Table 2. The effect of parental age and breeding parameters of natal broods on the probability of male offspring.
The study was performed on Blackbirds (Turdus merula) in the Żeromski Park (Szczecin, NW Poland) in 2005–2007 and 2016–2017.
| n = 382 | Estimate | se/sd | Chi2 | P |
|---|---|---|---|---|
| (Intercept) | −0.330 | 0.729 | ||
| Age difference | 0.132 | 0.052 | 6.725 | 0.009 |
| Hatching date | −0.003 | 0.004 | 0.605 | 0.437 |
| Clutch sequence | 0.099 | 0.119 | 0.682 | 0.408 |
| Offspring hatching sequence | −0.103 | 0.102 | 1.023 | 0.312 |
| r(Nest ID) | 0.038 | 0.194 | ||
| r(Offspring hatching sequence) | 0.023 | 0.153 |
Notes.
Estimated parameters of the generalised linear mixed model with binomial error distribution. Parameters of natal broods: nestling hatching date, clutch sequence in the breeding season, offspring hatching sequence in the nest.
- r
- random effect