Table 2.
Parameter estimates from the statistically best-supported binomial generalized linear mixed-effects models (GLMMs) for age-specific change in annual breeding success. Model 1218 from Table1 is shown, analyzing 12 789 records from 416 female elephants. Parameter estimates and standard errors (SE) are shown on the logit scale. ‘Age: AgeGroup (X)’ denotes an interaction between age as a linear covariate and age group, where the numbers in parentheses indicate the boundaries of the grouping. Note that age at first reproduction, age at last observation (LastAge) and Age were divided by 100 to aid model convergence.
| Variable | Estimate | SE | z | P |
|---|---|---|---|---|
| Fixed effects | ||||
| Intercept | −6.3010 | 1.1694 | −5.39 | <0.001 |
| Censored (0) | 0.0000 | 0.0000 | ||
| Censored (1) | 0.0086 | 0.0781 | 0.11 | 0.913 |
| AFR | −7.5900 | 0.6895 | −11.01 | <0.001 |
| LastAge | −0.5665 | 0.4588 | −1.24 | 0.217 |
| Age | 29.4712 | 11.4487 | 2.57 | 0.010 |
| AgeGroup (5–12) | 0.0000 | 0.0000 | ||
| AgeGroup (13–18) | 1.8569 | 1.3511 | 1.37 | 0.169 |
| AgeGroup (19+) | 6.4823 | 1.1651 | 5.56 | <0.001 |
| Age: AgeGroup (5–12) | 0.0000 | 0.0000 | ||
| Age: AgeGroup (13–18) | −5.8405 | 12.2471 | −0.48 | 0.633 |
| Age: AgeGroup (19+) | −30.7517 | 11.4613 | −2.68 | 0.007 |
| Random effects | ||||
| ID | 0.0000 | 0.0000 | ||
| Year | 0.0125 | 0.0150 | ||