a | Uropygial gland volume | Â | Â | Â | Â | Â |
 |  |  | Estimate ± SE | df | F | P |
 | Year |  | 0.20 ± 0.04 | 1,52 | 29.6 | <0.001 |
 | Wing length |  | 0.53 ± 0.12 | 1,36 | 19.6 | <0.001 |
 | Treatment | Nisin | −0.05 ± 0.06 | 2,52 | 1.2 | 0.31 |
 |  | TSB | −0.09 ± 0.06 |  |  |  |
 | Sex |  | 0.49 ± 0.08 | 1,36 | 41.2 | <0.001 |
 | Treatment × Sex | Nisin | 0.20 ± 0.09 | 2,36 | 4.2 | 0.018 |
 |  | TSB | 0.24 ± 0.09 |  |  |  |
b | Uropygial gland composition - PC1 | Â | Â | Â | Â | |
 |  |  | Estimate ± SE | df | F | P |
 | Treatment | Nisin | 0.04 ± 0.14 | 2,28 | 3.7 | 0.033 |
 |  | TSB | −0.30 ± 0.15 |  |  |  |
 | Sex |  | 0.72 ± 0.12 | 1,22 | 38.6 | <0.001 |
c | Uropygial gland composition - PC2 | Â | Â | Â | Â | |
 |  |  | Estimate ± SE | df | F | P |
 | Date |  | 0.05 ± 0.02 | 1,19 | 5.7 | 0.021 |
 | Treatment | Nisin | 2.29 ± 0.58 | 2,28 | 8.8 | <0.001 |
 |  | TSB | 1.97 ± 0.60 |  |  |  |
 | Sex |  | −2.89 ± 0.69 | 1,19 | 17.3 | <0.001 |
 | Treatment × Sex | Nisin | 2.36 ± 0.91 | 2,19 | 5.2 | 0.01 |
 |  | TSB | 2.81 ± 0.92 |  |  |  |
d | Uropygial gland composition - PC3 | Â | Â | Â | Â | |
 |  |  | Estimate ± SE | df | F | P |
 | Sex |  | −1.34 ± 0.35 | 1,22 | 39.5 | <0.001 |