Table 2.
Effects of female traits and climatic variables on the number of fledglings
| Sources of variation | Estimate | SE | z | P |
|---|---|---|---|---|
| Conditional model (N = 7315 broods of 5513 females) | ||||
| Intercept | 1.52 | 0.02 | 69.11 | < 0.001 |
| Female age | − 0.01 | 0.01 | − 0.83 | 0.41 |
| Female body condition | 0.00 | 0.01 | − 0.13 | 0.90 |
| Within-year temperature: incubation | 0.00 | 0.01 | 0.43 | 0.67 |
| Between-year temperature: incubation | 0.01 | 0.02 | 0.47 | 0.64 |
| Within-year precipitation: incubation | 0.00 | 0.01 | 0.16 | 0.87 |
| Between-year precipitation: incubation | 0.03 | 0.02 | 1.71 | 0.088 |
| Within-year temperature: nestlings | 0.02 | 0.01 | 1.44 | 0.15 |
| Between-year temperature: nestlings | − 0.02 | 0.02 | − 0.86 | 0.39 |
| Within-year precipitation: nestlings | − 0.01 | 0.01 | − 1.79 | 0.073 |
| Between-year precipitation: nestlings | − 0.04 | 0.02 | − 1.69 | 0.092 |
| Laying date | − 0.07 | 0.02 | − 4.07 | < 0.001 |
| Clutch size | 0.09 | 0.01 | 12.38 | < 0.001 |
| Female ID random | 0.00 | |||
| Plot ID random | 0.05 | |||
| Year of study random | 0.10 | |||
| Pseudo-R2marginal/conditional | 0.08/0.13 | |||
| Zero-inflated model (N = 7315 broods of 5513 females) | ||||
| Intercept | − 1.96 | 0.18 | − 11.03 | < 0.001 |
| Female age | 0.07 | 0.08 | 0.87 | 0.38 |
| Female body condition | 0.04 | 0.04 | 1.16 | 0.24 |
| Within-year temperature: incubation | − 0.07 | 0.05 | − 1.47 | 0.14 |
| Between-year temperature: incubation | − 0.28 | 0.19 | − 1.44 | 0.15 |
| Within-year precipitation: incubation | − 0.02 | 0.04 | − 0.53 | 0.60 |
| Between-year precipitation: incubation | − 0.19 | 0.14 | − 1.32 | 0.19 |
| Within-year temperature: nestlings | − 0.15 | 0.04 | − 3.45 | < 0.001 |
| Between-year temperature: nestlings | 0.25 | 0.20 | 1.22 | 0.22 |
| Within-year precipitation: nestlings | 0.12 | 0.04 | 2.94 | 0.003 |
| Between-year precipitation: nestlings | 0.31 | 0.18 | 1.78 | 0.076 |
| Laying date | 0.73 | 0.08 | 8.94 | < 0.001 |
| Clutch size | 0.11 | 0.04 | 2.86 | 0.004 |
| Female ID random | 0.00 | |||
| Plot ID random | 0.47 | |||
| Year of study random | 0.87 | |||
Output of the zero-inflated generalized linear mixed model with Poisson error distribution and the log-link function for a conditional component and with binomial error distribution and the logit-link function for a zero-inflated component testing how female age (categorical predictor), female body condition, the within- and between-year effects of ambient temperature and sum of precipitation experienced during the incubation and nestling period, laying date, and clutch size (all as continuous predictors), affect the number of fledglings. All continuous explanatory terms were standardized. The female identity, study plot identity, and year of study were included as random factors. Significant terms P < 0.05 are in bold