± 6.69 |
4.-3. Spectral peak (dB) | 7 | 31 | 1–10 | −1.00 | 21.10 | – | total 8.39 ± 5.92 |
Sound pressure level (dB) | 2 | 10 | 3–7 | 58 | 96 | – | total 76.22 ± 11.54 |
Temporal patterns | |||||||
Percent of calls uttered in bouts per subject (%) | 15 | 976 | 12–244 | 52.94 | 100 | – | 79.3 ± 18.01 |
Number of calls per bout | 15 | 1036 Bouts 154 | 12–244 Bouts 2–29 | 2 | 25 | 2.67–8.79 | 4.89 ± 2.11 |
Call duration (s) | 13 | 765 | 13–244 | 0.04 | 4.49 | 0.14–2.04 | 0.47 ± 0.51 |
Interval duration (s) | 13 | Bouts 113 Interval 498 | 3–23 4–144 | 0.03 | 3.42 | 0.14–1.12 | 0.50 ± 0.32 |