Table 2.
Effects on the number of young fledged per egg laid, and pre-fledging body mass of nestlings.
| Source of variation | F | df | P |
|---|---|---|---|
| Effects on fledging success | |||
| Treatment | 4.98 | 1, 41 | 0.0311 |
| Species | 2.19 | 1, 41 | 0.1464 |
| Effects on pre-fledging body mass | |||
| Treatment | 0.55 | 1, 35.9 | 0.4626 |
| Tarsus length | 159.64 | 1, 134.0 | <0.0001 |
| Species | 20.07 | 1, 67.6 | <0.0001 |
| Banding date | 5.27 | 1, 36.2 | 0.0276 |
| Treatment × species | 6.13 | 1, 35.6 | 0.0182 |
Fledging success was analysed using a generalized linear model assessing the number of young fledged in “successes/trials” syntax (see methods). Pre-fledging body mass was analysed using a linear mixed model with nest identity as a random effect to account for the non-independence of siblings within broods (the random effect of brood explained 11.8% of the variation observed in nestling mass).