Table 1.
Main effects of (a) age, (b) season, and (c) social context on within-male changes in trill consistency, vocal deviation, bandwidth, and note rate. Columns show the dependent variable with the power exponent used for transformation, sample sizes of birds and songs, F and p values for each test, and least squares means for each state in the comparison. Significant results, shown in bold, remained significant after correction for multiple tests. Bird ID was significant in all cases (p < 0.0001)
| (a) Age | N birds (songs) | F | p | Younger LSM (±SE) | Older LSM (±SE) |
|---|---|---|---|---|---|
| Consistency ^3 | 17 (788) | 8.632 | 0.0034 | 0.877 (0.0015) | 0.896 (0.0015) |
| Vocal deviation ^0.8 | 17 (793) | 11.74 | 0.0006 | 0.939 (0.0115) | 0.881 (0.0117) |
| Bandwidth (Hz) ^2.2 | 17 (793) | 38.29 | <0.0001 | 3496 (11.61) | 3591 (11.77) |
| Note rate ^0.05 | 17 (793) | 16.02 | <0.0001 | 4.929 (0.0057) | 4.901 (0.0058) |
| (b) Season | N birds (songs) | F | p | Early LSM (±SE) | Later LSM (±SE) |
|---|---|---|---|---|---|
| Consistency ^5 | 30 (919) | 8.584 | 0.0035 | 0.864 (0.0017) | 0.871 (0.0016) |
| Vocal deviation ^0.6 | 30 (955) | 0.031 | 0.879 | 0.985 (0.0125) | 0.992 (0.0118) |
| Bandwidth (Hz) ^3.3 | 30 (955) | 1.079 | 0.299 | 3620 (12.24) | 3594 (11.48) |
| Note rate ^0.1 | 30 (955) | 23.94 | <0.0001 | 4.681 (0.0055) | 4.714 (0.0051) |
| (c) Social context | N birds (songs) | F | p | Dawn chorus LSM (±SE) | Playback LSM (±SE) |
|---|---|---|---|---|---|
| Consistency ^3 | 14 (332) | 1.027 | 0.312 | 0.881 (0.0023) | 0.878 (0.0025) |
| Vocal deviation ^0.6 | 14 (344) | 0.879 | 0.349 | 1.131 (0.0163) | 1.159 (0.0177) |
| Bandwidth (Hz) ^2.2 | 14 (344) | 9.097 | 0.0028 | 3370 (15.52) | 3296 (16.86) |
| Note rate ^0.1 | 14 (344) | 41.28 | <0.0001 | 4.809 (0.0084) | 4.887 (0.0091) |