Table 3. Summary of the 18 GLMMs testing for various acoustic parameters of pant hoots produced by five chimpanzee males.
Test predictors included period of instability, caller rank, and whether leaf clipping preceded the pant hoot. Sample size refers to the total number of pant hoots per GLMM.
| Response variable | Transformation of response | Error structure (link function) | Sample size | Full vs null model comparison | |
|---|---|---|---|---|---|
| Total duration (s) | sqrt | Gaussian (identity) | 212 | χ2 = 15.03, df = 4, P = 0.0046 | |
| Introduction | # calls in the introduction | none | Poisson (log) | 173 | χ2 = 12.56, df = 4, P = 0.014 |
| Introduction duration (s) | sqrt | Gaussian (identity) | 173 | χ2 = 12.52, df = 4, P = 0.014 | |
| F0 of last call of the introduction (Hz) | sqrt | Gaussian (identity) | 173 | χ2 = 5.67, df = 4, P = 0.23 | |
| Duration of the last call of the introduction (s) | none | Gaussian (identity) | 173 | χ2 = 5.35, df = 4, P = 0.25 | |
| pF of the last call of the introduction (Hz) | log | Gaussian (identity) | 173 | χ2 = 6.10, df = 4, P = 0.19 | |
| Build-up | # of voiced calls in the build-up | none | Negative Binomial (log) | 189 | χ2 = 12.16, df = 4, P = 0.016 |
| Duration of the build-up (s) | sqrt | Gaussian (identity) | 189 | χ2 = 0.00, df = 4, P = 1.00 | |
| F0 of the middle call of the build-up (Hz) | sqrt | Gaussian (identity) | 189 | χ2 = 18.10, df = 4, P = 0.0012 | |
| Duration of the middle call of the build-up | log (×1000) | Gaussian (identity) | 189 | χ2 = 13.87, df = 4, P = 0.0077 | |
| pF of the middle call of the build-up (Hz) | log | Gaussian (identity) | 189 | χ2 = 16.11, df = 4, P = 0.0029 | |
| Climax | # of elements in the climax | none | Negative Binomial (log) | 189 | χ2 = 28.59, df = 4, P = 0.00001 |
| Duration of the climax (s) | sqrt | Gaussian (identity) | 189 | χ2 = 21.61, df = 4, P = 0.00024 | |
| F0 of the highest call of the climax (Hz) | none | Gaussian (identity) | 127 | χ2 = 7.27, df = 4, P = 0.12 | |
| Duration of the highest call of the climax (s) | none | Gaussian (identity) | 127 | χ2 = 2.46, df = 4, P = 0.65 | |
| pF of the highest call of the climax (Hz) | log | Gaussian (identity) | 127 | χ2 = 11.28, df = 4, P = 0.024 | |
| Duration of drumming (s)a | sqrt | Gaussian (identity) | 210 | χ2 = 33.06, df = 4, P < 0.00001 | |
| # of drum beatsa | none | Negative Binomial (log) | 210 | χ2 = 24.01, df = 4, P = 0.00008 |
Notes.
a
Drumming could start in the build-up or climax but usually occurred solely in the climax phase.