Table 1.
Sources of variation in (a) repertoire size and (b) HVC volume in adult male canaries (Serinus canaria).
| F-ratio | coefficient | p | |
|---|---|---|---|
| (a) independent variables in the final model | |||
| treatment | 25.67 | NA | 0.0001 |
| haematocrit reading (%rbc) | 18.63 | −0.4334 | 0.001 |
| bird origin (hand reared or supplier bought) | 0.56 | NA | 0.467 |
| origin×treatment | 3.51 | NA | 0.081 |
| excluded independent variables | |||
| basal corticosterone (ng ml−1) | 0.05 | 0.0209 | 0.821 |
| cell-mediated immune response | 0.16 | 0.7350 | 0.693 |
| adult mass (g) | 0.19 | −1.0250 | 0.673 |
| testosterone (ng ml−1) | 1.25 | 0.9427 | 0.282 |
| number complex syllables | 1.53 | 0.4871 | 0.237 |
| final model R2=0.67, residual d.f.=15 | |||
| (b) independent variables in the final model | |||
| treatment | 8.14 | NA | 0.013 |
| number complex syllables | 5.29 | −0.0317 | 0.037 |
| haematocrit reading (%rbc) | 4.08 | −0.0084 | 0.063 |
| bird origin (hand reared or supplier bought) | 4.01 | NA | 0.065 |
| origin×treatment | 4.28 | NA | 0.058 |
| excluded independent variables | |||
| adult mass (g) | 0.01 | 0.0012 | 0.910 |
| testosterone (ng ml−1) | 0.41 | 0.0221 | 0.530 |
| basal corticosterone (ng ml−1) | 0.76 | −0.0021 | 0.399 |
| cell-mediated immune response | 1.86 | 0.0686 | 0.195 |
| final model R2=0.51, residual d.f.=14 |
Table shows the results of a General Linear Model (Minitab, PA, USA). Terms excluded due to non-significance are shown at the bottom of each table. Significant terms are shown in bold. The model also controlled for the origin of the birds. NA signifies a coefficient is not applicable as this term is a factor.